Search results for: microbial inactivation

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

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Aim: Aim of this study was to evaluate the reduction on Intensive Care Unit (ICU) microbial flora after the antimicrobial copper alloy (Cu+) implementation as well as the effect on financial-epidemiological operation parameters. Methods: Medical, epidemiological and financial data in two time periods, before and after the implementation of copper (Cu 63% - Zn 37%, low lead) were recorded and analyzed in a general ICU. The evaluated parameters were: the importance of patients' admission (Acute Physiology and Chronic Health Evaluation - APACHE II and Simplified Acute Physiology Score - SAPS), microbial flora's record in the ICU before and after the implementation of Cu+ as well as the impact on epidemiological and ICU's operation financial parameters. Results: During December 2010 and March 2011 and respectively during December 2011 and March 2012 comparative results showed statistically significant reduction on the microbial flora (CFU/ml) by 95% and the use of antimicrobial medicine (per day per patient) by 30% (p = 0,014) as well as patients hospitalization time and cost. Conclusions: The innovative implementation of antimicrobial copper in ICUs contributed to their microbial flora significant reduction and antimicrobial drugs use reduction with the apparent positive effect (decrease) in both patient’s hospitalization time and cost. Under the present circumstances of economic crisis, survey results are of highest importance and value.

Keywords: antimicrobial copper, financial benefits, ICU, cost reduction

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Authors: Maria Luiza D. Ramiento, Maria Lissette D. Lucas

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Electricity is said to serve as the backbone of modern technology. Considering this, electricity consumption has dynamically grown due to the continuous demand. An alternative producer of energy concerning electricity must therefore be given focus. Microbial fuel cell wholly characterizes a new method of renewable energy recovery: the direct conversion of organic matter to electricity using bacteria. Electricity is produced as fuel or new food is given to the bacteria. The study concentrated in determining the feasibility of electricity production from local benthic zones. Microbial fuel cells were constructed to harvest the possible electricity and to test the presence of electricity producing microorganisms. Soil samples were gathered from Calumpang River, Palawan Mangrove Forest, Rosario River and Batangas Port. Eleven modules were constructed for the different trials of the soil samples. These modules were made of cathode and anode chambers connected by a salt bridge. For 85 days, the harvested voltage was measured daily. No parameter is added for the first 24 days. For the next 61 days, acetic acid was included in the first and second trials of the modules. Each of the trials of the soil samples gave a positive result in electricity production.There were electricity producing microbes in local benthic zones. It is observed that the higher the organic content of the soil sample, the higher the electricity harvested from it. It is recommended to identify the specific species of the electricity-producing microorganism present in the local benthic zone. Complement experiments are encouraged like determining the kind of soil particles to test its effect on the amount electricity that can be harvested. To pursue the development of microbial fuel cells by building a closed circuit in it is also suggested.

Keywords: microbial fuel cell, benthic zone, electricity, reduction-oxidation reaction, bacteria

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Authors: Jannika Dombrowski, Sabine Ambros, Ulrich Kulozik

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Several drying techniques are used to preserve sensitive substances such as probiotic lactic acid bacteria. With the aim to better understand differences between these processes, this work gives new insights into structural variations resulting from different preservation methods and their impact on product quality and storage stability. Industrially established methods (freeze drying, spray drying) were compared to upcoming vacuum, microwave-freeze, and microwave-vacuum drying. For freeze and microwave-freeze dried samples, survival and activity maintained 100%, whereas vacuum and microwave-vacuum dried cultures achieved 30-40% survival. Spray drying yielded in lowest viability. The results are directly related to temperature and oxygen content during drying. Interestingly, most storage stable products resulted from vacuum and microwave-vacuum drying due to denser product structures as determined by helium pycnometry and SEM images. Further, lower water adsorption velocities were responsible for lower inactivation rates. Concluding, resulting product structures as well as survival rates and storage stability mainly depend on the type of water removal instead of energy input. Microwave energy compared to conductive heating did not lead to significant differences regarding the examined factors. Correlations could be proven for three investigated microbial strains. The presentation will be completed by an overview on the energy efficiency of the presented methods.

Keywords: drying techniques, energy efficiency, lactic acid bacteria, probiotics, survival rates, structure characterization

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Authors: Ali Haratian, Soroosh Emami Meybodi

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Using viable microbial cultures within hydrocarbon reservoirs so as to the enhancement of oil recovery through metabolic activities is exactly what we recognize as microbial enhanced oil recovery (MEOR). In similar to many other processes in industries, there are some cons and pros following with MEOR. The creation of sulfides such as hydrogen sulfide as a result of injecting the sulfate-containing seawater into hydrocarbon reservoirs in order to maintain the required reservoir pressure leads to production and growth of sulfate reducing bacteria (SRB) approximately near the injection wells, turning the reservoir into sour; however, SRB is not considered as the only microbial process stimulating the formation of sulfides. Along with SRB, thermochemical sulfate reduction or thermal redox reaction (TSR) is also known to be highly effective at resulting in having extremely concentrated zones of ?2S in the reservoir fluids eligible to cause corrosion. Owing to extent of the topic, more information on the formation of ?₂S is going to be put finger on. Besides, confronting the undesirable production of sulfide species in the reservoirs can lead to serious operational, environmental, and financial problems, in particular the transporting pipelines. Consequently, conjuring up reservoir souring control strategies on the way production of oil and gas is the only way to prevent possible damages in terms of environment, finance, and manpower which requires determining the compound’s reactivity, origin, and partitioning behavior. This article is going to provide a comprehensive review of progress made in this field and the possible advent of new strategies in this technologically advanced world of the petroleum industry.

