Search results for: microbial metabolites

Authors: Azri Yamina Mounia, Zitouni Dalila, Aziza Majda, Tou Insaf, Sadi Meriem

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To confront the fossil fuel crisis and the consequences of global warning, many efforts were devoted to develop alternative electricity generation and attracted numerous researchers, especially in the microbial fuel cell field, because it allows generating electric energy and degrading multiple organics compounds at the same time. However, one of the main constraints on power generation is the slow rate of oxygen reduction at the cathode electrode. This paper describes the potential of algal biomass (Chlorella vulgaris) as photosynthetic cathodes, eliminating the need for a mechanical air supply and the use of often expensive noble metal cathode catalysts, thus improving the sustainability and cost-effectiveness of the MFC system. During polarizations, MFC power density using algal biomass was 0.4mW/m², whereas the MFC with mechanic aeration showed a value of 0.2mW/m². Chlorella vulgaris was chosen due to its fastest growing. C. vulgaris grown in BG11 medium in sterilized Erlenmeyer flask. C. vulgaris was used as a bio‐cathode. Anaerobic activated sludge from the plant of Beni‐Messous WWTP(Algiers) was used in an anodic compartment. A dual‐chamber reactor MFC was used as a reactor. The reactor has been fabricated in the laboratory using plastic jars. The cylindrical and rectangular jars were used as the anode and cathode chambers, respectively. The volume of anode and cathode chambers was 0.8 and 2L, respectively. The two chambers were connected with a proton exchange membrane (PEM). The plain graphite plates (5 x 2cm) were used as electrodes for both anode and cathode. The cyclic voltammetry analysis of oxygen reduction revealed that the cathode potential was proportional to the amount of oxygen available in the cathode surface electrode. In the case of algal aeration, the peak reduction value of -2.18A/m² was two times higher than in mechanical aeration -1.85A/m². The electricity production reached 70 mA/m² and was stimulated immediately by the oxygen produced by algae up to the value of 20 mg/L.

Keywords: Chlorella vulgaris, cyclic voltammetry, microbial fuel cell, oxygen reduction

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Authors: Okugbe Ebiotubo Ohore, Jingli Zhang, Binessi Edouard Ifon, Mathieu Nsenga Kumwimba, Xiaoying Mu, Dai Kuang, Zhen Wang, Ji-Dong Gu, Guojing Yang

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Antibiotic pollution and the evolution of antibiotic resistance genes (ARGs) are increasingly viewed as major threats to both ecosystem security and human health, and has drawn attention. This study investigated the fate of antibiotics in aqueous and sedimentary substrates and the impact of ecosystem shifts between water and sedimentary phases on resistome profiles. The findings indicated notable variations in the concentration and distribution patterns of antibiotics across various environmental phases. Based on the partition coefficient (Kd), the total antibiotic concentration was significantly greater in the surface water (1405.45 ng/L; 49.5%) compared to the suspended particulate matter (Kd =0.64; 892.59 ng/g; 31.4%) and sediment (Kd=0.4; 542.64 ng/g; 19.1%). However, the relative abundance of ARGs in surface water and sediment was disproportionate to the abundance of antibiotics concentration, and sediments were the predominant ARGs reservoirs. Phylogenetic divergence of the microbial communities between the surface water and the sedimentary ecosystems potentially played important roles in driving the ARGs profiles between the two distinctive ecosystems. ARGs of Clinical importance; including blaGES, MCR-7.1, ermB, tet(34), tet36, tetG-01, and sul2 were significantly increased in the surface water, while blaCTX-M-01, blaTEM, blaOXA10-01, blaVIM, tet(W/N/W), tetM02, and ermX were amplified in the sediments. cfxA was an endemic ARG in surface-water ecosystems while the endemic ARGs of the sedimentary ecosystems included aacC4, aadA9-02, blaCTX-M-04, blaIMP-01, blaIMP-02, bla-L1, penA, erm(36), ermC, ermT-01, msrA-01, pikR2, vgb-01, mexA, oprD, ttgB, and aac. These findings offer a valuable information for the identification of ARGs-specific high-risk reservoirs.

Keywords: antibiotic resistance genes, microbial diversity, suspended particulate matter, sediment, surface water

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Authors: Abazar Ghorbani, W. M. Wishwajith W. Kandegama, Seyed Mehdi Razavi, Moxian Chen

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The roles of hydrogen sulfide (H₂S) and melatonin (MT) as gasotransmitters in plants are widely recognised. Nevertheless, the precise nature of their involvement in defensive reactions remains uncertain. This study investigates the impact of the ML-H2S interaction on tomato plants exposed to vanadium (V) toxicity, focusing on synthesising secondary metabolites and V metal sequestration. The treatments applied in this study included a control (T1), V stress (T2), MT+V (T3), MT+H2S+V (T4), MT+hypotaurine (HT)+V (T5), and MT+H2S+HT+V (T6). These treatments were administered: MT (150 µM) as a foliar spray pre-treatment (3X), HT treatment (0.1 mM, an H2S scavenger) as root immersion for 12 hours as pre-treatments, and H2S (NaHS, 0.2 mM) and V (40 mg/L) treatments added to the Hoagland solution for 2 weeks. Results demonstrate that ML and H2S+ML treatments alleviate V toxicity by promoting the transcription of key genes (ANS, F3H, CHS, DFR, PAL, and CHI) involved in phenolic and anthocyanin biosynthesis. Moreover, they decreased V uptake and accumulation and enhanced the transcription of genes involved in glutathione and phytochelatin synthesis (GSH1, PCS, and ABC1), leading to V sequestration in roots and protection against V-induced damage. Additionally, ML and H2S+ML treatments optimize chlorophyll metabolism, and increase internal H2S levels, thereby promoting tomato growth under V stress. The combined treatment of ML+H2S shows superior effects compared to ML alone, suggesting synergistic/interactive effects between these two substances. Furthermore, inhibition of the beneficial impact of ML+H2S and ML treatments by HT, an H2S scavenger, underscores the significant involvement of H₂S in the signaling pathway activated by ML during V toxicity. Overall, these findings suggest that ML requires the presence of endogenous H₂S to mitigate V-induced adverse effects on tomato seedlings.

