Search results for: microbial enzymes
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1518

Search results for: microbial enzymes

1518 Analysis of a Lignocellulose Degrading Microbial Consortium to Enhance the Anaerobic Digestion of Rice Straws

Authors: Supanun Kangrang, Kraipat Cheenkachorn, Kittiphong Rattanaporn, Malinee Sriariyanun

Abstract:

Rice straw is lignocellulosic biomass which can be utilized as substrate for the biogas production. However, due to the property and composition of rice straw, it is difficult to be degraded by hydrolysis enzymes. One of the pretreatment method that modifies such properties of lignocellulosic biomass is the application of lignocellulose-degrading microbial consortia. The aim of this study is to investigate the effect of microbial consortia to enhance biogas production. To select the high efficient consortium, cellulase enzymes were extracted and their activities were analyzed. The results suggested that microbial consortium culture obtained from cattle manure is the best candidate compared to decomposed wood and horse manure. A microbial consortium isolated from cattle manure was then mixed with anaerobic sludge and used as inoculum for biogas production. The optimal conditions for biogas production were investigated using response surface methodology (RSM). The tested parameters were the ratio of amount of microbial consortium isolated and amount of anaerobic sludge (MI:AS), substrate to inoculum ratio (S:I) and temperature. Here, the value of the regression coefficient R2 = 0.7661 could be explained by the model which is high to advocate the significance of the model. The highest cumulative biogas yield was 104.6 ml/g-rice straw at optimum ratio of MI:AS, ratio of S:I, and temperature of 2.5:1, 15:1 and 44°C respectively.

Keywords: lignocellulolytic biomass, microbial consortium, cellulase, biogas, Response Surface Methodology (RSM)

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1517 A Proteomic Approach for Discovery of Microbial Cellulolytic Enzymes

Authors: M. S. Matlala, I. Ignatious

Abstract:

Environmental sustainability has taken the center stage in human life all over the world. Energy is the most essential component of our life. The conventional sources of energy are non-renewable and have a detrimental environmental impact. Therefore, there is a need to move from conventional to non-conventional renewable energy sources to satisfy the world’s energy demands. The study aimed at screening for microbial cellulolytic enzymes using a proteomic approach. The objectives were to screen for microbial cellulases with high specific activity and separate the cellulolytic enzymes using a combination of zymography and two-dimensional (2-D) gel electrophoresis followed by tryptic digestion, Matrix-assisted Laser Desorption Ionisation-Time of Flight (MALDI-TOF) and bioinformatics analysis. Fungal and bacterial isolates were cultured in M9 minimal and Mandel media for a period of 168 hours at 60°C and 30°C with cellobiose and Avicel as carbon sources. Microbial cells were separated from supernatants through centrifugation, and the crude enzyme from the cultures was used for the determination of cellulase activity, zymography, SDS-PAGE, and two-dimensional gel electrophoresis. Five isolates, with lytic action on carbon sources studied, were a bacterial strain (BARK) and fungal strains (VCFF1, VCFF14, VCFF17, and VCFF18). Peak cellulase production by the selected isolates was found to be 3.8U/ml, 2.09U/ml, 3.38U/ml, 3.18U/ml, and 1.95U/ml, respectively. Two-dimensional gel protein maps resulted in the separation and quantitative expression of different proteins by the microbial isolates. MALDI-TOF analysis and database search showed that the expressed proteins in this study closely relate to different glycoside hydrolases produced by other microbial species with an acceptable confidence level of 100%.

Keywords: cellulases, energy, two-dimensional gel electrophoresis, matrix-assisted laser desorption ionisation-time of flight, MALDI-TOF MS

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1516 Fructooligosaccharide Prebiotics: Optimization of Different Cultivation Parameters on Their Microbial Production

Authors: Elsayed Ahmed Elsayed, Azza Noor El-Deen, Mohamed A. Farid, Mohamed A. Wadaan

Abstract:

Recently, a great attention has been paid to the use of dietary carbohydrates as prebiotic functional foods. Among the new commercially available products, fructooligosaccharides (FOS), which are microbial produced from sucrose, have attracted special interest due to their valuable properties and, thus, have a great economic potential for the sugar industrial branch. They are non-cariogenic sweeteners of low caloric value, as they are not hydrolyzed by the gastro-intestinal enzymes, promoting selectively the growth of the bifidobacteria in the colon, helping to eliminate the harmful microbial species to human and animal health and preventing colon cancer. FOS has been also found to reduce cholesterol, phospholipids and triglyceride levels in blood. FOS has been mainly produced by microbial fructosyltransferase (FTase) enzymes. The present work outlines bioprocess optimization for different cultivation parameters affecting the production of FTase by Penicillium aurantiogriseum AUMC 5605. The optimization involves both traditional as well as fractional factorial design approaches. Additionally, the production process will be compared under batch and fed-batch conditions. Finally, the optimized process conditions will be applied to 5-L stirred tank bioreactor cultivations.