Keywords: corrosion, hydrogen sulfide, NRB, reservoir souring, SRB

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Authors: Klementina Puto, Ermelinda Nexhipi, Evi Llaka

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Dairy by-products are a fairly good environment for microorganisms due to their composition for their growth. Microbial populations have a significant impact in the production of cheese, butter, yogurt, etc. in terms of their organoleptic quality and at the same time some also cause their breakdown. In this paper, the microbiological contamination of soft cheese, butter and yogurt produced in the country (domestic) and imported is assessed, as an indicator of hygiene with impact on public health. The study was extended during September 2018-June 2019 and was divided into three periods, September-December, January-March, and April-June. During this study, a total of 120 samples were analyzed, of which 60 samples of cheese and butter locally produced, and 60 samples of imported soft cheese and butter productions. The microbial indicators analyzed are Staphylococcus aureus and E. coli. Analyzes have been conducted at the Food Safety Laboratory (FSIV) in Tirana in accordance with EU Regulation 2073/2005. Sampling was performed according to the specific international standards for these products (ISO 6887 and ISO 8261). Sampling and transport of samples were done under sterile conditions. Also, coding of samples was done to preserve the anonymity of subjects. After the analysis, the country's soft cheese products compared to imports were more contaminated with S. aureus and E. coli. Meanwhile, the imported butter samples that were analyzed, resulted within norms compared to domestic ones. Based on the results, it was concluded that the microbial quality of samples of cheese, butter and yogurt analyzed remains a real problem for hygiene in Albania. The study will also serve business operators in Albania to improve their work to ensure good hygiene on the basis of the HACCP plan and to provide a guarantee of consumer health.

Keywords: consumer, health, dairy, by-products, microbial

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Authors: Somaye Eskandary

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Polycyclic aromatic hydrocarbons (PAHs) are present in crude oil and its derivatives contaminate soil and also increase carcinogen and mutagen contamination, which is a concern for researchers. Land farming is one of the methods that remove pollutants from the soil by native microorganisms. It seems that this technology is cost-effective, environmentally friendly and causes less debris problem to be disposed. This study aimed to refine the polycyclic aromatic hydrocarbons from oil-contaminated soil using the land farming method. In addition to examine the concentration of polycyclic aromatic hydrocarbons by GC-FID, some characteristics such as soil microbial respiration and dehydrogenase, peroxidase, urease, acid and alkaline phosphatase enzyme concentration were also measured. The results showed that after land farming process the concentrations of some polycyclic aromatic hydrocarbons dropped to 50 percent. The results showed that the enzyme concentration is reduced by reducing the concentration of hydrocarbons and microbial respiration. These results emphasize the process of land farming for removal of polycyclic aromatic hydrocarbons from soil by indigenous microorganisms.

Keywords: soil contamination, gas chromatography, native microorganisms, soil enzymes, microbial respiration, carcinogen

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Authors: Pei-Lin Yueh, Bor-Yann Chen, Chuan-Chung Hsueh

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This first-attempt study revealed that decolorized intermediates of azo dyes could act as redox mediators to assist wastewater (WW) decolorization due to enhancement of electron-transport phenomena. Electrochemical impedance spectra indicated that hydroxyl and amino-substituent(s) were functional group(s) as redox-mediator(s). As azo dyes are usually multiple benzene rings structured, their derived decolorized intermediates are likely to play roles of electron shuttles due to lower barrier of energy gap for electron shuttling. According to cyclic voltammetric profiles, redox-mediating characteristics of decolorized intermediates of azo dyes (e.g., RBu171, RR198, RR141, and RBk5) were clearly disclosed. With supplementation of biodecolorized metabolites of RR141 and 198, decolorization performance of could be evidently augmented. This study also suggested the optimal modes of microbial fuel cell (MFC)-assisted WW decolorization would be plug-flow or batch mode of operation with no mix. Single chamber-MFCs would be more favourable than double chamber MFCs due to non-mixing contacting reactor scheme for operation.

Keywords: redox mediators, dye decolorization, bioelectricity generation, microbial fuel cells

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Authors: Nurhajati Hakim, Kiki Amalia, A. Agustian, H. Hermansah, Y. Yulnafatmawita

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Ultisols require greater amounts of fertilizer application compared to other soils and susceptible to erosion. Unfortunately, the price of synthetic fertilizers has increased over time during the years, making them unaffordable for most Indonesian farmers. While terrace technique to control erosion very costly.Over the last century, efforts to reduce reliance on synthetic agro-chemicals fertilizers and erosion control have recently focused on Tithonia diversifolia as a fertilizer alternative, and as hedgerow plant to control erosion. Generally known by its common name of tree marigold or Mexican sunflower, this plant has attracted considerable attention for its prolific production of green biomass, rich in nitrogen, phosphorous and potassium (NPK). In pot experiments has founded some microbial such as Mycorrhizal, Azotobacter, Azospirillum, phosphate solubilizing bacterial (PSB) and fungi (PSF) are expected to play an important role in biomass production and high nutrient uptake of this plant. This issue of importance was pursued further in the following investigation in field condition. The aim of this study was to determine the type of microbial combination suitable for Tithonia cultivation as hedgerow plants in Ultisols which have higher biomass production and nutrient content, and decline soil erosion. The field experiment was conducted with 6 treatments in a randomized block design (RBD) using 3 replications. The treatments were: Tithonia rhizosphere without microbial inoculated (A); Inokulanted by Mycorrhizal + Azotobacter + Azospirillium (B); Mycorrhizal + PSF (C); Mycorrhizal + PSB(D); Mycorrhizal + PSB + PSF(E);and without hedgerow Tithonia (F).The microbial substrates were inoculated into the Tithonia rhizosphere in the nursery. The young Tithonia plants were then planted as hedgerow on Ultisols in the experimental field for 8 months, and pruned once every 2 months. Soil erosion were collected every rainy time. The differences between treatments were statistically significant by HSD test at the 95% level of probability. The result showed that treatment C (mycorrhizal + PSB) was the most effective, and followed by treatment D (mycorrhizal + PSF) in producing higher Tithonia biomass about 8 t dry matter 2000 m-2 ha-1 y-1 and declined soil erosion 71-75%.