Keywords: vanadium toxicity, secondary metabolites, vanadium sequestration, h2s-melatonin crosstalk

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Authors: Vanja Vlajkov, Ivana PajčIn, Mila Grahovac, Marta Loc, Dragana Budakov, Jovana Grahovac

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The rhizosphere soil refers to the plant roots' dynamic environment characterized by their inhabitants' high biological activity. Rhizospheric bacteria are recognized as effective biocontrol agents and considered cardinal in alternative strategies for securing ecological plant diseases management. The need to suppress fungal pathogens is an urgent task, not only because of the direct economic losses caused by infection but also due to their ability to produce mycotoxins with harmful effects on human health. Aspergillus and Fusarium species are well-known producers of toxigenic metabolites with a high capacity to colonize crops and enter the food chain. The bacteria belonging to the Bacillus genus has been conceded as a plant beneficial species in agricultural practice and identified as plant growth-promoting rhizobacteria (PGPR). Besides incontestable potential, the full commercialization of microbial biopesticides is in the preliminary phase. Thus, there is a constant need for estimating the suitability of novel strains to be used as a central point of viable bioprocess leading to market-ready product development. In the present study, 76 potential producing strains were isolated from the rhizosphere soil, sampled from different localities in the Autonomous Province of Vojvodina, Republic of Serbia. The selective isolation process of strains started by resuspending 1 g of soil samples in 9 ml of saline and incubating at 28° C for 15 minutes at 150 rpm. After homogenization, thermal treatment at 100° C for 7 minutes was performed. Dilution series (10-1-10-3) were prepared, and 500 µl of each was inoculated on nutrient agar plates and incubated at 28° C for 48 h. The pure cultures of morphologically different strains indicating belonging to the Bacillus genus were obtained by the spread-plate technique. The cultivation of the isolated strains was carried out in an Erlenmeyer flask for 96 h, at 28 °C, 170 rpm. The antagonistic activity screening included two phytopathogenic fungi as test microorganisms: Aspergillus sp. and Fusarium sp. The mycelial growth inhibition was estimated based on the antimicrobial activity testing of cultivation broth by the diffusion method. For the Aspergillus sp., the highest antifungal activity was recorded for the isolates Kro-4a and Mah-1a. In contrast, for the Fusarium sp., following 15 isolates exhibited the highest antagonistic effect Par-1, Par-2, Par-3, Par-4, Kup-4, Paš-1b, Pap-3, Kro-2, Kro-3a, Kro-3b, Kra-1a, Kra-1b, Šar-1, Šar-2b and Šar-4. One-way ANOVA was performed to determine the antagonists' effect statistical significance on inhibition zone diameter. Duncan's multiple range test was conducted to define homogenous groups of antagonists with the same level of statistical significance regarding their effect on antimicrobial activity of the tested cultivation broth against tested pathogens. The study results have pointed out the significant in vitro potential of the isolated strains to be used as biocontrol agents for the suppression of the tested mycotoxigenic fungi. Further research should include the identification and detailed characterization of the most promising isolates and mode of action of the selected strains as biocontrol agents. The following research should also involve bioprocess optimization steps to fully reach the selected strains' potential as microbial biopesticides and design cost-effective biotechnological production.

Keywords: Bacillus, biocontrol, bioprocess, mycotoxigenic fungi

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Authors: Sonia Mbarki Marian Brestic, Artemio Cerda Naceur Jedidi, Jose Antonnio Pascual Chedly Abdelly

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Monitoring the effect addition bio-amendment as compost to an agricultural soil for growing plant lolium perenne irrigated with a CdCl2 solution at 50 µM on physicochemical soils characteristics and plant production in laboratory condition. Even microbial activity indexes (acid phosphatase, β-glucosidase, urease, and dehydrogenase) was determined. Basal respiration was the most affected index, while enzymatic activities and microbial biomass showed a decrease due to the cadmium treatments. We noticed that this clay soil with higher pH showed inhibition of basal respiration. Our results provide evidence for the importance of ameliorating effect compost on plant growth even when soil was added with cadmium solution at 50 µmoml.l-1. Soil heavy metal concentrations depended on heavy metals types, increased substantially with cadmium increase and with compost addition, but the recorded values were below the toxicity limits in soils and plants except for cadmium.

Keywords: compost, enzymatic activity, lolium perenne, bioremediation

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Authors: Niranjan Mukherjee, Burga Braun, Ulrich Szewzyk

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Recalcitrant pharmaceuticals are increasingly found in urban water systems forced by demographic changes. The groundwater-surface water interface, or the hyporheic zone, is known for its impressive self-purification capacity of water bodies. Redox gradients present in this zone provide a wide range of electron acceptors and harbour diverse microbial communities. Biotic transformations of pharmaceuticals in this zone have been demonstrated, but not much information is available on the kind of communities bringing about these transformations. Therefore, bioreactors using sediment from the hyporheic zone of a river in Berlin were set up and fed with iopromide, a recalcitrant iodinated X-ray contrast medium. Iopromide, who’s many oxic and anoxic transformation products have been characterized, was shown to be transformed in such a bioreactor as it passes along the gradient. Many deiodinated transformation products of iopromide could be identified at the outlet of the reactor. In our experiments, it was seen that at the same depths of the column, the transformation of iopromide increased over time. This could be an indication of the microbial communities in the sediment adapting to iopromide. The hyporheic zone, with its varying redox conditions, mainly due to the upwelling and downwelling of surface and groundwater levels, could potentially provide microorganisms with conditions for the complete transformation of recalcitrant pharmaceuticals.

Keywords: iopromide, hyporheic zone, recalcitrant pharmaceutical, redox gradients

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Authors: Nourhan G. Sahly, Ahmed Moustafa, Mohamed S. Zaghloul, Tamer Z. Salem

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The gut microbiome plays important roles in the human body that includes but not limited to digestion, immunity, homeostasis and response to some drugs such as chemotherapy and immunotherapy. Its role has also been linked to radiotherapy and associated gastrointestinal injuries, where the microbial dysbiosis could be the driving force for dose determination or the complete suspension of the treatment protocol. Linking the gut microbiota alterations to different cancer treatment protocols is not easy especially in humans. However, enormous effort was exerted to understand this complex relationship. In the current study, we described the gut microbiota dysbiosis in pediatric sarcoma patients, in the pelvic region, with regards to radiotherapy and antibiotics. Fecal samples were collected as a source of microbial DNA for which the gene encoding for V3-V5 regions of 16S rRNA was sequenced. Two of the three patients understudy had experienced an increase in alpha diversity post exposure to 50.4 Gy. Although phylum Firmicutes overall relative abundance has generally decreased, six of its taxa increased in all patients. Our results may indicate the possibility of radiosensitivity or enrichment of the antibiotic resistance of the elevated taxa. Further studies are needed to describe the extent of radiosensitivity with regards to antibiotic resistance.