Keywords: prebiotics, fructooligosaccharides, optimization, cultivation

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1515 Reduced Tillage and Bio-stimulant Application Can Improve Soil Microbial Enzyme Activity in a Dryland Cropping System

Authors: Flackson Tshuma, James Bennett, Pieter Andreas Swanepoel, Johan Labuschagne, Stephan van der Westhuizen, Francis Rayns

Abstract:

Amongst other things, tillage and synthetic agrochemicals can be effective methods of seedbed preparation and pest control. Nonetheless, frequent and intensive tillage and excessive application of synthetic agrochemicals, such as herbicides and insecticides, can reduce soil microbial enzyme activity. A decline in soil microbial enzyme activity can negatively affect nutrient cycling and crop productivity. In this study, the effects of four tillage treatments; continuous mouldboard plough; shallow tine-tillage to a depth of about 75 mm; no-tillage; and tillage rotation (involving shallow tine-tillage once every four years in rotation with three years of no-tillage), and two rates of synthetic agrochemicals (standard: with regular application of synthetic agrochemicals; and reduced: fewer synthetic agrochemicals in combination with bio-chemicals/ or bio-stimulants) on soil microbial enzyme activity were investigated between 2018 and 2020 in a typical Mediterranean climate zone in South Africa. Four different bio-stimulants applied contained: Trichoderma asperellum, fulvic acid, silicic acid, and Nereocystis luetkeana extracts, respectively. The study was laid out as a complete randomised block design with four replicated blocks. Each block had 14 plots, and each plot measured 50 m x 6 m. The study aimed to assess the combined impact of tillage practices and reduced rates of synthetic agrochemical application on soil microbial enzyme activity in a dryland cropping system. It was hypothesised that the application of bio-stimulants in combination with minimum soil disturbance will lead to a greater increase in microbial enzyme activity than the effect of applying either in isolation. Six soil cores were randomly and aseptically collected from each plot for microbial enzyme activity analysis from the 0-150 mm layer of a field trial under a dryland crop rotation system in the Swartland region. The activities of four microbial enzymes, β-glucosidase, acid phosphatase, alkaline phosphatase and urease, were assessed. The enzymes are essential for the cycling of glucose, phosphorus, and nitrogen, respectively. Microbial enzyme activity generally increased with a reduction of both tillage intensity and synthetic agrochemical application. The use of the mouldboard plough led to the least (P<0.05) microbial enzyme activity relative to the reduced tillage treatments, whereas the system with bio-stimulants (reduced synthetic agrochemicals) led to the highest (P<0.05) microbial enzyme activity relative to the standard systems. The application of bio-stimulants in combination with reduced tillage, particularly no-tillage, could be beneficial for enzyme activity in a dryland farming system.

Keywords: bio-stimulants, soil microbial enzymes, synthetic agrochemicals, tillage

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1514 Immobilization of Enzymes and Proteins on Epoxy-Activated Supports

Authors: Ehsan Khorshidian, Afshin Farahbakhsh, Sina Aghili

Abstract:

Enzymes are promising biocatalysts for many organic reactions. They have excellent features like high activity, specificity and selectivity, and can catalyze under mild and environment friendly conditions. Epoxy-activated supports are almost-ideal ones to perform very easy immobilization of proteins and enzymes at both laboratory and industrial scale. The activated epoxy supports (chitosan/alginate, Eupergit C) may be very suitable to achieve the multipoint covalent attachment of proteins and enzymes, therefore, to stabilize their three-dimensional structure. The enzyme is firstly covalently immobilized under conditions pH 7.0 and 10.0. The remaining groups of the support are blocked to stop additional interaction between the enzyme and support by mercaptoethanol or Triton X-100. The results show support allowed obtaining biocatalysts with high immobilized protein amount and hydrolytic activity. The immobilization of lipases on epoxy support may be considered as attractive tool for obtaining highly active biocatalysts to be used in both aqueous and anhydrous aqueous media.

Keywords: immobilization of enzymes, epoxy supports, enzyme multipoint covalent attachment, microbial lipases

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1513 Second Generation Biofuels: A Futuristic Green Deal for Lignocellulosic Waste

Authors: Nivedita Sharma

Abstract:

The global demand for fossil fuels is very high, but their use is not sustainable since its reserves are declining. Additionally, fossil fuels are responsible for the accumulation of greenhouse gases. The emission of greenhouse gases from the transport sector can be reduced by substituting fossil fuels by biofuels. Thus, renewable fuels capable of sequestering carbon dioxide are in high demand. Second‐generation biofuels, which require lignocellulosic biomass as a substrate and ultimately producing ethanol, fall largely in this category. Bioethanol is a favorable and near carbon-neutral renewable biofuel leading to reduction in tailpipe pollutant emission and improving the ambient air quality. Lignocellulose consists of three main components: cellulose, hemicellulose and lignin which can be converted to ethanol with the help of microbial enzymes. Enzymatic hydrolysis of lignocellulosic biomass in 1st step is considered as the most efficient and least polluting methods for generating fermentable hexose and pentose sugars which subsequently are fermented to power alcohol by yeasts in 2nd step of the process. In the present technology, a complete bioconversion process i.e. potential hydrolytic enzymes i.e. cellulase and xylanase producing microorganisms have been isolated from different niches, screened for enzyme production, identified using phenotyping and genotyping, enzyme production, purification and application of enzymes for saccharification of different lignocellulosic biomass followed by fermentation of hydrolysate to ethanol with high yield is to be presented in detail.