Keywords: hedgerow tithonia, microbial inoculants, organic fertilizer, soil erosion control

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Authors: Z. Abdessemed, N. Messaâdia, M. Houhamdi

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The PAH (Polycyclic Aromatic Hydrocarbons) represent a persistent source of pollution for oil field soils. Their degradation, essentially dominated by the aerobic bacterial and fungal flora, exhibits certain aspects for remediation of these soils microbial oxygenases have, as their substrates, a large range of PAH. The variety and the performance of these enzymes allow the initiation of the biodegradation of any PAH through many different metabolic pathways. These pathways are very important for the recycling of the PAH in the biosphere, where substances supposed indigestible by living organisms are rapidly transformed into simples compounds, directly assimilated by the intermediate metabolism of other microorganisms.

Keywords: polycyclic aromatic hydrocarbons, microbial oxygenases, biodegradation, metabolic pathways

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Authors: Frederick Otite Ighovojah

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Corrosion in the oil and gas industries is one of the most common causes of failure. Such failure includes leaks in above-ground storage tanks (AGST). The involvement of microorganisms in the corrosion process in AGST systems is often ignored, and this outlines the need to investigate the effect of microbial corrosion in oil and gas facilities. This study's methodology comprised gathering generated water samples from a nearby AGST oil facility that was operating, which were then equally divided into two batch reactors, 1 and 2. Each batch reactor was filled with five prepared X60 coupons using sterilized forceps. To provide nutrients for the microorganisms in batch reactor 1 during the test period, 2g of NPK 15- 15-15 fertilizer was added on a weekly basis. To kill the microorganisms and significantly lower their concentration in the generated water, 5ml of dissolved ozone (a biocide) with a 0.5ppm concentration was added to batch reactor 2. The weight loss measurement (WLM) was used to evaluate for corrosion. Coupons were removed from each batch reactor, and weight loss was measured at every interval of 336 hrs for 2016 hrs. The overall results obtained indicated that coupons from the batch 1 reactor showed a higher corrosion rate and higher mass loss, and this was due to the metabolic production of an aggressive compound in the medium.

Keywords: AGST, microbial corrosion, reactor, X60 steel

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Authors: Apotiola Z. O., Anyakorah C. I., Kuforiji O. O.

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Sensory and microbial properties of fresh and canned Calocybe indica (milky mushroom) were evaluated. The mushroom was grown under a controlled environment with hardwood (Cola nitida) and rice bran substrate (4:1) canned in a brine solution of salt and citric acid. Analysis was carried out using standard methods. The overall acceptability ranged between 5.62 and 6.50, with sample S30 adjudged the best. In all, significant differences p<0.01 exist in the panelist judgment. Thus, the incorporation of salt and citric acid at 3.5g and 1.5g, respectively, improved sensory attributes such as texture, aroma, color, and overall acceptability. There was no coliform and fungi growth on the samples throughout the storage period. The bacterial count, on the other hand, was observed only in the fifth and sixth week of the storage period which varied between 0.2 to 0.9 x 103 cfu/g. The highest value was observed in sample S20 of the sixth week of storage, while the lowest value was recorded in sample S30 of the sixth week of storage. Based on 16S rRNA gene sequencing, bacterial species were taxonomically confirmed as Bacillus thuringiensis. The percentile compositions and Sequence ID of the bacterial species in the mushroom was 90%.

Keywords: bacterial count, microbial property, sensory, sawdust, texture

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Authors: Georgios Psakis, Imren Rahbay, David Spiteri, Jeanice Mallia, Martin Polidano, Vasilis P. Valdramidis

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Absence of surface water and progressive groundwater quality deterioration have exacerbated scarcity rapidly, making the Mediterranean island of Malta one of the most water-stressed countries in Europe. Water scarcity challenges have been addressed by reverse osmosis desalination of seawater, 60% of which is blended with groundwater to form the current potable tap-water supply. Chlorination has been the adopted method of water disinfection prior to distribution. However, with the Malteseconsumer chlorine sensory-threshold being as low as 0.34 ppm, presence of chorine residuals and chlorination by-products in the distributed tap-water impacts negatively on its organoleptic attributes, deterring the public from consuming it. As part of the PURILMA initiative, and with the aim of minimizing the impact of chlorine residual on the quality of the distributed water, UV-C, and hydrosonication, have been identified as cost- and energy-effective decontamination alternatives, paving the way for more sustainable water management. Bench-scale assessment of the decontamination efficiency of UV-C (254 nm), revealed 4.7-Log10 inactivation for both Escherichia coli and Enterococcus faecalis at 36 mJ/cm2. At >200 mJ/cm2fluence rates, there was a systematic 2-Log10 difference in the reductions exhibited by E. coli and E. faecalis to suggest that UV-C disinfection was more effective against E. coli. Hybrid treatment schemes involving hydrosonication(at 9.5 and 12.5 dm3/min flow rates with 1-5 MPa maximum pressure) and UV-C showed at least 1.1-fold greater bactericidal activity relative to the individualized UV-C treatments. The observed inactivation appeared to have stemmed from additive effects of the combined treatments, with hydrosonication-generated reactive oxygen species enhancing the biocidal activity of UV-C.