Keywords: combined radiotherapy and chemotherapy, gut microbiome, pediatric cancer, radiosensitivity

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Authors: Raana Babadi Fathipour

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The production of dairy holds significant importance in the sustenance of billions of individuals worldwide, as they rely on milk and its derived products for daily consumption. In addition to being a source of essential nutrients crucial for human well-being, such as proteins, fats, vitamins, and minerals; dairy items are witnessing an increasing demand worldwide. Amongst all the factors contributing to the quality and safety assurance of dairy products, the strong focus lies on maintaining high standards in raw milk procurement. Raw milk serves as an externally nutritious medium for various microorganisms due to its inherent properties. This poses a considerable challenge for the dairy industry in ensuring that microbial contamination is minimized throughout every stage of the value chain. Despite implementing diverse process technologies—both conventional and innovative—the occurrence of microbial spoilage still results in substantial losses within this industry context. Moreover, milk and dairy products have been associated with numerous cases of foodborne illnesses across the globe. Various pathogens such as Salmonella serovars, Campylobacter spp., Shiga toxin-producing Escherichia coli, Listeria monocytogenes, and enterotoxin producing Staphylococcus aureus are commonly identified as the culprits behind these outbreaks in the dairy industry. The effective management of food safety within this sector necessitates a proactive and risk-based approach to reform. However, this strategy presents difficulties for developing nations where informal value chains dominate the dairy sector. Whether operating on a small or large scale or falling within formal or informal realms, it is imperative that the dairy industry adheres to principles of good hygiene practices and good manufacturing practices. Additionally, identifying and managing potential sources of contamination is crucial in mitigating challenges pertaining to quality and safety precautions.

Keywords: dairy value chain, microbial contamination, food safety, hygiene

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Authors: Judith Mogouong, Philippe Constant, Robert Lavallee, Claude Guertin

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The emerald ash borer (EAB) is an exotic wood borer insect native from China, which is associated with important environmental and economic damages in North America. Beetles are known to be vectors of microbial communities related to their adaptive capacities. It is now established that environmental stress factors may induce physiological events on the host trees, such as phytochemical changes. Consequently, that may affect the establishment comportment of herbivorous insect. Considering the number of insects collected on ash trees (insects’ density) as an abiotic factor related to stress damage, the aim of our study was to explore the dynamic of EAB gut microbial community genome (microbiome) when facing that factor and to monitor its diversity. Insects were trapped using specific green Lindgren© traps. A gradient of the captured insect population along the St. Lawrence River was used to create three levels of insects’ density (low, intermediate, and high). After dissection, total DNA extracted from insect guts of each level has been sent for amplicon sequencing of bacterial 16S rRNA gene and fungal ITS2 region. The composition of microbial communities among sample appeared largely diversified with the Simpson index significantly different across the three levels of density for bacteria. Add to that; bacteria were represented by seven phyla and twelve classes, whereas fungi were represented by two phyla and seven known classes. Using principal coordinate analysis (PCoA) based on Bray Curtis distances of 16S rRNA sequences, we observed a significant variation between the structure of the bacterial communities depending on insects’ density. Moreover, the analysis showed significant correlations between some bacterial taxa and the three classes of insects’ density. This study is the first to present a complete overview of the bacterial and fungal communities associated with the gut of EAB base on culture-independent methods, and to correlate those communities with a potential stress factor of the host trees.

Keywords: gut microbiome, DNA, 16S rRNA sequences, emerald ash borer

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Authors: Abdelkader Basli, Jean-Claude Delaunay, Eric Pedrot, Jean-Michel Mérillon, Jean-Pierre Monti, Khodir Madani, Mohamed Chibane, Tristan Richard

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The antioxidant and antimicrobial activities of Origanum glandulosum collected in Algeria have been studied. Extract was prepared from aerial part of endemic Algerian oregano. The produced extract has been characterized in terms of total phenols (using Folin method), total flavonoid, antioxidant activities (using the DPPH radical scavenging method and ORAC assay) and microbial activity against four bacteria: Streptococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae one yeast: Candida albicans and one fungi: Aspergillus niger. The results pointed the antioxidant activities of the extract of O. glandulosum and antimicrobial activities against all bacteria and C. Candida, but no effect on A. niger. High performance liquid chromatography combined with mass spectrometry (LC-MS) and nuclear magnetic resonance (LC-NMR) were used to separate and identify the major compounds present in the oregano extract. Rosmarinic acid, globoidnan A and B, lithospermic acid B and three flavonoids were identified.

Keywords: origanum glandulosum, antioxidant, microbial activity, polyphenol, LC-MS, LC-NMR

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Authors: P. Efstathiou, E. Kouskouni, Z. Manolidou, K. Karageorgou, M. Tseroni, A. Efstathiou, V. Karyoti, I. Agrafa

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Aim: The aim of this prospective comparative study is to evaluate the reduction of microbial flora on the surface of an axillary digital thermometer, made of antimicrobial copper, in relation with a common digital thermometer. Material – Methods: A brand new digital electronic thermometer implemented with antimicrobial copper (Cu 70% - Nic 30%, low lead) on the two edges of the device (top and bottom: World Patent Number WO2013064847 and Register Number by the Hellenic Copper Development Institute No 11/2012) was manufactured and a comparative study with common digital electronic thermometer was conducted on 18 ICU (Intensive Care Unit) patients of three different hospitals. The thermometry was performed in accordance with the projected International Nursing Protocols for body temperature measurement. A total of 216 microbiological samples were taken from the axillary area of the patients, using both of the investigated body temperature devises. Simultaneously the “Halo” phenomenon (phenomenon “Stefanis”) was studied at the non-antimicrobial copper-implemented parts of the antimicrobial digital electronic thermometer. Results: In all samples collected from the surface of the antimicrobial electronic digital thermometer, the reduction of microbial flora (Klebsiella spp, Staphylococcus aureus, Staphylococcus epidermitis, Candida spp, Pneudomonas spp) was progressively reduced to 99% in two hours after the thermometry. The above flora was found in the axillary cavity remained the same in common thermometer. The statistical analysis (SPSS 21) showed a statistically significant reduction of the microbial load (N = 216, < 0.05). Conclusions: The hospital-acquired infections are linked to the transfer of pathogens due to the multi-usage of medical devices from both health professionals and patients, such as axillary thermometers. The use of antimicrobial digital electronic thermometer minimizes microbes' transportation between patients and health professionals while having all the conditions of reliability, proper functioning, security, ease of use and reduced cost.