Keywords: disinfection, groundwater, hydrosonication, UV-C

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Authors: Hamed A. El-Serehy, Khaled A. Al-Rasheid, Fahad A Al-Misned

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The meiofaunal population fluctuation, microbial dynamic and the composition of the sedimentary organic matter were investigated seasonally in the Egyptian shores along the northern part of Red Sea. Total meiofaunal population densities were extremely low with an annual average of 109 ±26 ind./10 cm2 and largely dominated by nematodes (on annual average from 52% to 94% of total meiofaunal density). The benthic microbial population densities ranged from 0.26±0.02 x 108 to 102.67±18.62 x 108/g dry sediment. Total sedimentary organic matter concentrations varied between 5.8 and 11.6 mg/g and the organic carbon, which was measured as summation of the carbohydrates, proteins and lipids, accounted for only a small fraction of being 32 % of the total organic matter. Chlorophyll a attained very low values and fluctuated between 2 and 11 µg/g. The very low chlorophyll a concentration in the Egyptian coasts along the Red Sea can suggest that the sedimentary organic matter along the Egyptian coasts is dominated by organic detrital and heterotrophic bacteria on one hand, and do not promote carbon transfer towards the higher trophic level on the other hand. However, the present study indicates that the existing of well diversified meiofaunal group, with a total of ten meiofaunal taxa, can serve as food for higher trophic levels in the Red Sea marine ecosystem.

Keywords: bacteria, meiofauna, intertidal sediments, Red Sea

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Authors: Asma Lamin, Anna H. Kaksonen, Ivan Cole, Paul White, Xiao-Bo Chen

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Microbiologically influenced corrosion (MIC) is a process in which microorganisms initiate, facilitate, or accelerate the electrochemical corrosion reactions of metallic components. Several reports documented that MIC accounts for about 20 to 40 % of the total cost of corrosion. Biofilm formation due to the presence of microorganisms on the surface of metal components is known to play a vital role in MIC, which can lead to severe consequences in various environmental and industrial settings. Quorum sensing (QS) system plays a major role in regulating biofilm formation and control the expression of some microbial enzymes. QS is a communication mechanism between microorganisms that involves the regulation of gene expression as a response to the microbial cell density within an environment. This process is employed by both Gram-positive and Gram-negative bacteria to regulate different physiological functions. QS involves production, detection, and responses to signalling chemicals, known as auto-inducers. QS controls specific processes important for the microbial community, such as biofilm formation, virulence factor expression, production of secondary metabolites and stress adaptation mechanisms. The use of QS inhibitors (QSIs) has been proposed as a possible solution to biofilm related challenges in many different applications. Although QSIs have demonstrated some strength in tackling biofouling, QSI-based strategies to control microbially influenced corrosion have not been thoroughly investigated. As such, our research aims to target the QS mechanisms as a strategy for mitigating MIC on metal surfaces in engineered systems.

Keywords: quorum sensing, quorum quenching, biofilm, biocorrosion

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Authors: Serdal Sabanci, Mutlu Çevik, Derya Tezcan, Cansu Çelebi, Filiz Içier

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Ultrasound is defined as sound waves having frequencies higher than 20 kHz, which is greater than the limits of the human hearing range. In recent years, ultrasonic treatment is an emerging technology being used increasingly in the food industry. It is applied as an alternative technique for different purposes such as microbial and enzyme inactivation, extraction, drying, filtration, crystallization, degas, cutting etc. Red beetroot (Beta vulgaris L.) is a root vegetable which is rich in mineral components, folic acid, dietary fiber, anthocyanin pigments. In this study, the application of low frequency high intensity ultrasound to the red beetroot slices and red beetroot juice for different treatment times (0, 5, 10, 15, 20 min) was investigated. Ultrasonicated red beetroot slices were also squeezed immediately. Changes on colour, betanin, pH and titratable acidity properties of red beetroot juices (the ultrasonicated juice (UJ) and the juice from ultrasonicated slices (JUS)) were determined. Although there was no significant difference statistically in the changes of color value of JUS samples due to ultrasound application (p>0.05), the color properties of UJ samples ultrasonicated for low durations were statistically different from raw material (p<0.05). The difference between color values of UJ and raw material disappeared (p>0.05) as the ultrasonication duration increased. The application of ultrasound to red beet root slices adversely affected and decreased the betanin content of JUS samples. On the other hand, the betanin content of UJ samples increased as the ultrasonication duration increased. Ultrasound treatment did not affect pH and titratable acidity of red beetroot juices statistically (p>0.05). The results suggest that ultrasound technology is the simple and economical technique which may successfully be employed for the processing of red beetroot juice with improved color and betanin quality. However, further investigation is still needed to confirm this.

Keywords: red beetroot, ultrasound, color, betanin

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Authors: Muhammad Rafiullah Khan, Vanee Chonhenchob

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The effect of sodium alginate (1%) based edible coating incorporated natural essential oils; thymol, carvone and carvacrol as antimicrobial agents at different concentrations (0.1, 0.5 and 1.0 %) on the quality changes of fresh-cut pineapple were investigated. Pineapple dipped in distilled water was served as control. After coating, fruit were sealed in a modified atmosphere package (MAP) using high permeable film; and stored at 5 °C. Gas composition in package headspace, color values (L*, a*, b*, C*), TSS, pH, ethanol, browning, and microbial decay were monitored during storage. Oxygen concentration continuously decreased while carbon dioxide concentration inside all packages continuously increased over time. Color parameters (L*, b*, c*) decreased and a* values increased during storage. All essential oils significantly (p ≤ 0.05) prevented microbial growth than control. A significantly higher (p ≤ 0.05) ethanol content was found in the control than in all other treatments. Visible microbial growth, high ethanol, and low color values limited the shelf life to 6 days in control as compared to 9 days in all other treatments. Among all essential oils, thymol at all concentrations maintained the overall quality of the pineapple and could potentially be used commercially in fresh fruit industries for longer storage.

Keywords: essential oils, antibrowning agents, antimicrobial agents, modified atmosphere packaging, pineapple, microbial decay

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Authors: Muhammad Rafiullah Khan, Vanee Chonhenchob

Abstract:

The effect of sodium alginate (1%) based edible coating incorporated natural essential oils, thymol, carvone, and carvacrol as antimicrobial agents at different concentrations (0.1, 0.5, and 1.0%) on the quality changes of fresh-cut pineapple was investigated. Pineapple dipped in distilled water was served as control. After coating, the fruit was sealed in a modified atmosphere package (MAP) using high permeable film and stored at 5°C. Gas composition in package headspace, color values (L*, a*, b*, C*), TSS, pH, ethanol, browning, and microbial decay were monitored during storage. Oxygen concentration continuously decreased while carbon dioxide concentration inside all packages continuously increased over time. Color parameters (L*, b*, c*) decreased, and a* values increased during storage. All essential oils significantly (p ≤ 0.05) prevented microbial growth than control. A significantly higher (p ≤ 0.05) ethanol content was found in the control than in all other treatments. Visible microbial growth, high ethanol, and low color values limited the shelf life to 6 days in control as compared to 9 days in all other treatments. Among all essential oils, thymol at all concentrations maintained the overall quality of the pineapple and could potentially be used commercially in fresh fruit industries for longer storage.

Keywords: essential oils, antibrowning agents, antimicrobial agents, modified atmosphere packaging, microbial decay, pineapple

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Authors: A. Jéglot, F. Plauborg, M. K. Schnorr, R. S. Sørensen, L. Elsgaard

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Artificial wetlands such as woodchip bioreactors are efficient tools to remove nitrate from agricultural wastewater with a minimized environmental impact. However, the temperature dependence of the microbiological nitrate removal prevents the woodchip bioreactors from being an efficient system when the water temperature drops below 8℃. To quantify and describe the temperature effects on nitrate removal efficiency, we studied nitrate-reducing enrichments from a woodchip bioreactor in Denmark based on samples collected in Spring and Fall. Growth was quantified as optical density, and nitrate and nitrous oxide concentrations were measured in time-course experiments to compare the growth of the microbial population and the nitrate conversion efficiencies at different temperatures. Ammonia was measured to indicate the importance of dissimilatory nitrate reduction to ammonia (DNRA) in nitrate conversion for the given denitrifying community. The temperature responses observed followed the increasing trend proposed by the Arrhenius equation, indicating higher nitrate removal efficiencies at higher temperatures. However, the growth and the nitrous oxide production observed at low temperature provided evidence of the psychrotolerance of the microbial community under study. The assays conducted showed higher nitrate removal from the microbial community extracted from the woodchip bioreactor at the cold season compared to the ones extracted during the warmer season. This indicated the ability of the bacterial populations in the bioreactor to evolve and adapt to different seasonal temperatures.

Keywords: agricultural waste water treatment, artificial wetland, denitrification, psychrophilic conditions

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Authors: Jhovana Silvia Escobar Ortega, Ines Eugenia Garcia De Salamone

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Cover crops are an agri-technological alternative to improve all properties of soils. Cover crops such as oats and rye could be used to reduce erosion and favor system sustainability when they are grown in the same agricultural cycle of the soybean crop. This crop is very profitable but its low contribution of easily decomposable residues, due to its low C/N ratio, leaves the soil exposed to erosive action and raises the need to reduce its monoculture. Furthermore, inoculation with the plant growth promoting rhizobacteria contributes to the implementation, development and production of several cereal crops. However, there is little information on its effects on forage crops which are often used as cover crops to improve soil quality. In order to evaluate the effect of combined inoculation with Azospirillum brasilense and Pseudomonas fluorescens on rhizosphere microbial communities, field experiments were conducted in the west of Buenos Aires province, Argentina, with a split-split plot randomized complete block factorial design with three replicates. The factors were: type of cover crop, inoculation and fertilization. In the main plot two levels of fertilization 0 and 7 40-0-5 (NPKS) were established at sowing. Rye (Secale cereale cultivar Quehué) and oats (Avena sativa var Aurora.) were sown in the subplots. In the sub-subplots two inoculation treatments are applied without and with application of a combined inoculant with A. brasilense and P. fluorescens. Due to the growth of cover crops has to be stopped usually with the herbicide glyphosate, rhizosphere soil of 0-20 and 20-40 cm layers was sampled at three sampling times which were: before glyphosate application (BG), a month after glyphosate application (AG) and at soybean harvest (SH). Community level of physiological profiles (CLPP) and Shannon index of microbial diversity (H) were obtained by multivariate analysis of Principal Components. Also, the most probable number (MPN) of nitrifiers and cellulolytics were determined using selective liquid media for each functional group. The CLPP of rhizosphere microbial communities showed significant differences between sampling times. There was not interaction between sampling times and both, types of cover crops and inoculation. Rhizosphere microbial communities of samples obtained BG had different CLPP with respect to the samples obtained in the sampling times AG and SH. Fertilizer and depth of sampling also caused changes in the CLPP. The H diversity index of rhizosphere microbial communities of rye in the sampling time BG were higher than those associated with oats. The MPN of both microbial functional types was lower in the deeper layer since these microorganisms are mostly aerobic. The MPN of nitrifiers decreased in rhizosphere of both cover crops only AG. At the sampling time BG, the NMP of both microbial types were larger than those obtained for AG and SH. This may mean that the glyphosate application could cause fairly permanent changes in these microbial communities which can be considered bio-indicators of soil quality. Inoculation and fertilizer inputs could be included to improve management of these cover crops because they can have a significant positive effect on the sustainability of the agro-ecosystem.