Keywords: antimicrobial copper, cross infections, digital thermometers, ICU

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Authors: Shivankar Agrawal, Sunil Kumar Deshmukh, Colin Barrow, Alok Adholeya

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A variety of genetic and environmental factors cause various cosmetics and dermatological problems. There are already claimed drugs available in market for treating these problems. However, the challenge remains in finding more potent, environmental friendly, causing minimal side effects and economical cosmeceuticals. This leads to an increased demand for natural cosmeceutical products in the last few decades. Plant derived ingredients are limited because plants either contain toxic metabolites, grow too slow or seasonal harvesting is a problem. To identify new bioactive cosmetics ingredients of marine microbial bioresource, we screened 35 marine fungi isolated from marine samples collected from Andaman Island and west coast of India. Fungal crude extracts were investigated for their antityrosinase, antioxidant and antibacterial activities for the purpose of identifying anti-aging, skin-whitening and anti-acne biomolecule with the potential in cosmetics. In the tyrosinase inhibition and 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assays, two fungal extracts, including “P2”, Talaromyces stipitatus and “D4”, Aspergillus terreus showed high inhibitory activity at 1mg/mL for tyrosinase inhibition and 0.5mg/mL for DPPH scavenging. The in vitro antimicrobial activity was investigated by the agar well diffusion method. In the tyrosinase inhibition assay, 8 extracts showed significant antibacterial activity against bacteria causing skin and wound infection in humans. In the course of systematic screening program for bioactive marine fungi, strain “D5” was found to be most potent strain with MIC value of 1mg/mL, which was morphologically identified as Simplicillium lamellicola. The effects of the most active crude extracts against their susceptible test microorganisms were also investigated by SEM analysis. Further investigations will focus on purification and characterization major active components responsible for these activities.

Keywords: antioxidant, antimicrobial activity, tyrosinase, cosmeceuticals, marine fungi

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Authors: Ravinder Singh, Ankita Gurao, Saroj Bandhan, Sudhir Kumar Kashyap

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The Bos taurus Beta defensin 3 is a defensin peptide secreted by neutrophils and epithelial that exhibits anti-microbial activity. It is one of the crucial components forming an innate defense against intra mammary infections in livestock. The beta defensin 3 by virtue of its anti-microbial activity inhibits major mastitis pathogens including Staphylococcus aureus and Pseudomonas aeruginosa etc, which are also responsible for biofilm formation leading to antibiotic resistance phenomenon. Therefore, the defensin may prove as a non-conventional option to treat mastitis. In this study, computational analysis has been performed including sequence comparison among species and homology modeling of Bos taurus beta defensin 3 protein. The assessments of protein structure were done using the protein structure and model assessment tools integrated in Swiss Model server, which employs various local and global quality evaluation parameters. Further, molecular docking was also carried out between the defensin peptide and the components of biofilm to gain insight into various interactions and structural differences crucial for functionality of this protein.

Keywords: beta defensin 3, bos taurus, docking, homology modeling

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Authors: Shiv Mohan Singh, Gwyneth Matcher

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To understand the culturable microbial composition and diversity patterns, soil samples were collected from inland nunataks of Jutulsessen and Ahlmannryggen ranges in Dronning Maud Land, Antarctica. 16S rRNA, ITS and the D1/D2 domain sequencing techniques were used for characterization of microbial communities of these geographical areas. The total 37 species of bacteria such as Arthrobacter agilis, Acinetobacter baumannii, Arthrobacter flavus, Arthrobacter ginsengisoli, Arthrobacter oxydans, Arthrobacter oryzae, Arthrobacter polychromogenes, Arthrobacter sulfonivorans, Bacillus altitudinis, Bacillus cereus, Bacillus paramycoides, Brevundimonas vesicularis, Brachybacterium rhamnosum, Curtobacterium luteum, Dermacoccus nishinomiyaensis, Dietzia aerolata, Janibacter indicus, Knoellia subterranean, Kocuria palustris, Kytococcus aerolatus, Lysinibacillus sphaericus, Microbacterium phyllosphaerae, Micrococcus yunnanensis, Methylobacterium rhodesianum, Moraxella osloensis, Paracoccus acridae, Pontibacter amylolyticus, Pseudomonas hunanensis, Pseudarthrobacter siccitolerans, Pseudarthrobacter phenanthrenivorans, Rhodococcus aerolatus, Rhodococcus sovatensis, Sphingomonas daechungensis, Sphingomonas sanguinis, Stenotrophomonas pavanii, Staphylococcus gallinarum, Staphylococcus arlettae and 9 species of fungi such as Candida davisiana, Cosmospora arxii, Geomyces destructans, Lecanicillium muscarium, Memnoniella humicola, Paecilomyces lilacinus, Pseudogymnoascus verrucosus, Phaeophlebiopsis ignerii and Thyronectria caraganae were recorded. Fatty acid methyl esters (FAME) analyses of representative species of each genus have shown predominance branched and unsaturated fatty acids indicate its adaptation strategy in Antarctic cold environment. To the best of our knowledge, this is the first record of culturable bacterial communities from Jutulsessen and Ahlmannryggen ranges in Western Dronning Maud Land, Antarctica.

Keywords: antarctica, microbe, adaptation, polar

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Authors: Mabtho Moreroa-Monyelo, Grace Ijoma, Rosina Nkuna, Tonderayi Matambo

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A moving bed biofilm reactor (MBBR) was used for the bioremediation of high strength chemical oxygen demand (COD) Fisher-Tropsch (FT) wastewater. The aerobic MBBR system was operated over 60 days. For metagenomics profile assessment of the targeted 16S sequence of bacteria involved in the bioremediation of the chemical compounds, sludge samples were collected every second day of operation. Parameters such as pH and COD were measured daily to compare the system efficiency as the changedin microbial diversity progressed. The study revealed that pH was a contributing factor to microbial diversity, which further affected the efficiency of the MBBR system. The highest COD removal rate of 86.4% was achieved at pH 8.3. It was observed that when there was more, A higher bacterial diversity led to an improvement in the reduction of COD. Furthermore, an OTUof 4530 was obtained, which were divided into 12 phyla, 27 classes, 44 orders, 74 families, and 138 genera across all sludge samples from the MBBR. A determination of the relative abundance of microorganisms at phyla level indicates that the most abundant phylum on day it was Firmicutes (50%); thereafter, the most abundant phylum changed toProteobacteria.