Keywords: community level of physiological profiles, microbial diversity, plant growth promoting rhizobacteria, rhizosphere microbial communities, soil quality, system sustainability

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Authors: C. T. Eze, I. N. E. Onwurah

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An important hydrogeologic problem in areas of high faults formations is high environmental health hazard occasioned by microbial and heavy metals contamination of ground waters. Consequently, we examined the microbial load and heavy metals concentration of hospital wastewater discharged into the environment at Park Lane General Hospital Enugu Urban, Nigeria. The microbial counts, characteristics and frequency of occurrences of the isolated microorganisms were determined by cultural, morphological and biochemical characteristics using established procedure while the varying concentrations of the identified heavy metals were determined using the spectrophotometric method. The microbiological analyses showed a mean total aerobic bacteria counts from 13.7 ± 0.65 × 107 to 22.8 ± 1.14 ×1010 CFU/ml, mean total anaerobic bacteria counts from 6.0 ± 1.6 × 103 to 1.7 ± 0.41 ×104 CFU/ml and mean total fungal counts from 0 ± 0 to 2.3 ± 0.16 × 105 CFU/ml. The isolated micro-organisms which included both pathogenic and non-pathogenic organisms were Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Bacillus subtilis, Proteus vulgaris, Klesbsiella pneumonia and bacteriodes sp. The only fungal isolate was Candida albican. The heavy metals identified in the leachate were Arsenic, Cadmium, Lead, Mercury and Chromium and their concentrations ranged from 0.003 ± 0.00082 to 0.14 ± 0.0082 mg/l. These values were above WHO permissible limits while others fall within the limits. Therefore, hospital waste water can pose the environmental health risk when not properly treated before discharge, especially in geologic formations with high fault formations.

Keywords: bacterial isolates, fungal isolates, heavy metals, hospital wastewater, microbial counts

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Authors: A. V. Chandewar, Sanjay Bais

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Backgound: In India, drugs of herbal origin have been used in traditional systems of medicines such as Unani and Ayurveda since ancient times. WHO limit for Escherichia coli is 101/gm cfu, for Staphylococus aureus 105/gm cfu, and for Pseudomonas aeruginosa 103/gm cfu and for Salmonella species nil cfu. WHO mentions maximum permissible limits in raw materials only for arsenic, cadmium, and lead, which amount to 1.0, 0.3, and 10 ppm, respectively. Aim: The main purpose of the investigation was to document evidence for the users, and practitioners of marketed haematinic herbal formulations. In the present study haematinic herbal formulations marketed in Yavatmal India were determined for the presence of microbial and heavy metal content. Method: The investigations were performed by using specific medias and atomic absorption spectrometry. Result: The present work indicates the presence of heavy metal contents in herbal formulations selected for study. It was found that arsenic content in formulations was below the permissible limit in all formulations. The cadmium and lead content in six formulations were above the permissible limits. Such formulations are injurious to health of patient if consumed regularly. The specific medias were used to determining the presence of Escherichia coli 4 samples, Staphylococcus aureus 3 samples, and P. aeruginosa 4 samples. The data indicated suggest that there is requirement of in process improvement to provide better quality for consumer health in order to be competitive in international markets. Summary/Conclusion: The presence of microbial and heavy metal content above WHO limits indicates that the GMP was not followed during manufacturing of herbal formulations marketed in India.

Keywords: toxicological standardization, heavy metals, microbial contamination, haematinic herbal formulations

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Authors: Kinza Khan, Dad Muhmmad, Asif Saleem, Nadia Mukhtar, Tahir Yaqub

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Ethomedicines are more commonly used in underdeveloped and developing countries. These medicines are sometimes more potent in controlling microbial infections than conventional medicines. Medicinal plants have been common practice to cure many diseases for centuries. Murraya koenigii is one of these plants and is commonly used in South Asian countries as a flavoring agent in food. To evaluate its anti-microbial activity, six different bacterial strains (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi, Bacillus cereus and Klebsiella pneumonia were used. N-hexane extract of Murraya koenigii leaves shows maximum activity against Bacillus cereus. Acetone extract of Murraya koenigii shoots showed more efficient activity against Pseudomonas aeruginosa Dichloromethane extracts showed maximum activity against Bacillus cereus. Ethanol extract exhibited maximum activity against Pseudomonas aeruginosa and Klebsiella pneumoniae. The methanol extract of Murraya koenigii shoots displayed maximum antibacterial activity against Bacillus cereus. Antifungal activity Ethanol extract was more effective against Candida albicans.

Keywords: ethnomedicines, bacteria, fungi, murraya koenigii, antimicrobial activity

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Authors: Ahreum Choi, Otgontuya Tsogbadrakh, Kwang-Hwan Jung

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Microbial rhodopsins are well-known seven-transmembrane proteins that have been extensively studied. These retinal-binding proteins have divided into two types. The type I is microbial rhodopsin, and type II (visual pigment) is expressed mostly in mammalian eyes. For type I rhodopsin, there are two main functions that are ion pumping activity and sensory transduction. Anabaena sensory rhodopsin (ASR) is one of the microbial rhodopsin with main function as photo-sensory transduction. Although ASR is expressed fairly well in Escherichia coli, the expression level is relatively less compare to Proteorhodopsin. In this study, full length of ASR was used to test for the expression influence by codon usage in E. coli. Eight amino acids of codon at N-terminal part of ASR were changed randomly with designed primers, which allow 8,192 nucleotide different cases. The codon changes were screened for the preferable codons of each residue, which have given higher expression yield. Among those 57 selected mutations, there are 24 color-enhanced E. coli colonies that contain ASR proteins, and it showed better expression level than the wild type ASR codon usage. This strongly suggests that high codon usage of only partial N-terminal of protein can increase the expression level of whole protein.

Keywords: 7-transmembrane, all-trans retinal, rhodopsin, codon-usage, protein expression

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Authors: Abhipsa Mohanty, Harit Jha

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The world's energy demands are continuing to rise, resulting in a worldwide energy crisis and environmental pollution. Because of finite, declining supply and environmental damage, reliance on fossil fuels is unsustainable. As a result, experts are concentrating on alternative, renewable, and carbon-free energy sources. Energy sources that are both environmentally and economically sustainable are required. Microbial fuel cells (MFCs) have recently received a lot of attention due to their low operating temperatures and ability to use a variety of biodegradable substrates as fuel. There are single-chamber MFCs as well as traditional MFCs with anode and cathode compartments. Bioelectricity is produced when microorganisms actively catabolize substrate. MFCs can be used as a power source in small devices like biosensors. Understanding of its components, microbiological processes, limiting variables, and construction designs in MFC systems must be simplified, and large-scale systems must be developed for them to be cost-effective as well as increase electricity production. The purpose of this research was to review current microbiology knowledge in the field of electricity. The manufacturing process, the materials, and procedures utilized to construct the technology, as well as the applications of MFC technology, are all covered.

Keywords: bio-electricity, exoelectrogenic bacteria, microbial fuel cells, soil microorganisms

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Authors: Muhammad Rafi Ullah Khan, Yaodong Guo, Vanee Chonhenchob, Jinjin Pei, Chongxing Huang

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The effect of sodium alginate (1%) based edible coating incorporated natural essential oils; thymol, carvone and carvacrol as antimicrobial agents at different concentrations (0.1, 0.5 and 1.0 %) on the quality changes of fresh-cut pineapple were investigated. Pineapple dipped in distilled water was served as control. After coating, fruit were sealed in a modified atmosphere package (MAP) using high permeable film; and stored at 5 °C. Gas composition in package headspace, color values (L*, a*, b*, C*), TSS, pH, ethanol, browning, and microbial decay were monitored during storage. Oxygen concentration continuously decreased while carbon dioxide concentration inside all packages continuously increased over time. Color parameters (L*, b*, c*) decreased and a* values increased during storage. All essential oils significantly (p ≤ 0.05) prevented microbial growth than control. A significantly higher (p ≤ 0.05) ethanol content was found in the control than in all other treatments. Visible microbial growth, high ethanol, and low color values limited the shelf life to 6 days in control as compared to 9 days in all other treatments. Among all essential oils, thymol at all concentrations maintained the overall quality of the pineapple and could potentially be used commercially in fresh fruit industries for longer storage.

Keywords: essential oils, antibrowning agents, antimicrobial agents, modified atmosphere packaging, microbial decay, pineapple

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Authors: Md. Maksudur Rahman Khan, Chee Wai Woon, Huei Ruey Ong, Vignes Rasiah, Chin Kui Cheng, Kar Min Chan, E. Baranitharan

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The present work represents a preparation of non-precious iron-based electrocatalyst (FeN) for ORR in air-cathode microbial fuel cell by pyrolysis treatment. Iron oxalate which recovered from the industrial wastewater and Phenanthroline (Phen) were used as the iron and nitrogen precursors, respectively in preparing FeN catalyst. The performance of as prepared catalyst (FeN) was investigated in a single chambered air cathode MFC in which anaerobic sludge was used as inoculum and palm oil mill effluent as substrate. The maximum open circuit potential (OCV) and the highest power density recorded were 0.543 V and 4.9 mW/m2, respectively. Physical characterization of FeN was elucidated by using Brunauner Emmett Teller (BET), X-Ray Diffraction (XRD) analysis and Field Emission Scanning Electron Microscopy (FESEM) while the electrochemical properties were characterized by cyclic voltammetry (CV) analysis. The presence of biofilm on anode surface was examined using FESEM and confirmed using Infrared Spectroscopy and Thermogravimetric Analysis. The findings of this study demonstrated that FeN is electrochemically active and further modification is needed to increase the ORR catalytic activity.

Keywords: iron based catalyst, microbial fuel cells, oxygen reduction reaction, palm oil mill effluent

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Authors: Pouya Karimi, Ramin Gasemi Shayan, Parsa Sheykhzade

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Ease shotgun DNA sequencing is changing the microbial sciences. Sequencing instruments are compelling to the point that example planning is currently the key constraining element. Here, we present a microfluidic test readiness stage that incorporates the key strides in cells to grouping library test groundwork for up to 96 examples and decreases DNA input prerequisites 100-overlay while keeping up or improving information quality. The universally useful microarchitecture we show bolsters work processes with subjective quantities of response and tidy up or catch steps. By decreasing the example amount necessities, we empowered low-input (∼10,000 cells) entire genome shotgun (WGS) sequencing of Mycobacterium tuberculosis and soil miniaturized scale settlements with prevalent outcomes. We additionally utilized the upgraded throughput to succession ∼400 clinical Pseudomonas aeruginosa libraries and exhibit magnificent single-nucleotide polymorphism discovery execution that clarified phenotypically watched anti-toxin opposition. Completely coordinated lab-on-chip test arrangement beats specialized boundaries to empower more extensive organization of genomics across numerous fundamental research and translational applications.