Keywords: biodegradation, fischer-tropsch wastewater, metagenomics, moving bed biofilm reactor

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Authors: Reda A. Elkhyat, Mahmoud Nasr, Amel A. Tammam, Mohamed A. Ghazy

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Pharmaceuticals and personal care products (PPCPs) are a unique group of emerging contaminants continuously introduced into the aquatic ecosystem at concentrations capable of inducing adverse effects on humans and aquatic organisms, even at trace levels ranging from ppt to ppm. Amongst the common pharmaceutical emerging pollutants detected in several aquatic environments, acetaminophen has been recognized for its high toxicity. Once released into the aquatic environment, acetaminophen could be degraded by the microbial community and adsorption/ uptake by the plants. Although many studies have investigated the hazard risks of acetaminophen pollutants on aquatic animals, the number of studies demonstrating its removal efficiency and effects on the aquatic plant still needs to be expanded. In this context, this study aims to apply the aquatic plant-based phytoremediation system to eliminate this emerging contaminant from domestic wastewater. The phytoremediation experiment was performed in a hydroponic system containing Eichhornia crassipes and operated under the natural environment at 25°C to 30°C. This system was subjected to synthetic domestic wastewater with the maximum initial chemical oxygen demand (COD) of 390 mg/L and three different acetaminophen concentrations of 25, 50, and 200 mg/L. After 17 d of operation, the phytoremediation system achieved removal efficiencies of about 100% and 85.6±4.2% for acetaminophen and COD, respectively.Moreover, the Eichhornia crassipes could withstand the toxicity associated with increasing the acetaminophen concentrations from 25 to 200 mg/L. This high treatment performance could be assigned to the well-adaptation of the water hyacinth to the phytoremediation factors. Moreover, it has been proposed that this phytoremediation system could be largely supported by phytodegradation and plant uptaking mechanisms; however, detecting the generated intermediates, metabolites, and degradation products are still under investigation. Applying this free-floating plant in wastewater treatment and reducing emerging contaminants would meet the targets of SDGs 3, 6, and. 14. The cost-benefit analysis was performed for the phytoremediation system. The phytoremediation system is financially viable as the net profit was 2921 US $/ y with a payback period of nine years.

Keywords: domestic wastewater, emerging pollutants, hydrophyte Eichhornia crassipes, paracetamol removal efficiency, sustainable development goals (SDGs)

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Authors: A. Monika, Manu Sharma, Hong Boo Lee, Richa Dhingra, Neelima Dhingra

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Nuclear factor-κappa B serve as a molecular lynchpin that links persistent infections and chronic inflammation to increased cancer risk. Inflammation has been recognized as a hallmark and cause of cancer. Natural products present a privileged source of inspiration for chemical probe and drug design. Herbal remedies were the first medicines used by humans due to the many pharmacologically active secondary metabolites produced by plants. Some of the metabolites like Lantadene (pentacyclic triterpenoids) from the weed Lantana camara has been known to inhibit cell division and showed anti-antitumor potential. The C-3 aromatic esters of lantadenes were synthesized, characterized and evaluated for cytotoxicity and inhibitory potential against Tumor necrosis factor alpha-induced activation of Nuclear factor-κappa B in lung cancer cell line A549. The 3-methoxybenzoyloxy substituted lead analogue inhibited kinase activity of the inhibitor of nuclear factor-kappa B kinase in a single-digit micromolar concentration. At the same time, the lead compound showed promising cytotoxicity against A549 lung cancer cells with IC50 ( half maximal inhibitory concentration) of 0.98l µM. Further, molecular docking of 3-methoxybenzoyloxy substituted analogue against Inhibitor of nuclear factor-kappa B kinase (Protein data bank ID: 3QA8) showed hydrogen bonding interaction involving oxygen atom of 3-methoxybenzoyloxy with the Arginine-31 and Glutamine-110. Encouraging results indicate the Lantadene’s potential to be developed as anticancer agents.

Keywords: anticancer, lantadenes, pentacyclic triterpenoids, weed

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Authors: Boonsiri Dandumrongsin, Halis Simsek, Chaiwat Rongsayamanont

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Dissolved organic nitrogen (DON) is known as one of the persistence nitrogenous pollutant being originated from secondary treated effluent of municipal sewage treatment plant. However, effect of key system operating condition on the fate and behavior of residual DON in the treated effluent is still not known. This study aims to investigate effect of organic loading rate (OLR) on the residual level of DON in the biofilm reactor effluent. Synthetic municipal wastewater was fed into moving bed biofilm reactors at OLR of 1.6x10-3 and 3.2x10-3 kg SCOD/m3-d. The results showed higher organic removal efficiency was found in the reactor operating at higher OLR. However, DON was observed at higher value in the effluent of the higher OLR reactor than that of the lower OLR reactor evidencing a clear influence of OLR on the residual DON level in the treated effluent of the biofilm reactors. It is possible that the lower DON being observed in the reactor at lower OLR is likely to be a result of providing the microbe with the additional period for utilizing the refractory DON molecules during operation at lower organic loading. All the experiments were repeated using raw wastewaters and similar trend was obtained.

Keywords: dissolved organic nitrogen, hydraulic retention time, moving bed biofilm reactor, soluble microbial products

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Authors: Yogesh Bacchaw, Ashish Dabade

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Nowadays oral health is raising concern in society. Acid producing microorganisms changes the oral pH and creates a favorable environment for microbial growth. This growth not only promotes dental decay but also bad breath. Generally Recognized As Safe (GRAS) listed component was incorporated in chewing gum as an antimicrobial agent. The chewing gum produced exhibited up to 9 hours of antimicrobial activity against oral microflora. The toxicity of GRAS component per RACC value of chewing gum was negligible as compared to actual toxicity level of GRAS component. The antibacterial efficiency of chewing gum was tested by using total plate count (TPC) and colony forming unit (CFU). Nine hours were required to microflora to reach TPC/CFU of before chewing gum consumption. This chewing gum not only provides mouth freshening activity but also helps in lowering dental decay, bad breath, and enamel whitening.

Keywords: colony forming unit (CFU), chewing gum, generally recognized as safe (GRAS), microbial growth, microorganisms, oral health, RACC, total plate count (TPC), antimicrobial agent, enamel whitening, oral pH

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Authors: Tuji Jemal Ahmed

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Fresh produce is an essential component of a healthy diet. However, it can also be a potential source of pathogenic microorganisms that can cause foodborne illnesses. Traditional disinfection methods, such as washing with water and chlorine, have limitations and may not effectively remove or inactivate all microorganisms. This has led to the development of alternative/new methods of fresh produce disinfection, including physical and chemical methods. In this paper, we explore the physical and chemical new methods of fresh produce disinfection, their advantages and disadvantages, and their suitability for different types of produce. Physical methods of disinfection, such as ultraviolet (UV) radiation and high-pressure processing (HPP), are crucial in ensuring the microbiological safety of fresh produce. UV radiation uses short-wavelength UV-C light to damage the DNA and RNA of microorganisms, and HPP applies high levels of pressure to fresh produce to reduce the microbial load. These physical methods are highly effective in killing a wide range of microorganisms, including bacteria, viruses, and fungi. However, they may not penetrate deep enough into the product to kill all microorganisms and can alter the sensory characteristics of the product. Chemical methods of disinfection, such as acidic electrolyzed water (AEW), ozone, and peroxyacetic acid (PAA), are also important in ensuring the microbiological safety of fresh produce. AEW uses a low concentration of hypochlorous acid and a high concentration of hydrogen ions to inactivate microorganisms, ozone uses ozone gas to damage the cell membranes and DNA of microorganisms, and PAA uses a combination of hydrogen peroxide and acetic acid to inactivate microorganisms. These chemical methods are highly effective in killing a wide range of microorganisms, but they may cause discoloration or changes in the texture and flavor of some products and may require specialized equipment and trained personnel to produce and apply. In conclusion, the selection of the most suitable method of fresh produce disinfection should take into consideration the type of product, the level of microbial contamination, the effectiveness of the method in reducing the microbial load, and any potential negative impacts on the sensory characteristics, nutritional composition, and safety of the produce.

Keywords: fresh produce, pathogenic microorganisms, foodborne illnesses, disinfection methods

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Authors: Nneka Augustina Akwu, Yougasphree Naidoo

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Molecular advancement in technology has created a means whereby the atoms and molecules (solid forms) of certain materials such as plants, can now be reduced to a range of 1-100 nanometres. Green synthesis of silver nanoparticles (AgNPs) was carried out at room temperature (RT) 25 ± 2°C and 80°C, using the metabolites in the aqueous extracts of the leaves and stem bark of Grewia lasiocarpa as reductants and stabilizing agents. The biosynthesized AgNPs were characterized by UV-Vis spectrophotometry, attenuated total reflectance - Fourier transforms infrared (ATR-FTIR) spectroscopy, nanoparticle tracking analysis (NTA), Energy Dispersive X-ray fluorescence scanning electron microscope (SEM-EDXRF) and high-resolution transmission electron microscopy (HRTEM). The AgNPs were biologically evaluated for antioxidant, antibacterial and cytotoxicity activities. The phytochemical and FTIR analyses revealed the presence of metabolites that act as reducing and capping agents, while the UV-Vis spectroscopy of the biosynthesized NPs showed absorption between 380-460 nm, confirming AgNP synthesis. The Zeta potential values were between -9.1 and -20.6 mV with a hydrodynamics diameter ranging from 38.3 to 46.7 nm. SEM and HRTEM analyses revealed that AgNPs were predominately spherical with an average particle size of 2- 31 nm for the leaves and 5-27 nm for the stem bark. The cytotoxicity IC50 values of the AgNPs against HeLa, Caco-2 and MCF-7 were >1 mg/mL. The AgNPs were sensitive to all strains of bacteria used, with methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) being more sensitive to the AgNPs. Our findings propose that antibacterial and anticancer agents could be derived from these AgNPs of G. lasiocarpa, and warrant their further investigation.

Keywords: antioxidant, cytotoxicity, Grewia lasiocarpa, silver nanoparticles, Zeta potentials

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Authors: Bensaid Fatiha

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The objective of our present work is the description of the antagonistic capacities of one strain of Pseudomonas fluorescens and the nonpathogenic fungic isolate Fusarium oxysporum against phytopathogenic agent Fusarium oxysporum F. Sp. lycopersici. This work has been achieved in two main parts: the first is interested on the in vitro antagonistic activities; the second was interested to study the soil receptiveness of fusarium wilt tomato. The use of strain of fluorescent Pseudomonas and a non-pathogenic strain of F. oxysporum in the different antagonism tests, has allowed assuring a certain bio-protection from the plants of tomatoes opposite to F. oxysporum F. Sp. lycopersici, agent of a wilt of tomato. These antagonistic have shown a substantial in vitro antagonistic activity on the three mediums (KB, PDA, KB+PDA) against F. oxysporum F. Sp. lycopersici, by inhibiting its growth mycelium with rate of inhibition going until 80 % with non-pathogen of Fusarium oxysporum and 60 % with strain of fluorescens Pseudomonas. Soil microbial balance, between the antagonistic population and that of pathogenic, can be modulated through microbiological variations or abiotic additives influencing directly or indirectly the metabolic behavior microbial. In this experiment, addition of glucose or EDTA, could increase or decrease the resistance of soil by activation of pathogenic or antagonists, as a result of modification and modulation in their metabolic activities.

Keywords: fluorescents, nonpathogenic, fusarium oxysporum, fusarium wilt, antagonism, biological control, soil receptivity

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Authors: Patricia M. B. Saint-Vincent, Anna Furches, Stephanie Galanie, Erica Teixeira Prates, Piet Jones, Nancy Engle, David Kainer, Wellington Muchero, Daniel Jacobson, Timothy J. Tschaplinski

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Uridine diphosphate-glycosyltransferases (UGTs) are enzymes that catalyze sugar transfer to a variety of plant metabolites. UGT substrates, which include plant secondary metabolites involved in lignification, demonstrate new activities and incorporation when glycosylated. Knowledge of UGT function, substrate specificity, and enzyme products is important for plant engineering efforts, especially related to increasing plant biomass through lignification. UGTs in Populus trichocarpa, a biofuel feedstock, and model woody plant, were selected from a pool of gene candidates using rapid prioritization strategies. A functional genomics workflow, consisting of a metabolite genome-wide association study (mGWAS), expression of synthetic codon-optimized genes, and high-throughput biochemical assays with mass spectrometry-based analysis, was developed for determining the substrates and products of previously-uncharacterized enzymes. A total of 40 UGTs from P. trichocarpa were profiled, and the biochemical assay results were compared to predicted mGWAS connections. Assay results confirmed seven of 11 leaf mGWAS associations and demonstrated varying levels of substrate specificity among candidate UGTs. P. trichocarpa UGT substrate processing confirms the role of these newly-characterized enzymes in lignan, flavonoid, and phytohormone metabolism, with potential implications for cell wall biosynthesis, nitrogen uptake, and biotic and abiotic stress responses.