Keywords: clinical microbiology, DNA, microbiology, microbial genomics

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Authors: Jakub Elbl, Lukáš Plošek, Antonín Kintl, Jaroslav Hynšt, Soňa Javoreková, Jaroslav Záhora, Libor Kalhotka, Olga Urbánková, Ivana Charousová

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This work presents the first results from the long-term laboratory experiment dealing with impact of drought on soil properties. Three groups of the treatment (A, B and C) with different regime of irrigation were prepared. The soil water content was maintained at 70 % of soil water holding capacity in group A, at 40 % in group B. In group C, soil water regime was maintained in the range of wilting point. Each group of the experiment was divided into three variants (A1 = B1, C1; A2 = B2, C2 etc.) with three repetitions: Variants A1 (B1, C1) were controls without addition of another fertilizer. Variants A2 (B2, C2) were fertilized with mineral nitrogen fertilizer DAM 390 (0.140 Mg of N per ha) and variants A3 (B3, C3) contained 45 g of Cp per a pot. The significant differences (ANOVA, P<0.05) in the leaching of mineral nitrogen and values of saturated hydraulic conductivity (Ksat) were found. The highest values of Ksat were found in variants (within each group) with addition of compost (A3, B3, C3). Conversely, the lowest values of Ksat were found in variants with addition of mineral nitrogen. Low values of Ksat indicate an increased level of hydrophobicity in individual groups of the experiment. Moreover, all variants with compost addition showed lower amount of mineral nitrogen leaching and high level of microbial activity than variants without. This decrease of mineral nitrogen leaching was about 200 % in comparison with the control variant and about 300 % with variant, where mineral nitrogen was added. Based on these results, we can conclude that changes of soil water content directly have impact on microbial activity, soil hydrophobicity and loss of mineral nitrogen from the soil.

Keywords: drought, microbial activity, mineral nitrogen, soil hydrophobicity

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Authors: Muhammad Adeel Arshad, Faiz-Ul Hassan, Yanfen Cheng

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According to FAO, enteric methane (CH4) production is about 44% of all greenhouse gas emissions from the livestock sector. Ruminants produce CH4 as a result of fermentation of feed in the rumen especially from roughages which yield more CH4 per unit of biomass ingested as compared to concentrates. Efficient ruminal fermentation is not possible without abating CO2 and CH4. Methane abatement strategies are required to curb the predicted rise in emissions associated with greater ruminant production in future to meet ever increasing animal protein requirements. Ecology of ruminal methanogenesis and avenues for its mitigation can be identified through various genomic and transcriptomic techniques. Programs such as Hungate1000 and the Global Rumen Census have been launched to enhance our understanding about global ruminal microbial communities. Through Hungate1000 project, a comprehensive reference set of rumen microbial genome sequences has been developed from cultivated rumen bacteria and methanogenic archaea along with representative rumen anaerobic fungi and ciliate protozoa cultures. But still many species of rumen microbes are underrepresented especially uncultivable microbes. Lack of sequence information specific to the rumen's microbial community has inhibited efforts to use genomic data to identify specific set of species and their target genes involved in methanogenesis. Metagenomic and metatranscriptomic study of entire microbial rumen populations offer new perspectives to understand interaction of methanogens with other rumen microbes and their potential association with total gas and methane production. Deep understanding of methanogenic pathway will help to devise potentially effective strategies to abate methane production while increasing feed efficiency in ruminants.

Keywords: Genome sequences, Hungate1000, methanogens, ruminal fermentation

Procedia PDF Downloads 106

Authors: Uchegbu Nneka Nkechi, Okoye Ogochukwu Peace

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The evaluation of the visco-elastic properties and microbial quality of a formulated oat-based dietetic food were investigated. Oat flour, pumpkin seed flour, carrot flour and skimmed milk powder were blended in varying proportions to formulate a product with codes OCF, which contains 70% oat flour, 10 % carrot flour, 10 % pumpkin seed flour and 10% skimmed milk powder, OCF which contains 65 % oat flour, 10 % carrot flour, 10 % pumpkin seed flour and 15 % skimmed milk powder, OCF which contains 60 % oat flour, 10 % carrot flour, 10 % pumpkin seed flour and 20 % skimmed milk powder, OCF which contains 55 % oat flour, 10 % carrot flour, 10 % pumpkin seed flour and 25 % skimmed milk powder and OF with 95 % oat as the commercial control. All the samples were assessed for their proximate composition, microbial quality and visco-elastic properties. The moisture content was highest at sample OF (10.73%) and lowest at OCF (7.10%) (P<0.05). Crude protein ranged from 13.38%-22.86%, with OCF having the highest (P<0.05) protein content and OF having the lowest. Crude fat was 3.74% for OCF and 6.31% for OF. Crude fiber ranged from 3.58% - 17.39% with OF having the lowest (P<0.05) fiber content and OCF having the highest. Ash content was 1.30% for OCF and 2.75% for OCF. There was no mold growth in the samples. The total viable ml/wl count ranged from 1.5×10³ cfu/g - 2.6×10³ cfu/g, with OCF having the lowest and OF having the highest (P<0.05) total viable count. The peak viscosity of the sample ranged from 75.00 cP-2895.00 cP, with OCF having the lowest and OF having the highest value. The final viscosity was 130.50 cP in OCF and 3572.50 cP in OF. The setback viscosity was 58.00 cP in OCF and 1680.50 cP in OF. The peak time was 6.93 mins in OCF to 5.57 mins in OF. There was no pasting temperature for all samples except the OF, which had 86.43. Sample OF was the highest in terms of overall acceptability. This study showed that the oat-based composite flour produced had a nutritional profile that would be acceptable for the aged population.

Keywords: dietetic, pumpkin, visco-elastic, microbial

Procedia PDF Downloads 167