Keywords: Populus, metabolite-gene associations, GWAS, bio feedstocks, glycosyltransferase

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Authors: Bisi-Johnson, Mary A., Hamzart A. Oyelade, Kehinde A. Adediran, Saheed A. Akinola

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Geophagic and cosmetic clays are among potential nano-material which occur naturally and are of various forms. The use of these nano-clays is a common practice in both rural and urban areas mostly due to tradition and medicinal reasons. These naturally occurring materials can be valuable sources of nano-material by serving as nano-composites. The need to ascertain the safety of these materials is the motivation for this research. Physical Characterization based on the hue value and microbiological qualities of the nano-clays were carried out. The Microbial analysis of the clay samples showed considerable contamination with both bacteria and fungi with fungal contaminants taking the lead. This observation may not be unlikely due to the ability of fungi species to survive harsher growth conditions than bacteria. 'Atike pupa' showed no bacterial growth. The clay with the largest bacterial count was Calabash chalk (Igbanke), while that with the highest fungal count was 'Eko grey'. The most commonly isolated bacteria in this study were Clostridium spp. and Corynebacterium spp. while fungi included Aspergillus spp. These results are an indication of the need to subject these clay materials to treatments such as heating before consumption or topical usage thereby ascertaining their safety.

Keywords: nano-material, clay, microorganism, quality

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Authors: D. Motlhanka, M. Mine, T. Bagaketse, T. Ngakane

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There is a plethora of evidence from numerous sources that highlights the triumph of naturally derived medicinal plant metabolites with antioxidant capability for repurposed therapeutics. As post-COVID-19 syndromes and non-communicable diseases are on the rise, there is an urgent need to come up with new therapeutic strategies to address the problem. Non-communicable diseases and Post COVID-19 syndromes are classified as socio-economic diseases and are ranked high among threats to health security due to the economic burden they pose to any government budget commitment. Research has shown a strong link between accumulation of free radicals and oxidative stress critical for pathogenesis of non-communicable diseases and COVID-19 syndromes. Botswana has embarked on a robust programme derived from ethno-pharmacognosy and drug repurposing to address these threats to health security. In the current approach, a number of medicinally active plant-derived polyphenolics are repurposed and combined into new medicinal tools to target diabetes, Hypertension, Prostate Cancer and oxidative stress induced Post COVID 19 syndromes such as “brain fog”. All four formulants demonstrated Free Radical scavenging capacities above 95% at 200µg/ml using the diphenylpicryalhydrazyl free radical scavenging assay and the total phenolic contents between 6899-15000GAE(g/L) using the folin-ciocalteau assay respectively. These repurposed medicinal tools offer new hope and potential in the fight against emerging health threats driven by hyper-inflammation and free radical-induced oxidative stress.

Keywords: drug repurposed plant polyphenolics, free radical damage, non-communicable diseases, post COVID 19 syndromes

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Authors: Ravi Prakash Maurya, Munaswamyreddygari Sreedhar

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The present studies on ecological engineering through soil amendments in cabbage crops for insect pests regulation were conducted at G. B. Pant University of Agriculture and Technology, Pantnagar, Udham Singh Nagar, Uttarakhand, India. Ten treatments viz., Farm Yard Manure (FYM), Neem cake (NC), Vermicompost (VC), Poultry manure (PM), PM+FYM, NC+VC, NC+PM, VC+FYM, Urea+ SSP+MOP (Standard Check) and Untreated Check were evaluated to study the effect of these amendments on the population of insect pests, natural enemies and the microbial community of the rhizosphere in the cabbage crop ecosystem. The results revealed that most of the cabbage pests, viz., aphids, head borer, gram pod borer, and armyworm, were more prevalent in FYM, followed by PM and NC-treated plots. The best cost-benefit ratio was found in PM + FYM treatment, which was 1: 3.62, while the lowest, 1: 0.97, was found in the VC plot. The population of natural enemies like spiders, coccinellids, syrphids, and other hymenopterans and dipterans was also found to be prominent in organic plots, namely FYM, followed by VC and PM plots. Diversity studies on organic manure-treated plots were also carried out, which revealed a total of nine insect orders (Hymenoptera, Hemiptera, Lepidoptera, Coleoptera, Neuroptera, Diptera, Orthoptera, Dermaptera, Thysanoptera, and one arthropodan class, Arachnida) in different treatments. The Simpson Diversity Index was also studied and found to be maximum in FYM plots. The metagenomic analysis of the rhizosphere microbial community revealed that the highest bacterial count was found in NC+PM plot as compared to standard check and untreated check. The diverse microbial population contributes to soil aggregation and stability. Healthier soil structures can improve water retention, aeration, and root penetration, which are all crucial for crop health. The further analysis also identified a total of 39 bacterial phyla, among which the most abundant were Actinobacteria, Firmicutes, and the SAR324 clade. Actinobacteria and Firmicutes are known for their roles in decomposing organic matter and mineralizing nutrients. Their highest abundance suggests improved nutrient cycling and availability, which can directly enhance plant growth. Hence, organic amendments in cabbage farming can transform the rhizosphere microbiome, reduce pest pressure, and foster populations of beneficial insects, leading to healthier crops and a more sustainable agricultural ecosystem.

Keywords: cabbage ecosystem, organic amendments, rhizosphere microbiome, pest and natural enemy diversity

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Authors: S. Taghavi Kalajahi, A. Koerdt, T. Lund Skovhus

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Cathodic protection (CP) is an electrochemical method to control and manage corrosion in different industries and environments. CP which is widely used, especially in buried and sub-merged environments, which both environments are susceptible to microbiologically influenced corrosion (MIC). Most of the standards recommend performing CP using -800 mV, however, if MIC threats are high or sulfate reducing bacteria (SRB) is present, the recommendation is to use more negative potentials for adequate protection of the metal. Due to the lack of knowledge and research on the effectiveness of CP on MIC, to the author’s best knowledge, there is no information about what MIC threat is and how much more negative potentials should be used enabling adequate protection and not overprotection (due to hydrogen embrittlement risk). Recently, the development and cheaper price of molecular microbial methods (MMMs) open the door for more effective investigations on the corrosion in the presence of microorganisms, along with other electrochemical methods and surface analysis. In this work, using MMMs, the gene expression of SRB biofilm under different potentials of CP will be investigated. The specific genes, such as pH buffering, metal oxidizing, etc., will be compared at different potentials, enabling to determine the precise potential that protect the metal effectively from SRB. This work is the initial step to be able to standardize the recommended potential under MIC condition, resulting better protection for the infrastructures.

Keywords: cathodic protection, microbiologically influenced corrosion, molecular microbial methods, sulfate reducing bacteria

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Authors: Lohendy Munoz-Vargas, Stephen O. Opiyo, Rose Digianantonio, Michele L. Williams, Asela Wijeratne, Gregory Habing

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Non-typhoidal Salmonella enterica is a zoonotic pathogen with critical importance in animal and public health. The persistence of Salmonella on farms affects animal productivity and health, and represents a risk for food safety. The intestinal microbiota plays a fundamental role in the colonization and invasion of this ubiquitous microorganism. To overcome the colonization resistance imparted by the gut microbiome, Salmonella uses invasion strategies and the host inflammatory response to survive, proliferate, and establish infections with diverse clinical manifestations. Cattle serve as reservoirs of Salmonella, and periparturient cows have high prevalence of Salmonella shedding; however, to author`s best knowledge, little is known about the association between the gut microbiome and the onset of Salmonella shedding during the periparturient period. Thus, the objective of this study was to assess the association between changes in bacterial communities and the onset of Salmonella shedding in cattle approaching parturition. In a prospective cohort study, fecal samples from 98 dairy cows originating from four different farms were collected at four time points relative to calving (-3 wks, -1 wk, +1 wk, +3 wks). All 392 samples were cultured for Salmonella. Sequencing of the V4 region of the 16S rRNA gene using the Illumina platform was completed to evaluate the fecal microbiome in a selected sample subset. Analyses of microbial composition, diversity, and structure were performed according to time points, farm, and Salmonella onset status. Individual cow fecal microbiomes, predominated by Bacteroidetes, Firmicutes, Spirochaetes, and Proteobacteria phyla, significantly changed before and after parturition. Microbial communities from different farms were distinguishable based on multivariate analysis. Although there were significant differences in some bacterial taxa between Salmonella positive and negative samples, our results did not identify differences in the fecal microbial diversity or structure for cows with and without the onset of Salmonella shedding. These data suggest that determinants other than the significant changes in the fecal microbiome influence the periparturient onset of Salmonella shedding in dairy cattle.

Keywords: dairy cattle, microbiome, periparturient, Salmonella

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Authors: Feiyu Yang, Chunfang Ni, Rong Wang, Yun Zou, Wenbin Liu, Chenggong Zhang, Fenjin Sun, Chun Wang

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Cocaine is the most frequently used illegal drug globally, with the global annual prevalence of cocaine used ranging from 0.3% to 0.4 % of the adult population aged 15–64 years. Growing consumption trend of abused cocaine and drug crimes are a great concern, therefore urine sample testing has become an important noninvasive sampling whereas cocaine and its metabolites (COCs) are usually present in high concentrations and relatively long detection windows. However, direct analysis of urine samples is not feasible because urine complex medium often causes low sensitivity and selectivity of the determination. On the other hand, presence of low doses of analytes in urine makes an extraction and pretreatment step important before determination. Especially, in gathered taking drug cases, the pretreatment step becomes more tedious and time-consuming. So developing a sensitive, rapid and high-throughput method for detection of COCs in human body is indispensable for law enforcement officers, treatment specialists and health officials. In this work, a new automated magnetic dispersive solid-phase extraction (MDSPE) sampling method followed by high performance liquid chromatography-mass spectrometry (HPLC-MS) was developed for quantitative enrichment of COCs from human urine, using prepared magnetic nanoparticles as absorbants. The nanoparticles were prepared by silanizing magnetic Fe3O4 nanoparticles and modifying them with divinyl benzene and vinyl pyrrolidone, which possesses the ability for specific adsorption of COCs. And this kind of magnetic particle facilitated the pretreatment steps by electromagnetically controlled extraction to achieve full automation. The proposed device significantly improved the sampling preparation efficiency with 32 samples in one batch within 40mins. Optimization of the preparation procedure for the magnetic nanoparticles was explored and the performances of magnetic nanoparticles were characterized by scanning electron microscopy, vibrating sample magnetometer and infrared spectra measurements. Several analytical experimental parameters were studied, including amount of particles, adsorption time, elution solvent, extraction and desorption kinetics, and the verification of the proposed method was accomplished. The limits of detection for the cocaine and cocaine metabolites were 0.09-1.1 ng·mL-1 with recoveries ranging from 75.1 to 105.7%. Compared to traditional sampling method, this method is time-saving and environmentally friendly. It was confirmed that the proposed automated method was a kind of highly effective way for the trace cocaine and cocaine metabolites analyses in human urine.

Keywords: automatic magnetic dispersive solid-phase extraction, cocaine detection, magnetic nanoparticles, urine sample testing

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Authors: Zohreh Rashmei

Abstract:

Introduction: Plasma inactivation is one of the emerging technologies in biomedical field and has been applied to the inactivation of microorganisms in water. The inactivation effect has been attributed to the presence of active plasma species, i.e. OH, O, O3, H2O2, UV and electric fields, generated by the discharge of plasma. Material and Method: To evaluate germicidal effects of plasma, the electric spark discharge device was used. After the effect of the plasma samples were collected for culture medium agar plate count. In addition to biological experiments, the concentration of hydrogen peroxide was also measured. Results: The results showed that Plasma is able to inactivate a high concentration of E. coli. After a short period of plasma radiation on the surface of water, the amount log8 reduced the microbial load. Starting plasma radiation on the surface of the water, the measurements show of production and increasing the amount of hydrogen peroxide in water. So that at the end of the experiment, the concentration of hydrogen peroxide to about 100 mg / l increased. Conclusion: Increasing the concentration of hydrogen peroxide is directly related to the reduction of microbial load. The results of E. coli culture in media containing certain concentrations of H2O2 showed that E. coli can not to grow in a medium containing more than 2/5 mg/l of H2O2. Surely we can say that the main cause of killing bacteria is a molecule of H2O2.

Keywords: plasma, hydrogen peroxide, disinfection, E. coli

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