Keywords: cellulase, xylanase, lignocellulose, bioethanol, microbial enzymes

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1512 Synthesis, Characterization, Validation of Resistant Microbial Strains and Anti Microbrial Activity of Substitted Pyrazoles

Authors: Rama Devi Kyatham, D. Ashok, K. S. K. Rao Patnaik, Raju Bathula

Abstract:

We have shown the importance of pyrazoles as anti-microbial chemical entities. These compounds have generally been considered significant due to their wide range of pharmacological acivities and their discovery motivates new avenues of research.The proposed pyrazoles were synthesized and evaluated for their anti-microbial activities. The Synthesized compounds were analyzed by different spectroscopic methods.

Keywords: pyrazoles, validation, resistant microbial strains, anti-microbial activities

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1511 Stability of a Biofilm Reactor Able to Degrade a Mixture of the Organochlorine Herbicides Atrazine, Simazine, Diuron and 2,4-Dichlorophenoxyacetic Acid to Changes in the Composition of the Supply Medium

Authors: I. Nava-Arenas, N. Ruiz-Ordaz, C. J. Galindez-Mayer, M. L. Luna-Guido, S. L. Ruiz-López, A. Cabrera-Orozco, D. Nava-Arenas

Abstract:

Among the most important herbicides, the organochlorine compounds are of considerable interest due to their recalcitrance to the chemical, biological, and photolytic degradation, their persistence in the environment, their mobility, and their bioacummulation. The most widely used herbicides in North America are primarily 2,4-dichlorophenoxyacetic acid (2,4-D), the triazines (atrazine and simazine), and to a lesser extent diuron. The contamination of soils and water bodies frequently occurs by mixtures of these xenobiotics. For this reason, in this work, the operational stability to changes in the composition of the medium supplied to an aerobic biofilm reactor was studied. The reactor was packed with fragments of volcanic rock that retained a complex microbial film, able to degrade a mixture of organochlorine herbicides atrazine, simazine, diuron and 2,4-D, and whose members have microbial genes encoding the main catabolic enzymes atzABCD, tfdACD and puhB. To acclimate the attached microbial community, the biofilm reactor was fed continuously with a mineral minimal medium containing the herbicides (in mg•L-1): diuron, 20.4; atrazine, 14.2, simazine, 11.4, and 2,4-D, 59.7, as carbon and nitrogen sources. Throughout the bioprocess, removal efficiencies of 92-100% for herbicides, 78-90% for COD, 92-96% for TOC and 61-83% for dehalogenation were reached. In the microbial community, the genes encoding catabolic enzymes of different herbicides tfdACD, puhB and, occasionally, the genes atzA and atzC were detected. After the acclimatization, the triazine herbicides were eliminated from the mixture formulation. Volumetric loading rates of the mixture 2,4-D and diuron were continuously supplied to the reactor (1.9-21.5 mg herbicides •L-1 •h-1). Along the bioprocess, the removal efficiencies obtained were 86-100% for the mixture of herbicides, 63-94% for for COD, 90-100% for COT, and dehalogenation values of 63-100%. It was also observed that the genes encoding the enzymes in the catabolism of both herbicides, tfdACD and puhB, were consistently detected; and, occasionally, the atzA and atzC. Subsequently, the triazine herbicide atrazine and simazine were restored to the medium supply. Different volumetric charges of this mixture were continuously fed to the reactor (2.9 to 12.6 mg herbicides •L-1 •h-1). During this new treatment process, removal efficiencies of 65-95% for the mixture of herbicides, 63-92% for COD, 66-89% for TOC and 73-94% of dehalogenation were observed. In this last case, the genes tfdACD, puhB and atzABC encoding for the enzymes involved in the catabolism of the distinct herbicides were consistently detected. The atzD gene, encoding the cyanuric hydrolase enzyme, could not be detected, though it was determined that there was partial degradation of cyanuric acid. In general, the community in the biofilm reactor showed some catabolic stability, adapting to changes in loading rates and composition of the mixture of herbicides, and preserving their ability to degrade the four herbicides tested; although, there was a significant delay in the response time to recover to degradation of the herbicides.

Keywords: biodegradation, biofilm reactor, microbial community, organochlorine herbicides

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1510 Influence of Moss Cover and Seasonality on Soil Microbial Biomass and Enzymatic Activity in Different Central Himalayan Temperate Forest Types

Authors: Anshu Siwach, Qianlai Zhuang, Ratul Baishya

Abstract:

Context: This study focuses on the influence of moss cover and seasonality on soil microbial biomass and enzymatic activity in different Central Himalayan temperate forest types. Soil microbial biomass and enzymes are key indicators of microbial communities in soil and provide information on soil properties, microbial status, and organic matter dynamics. The activity of microorganisms in the soil varies depending on the vegetation type and environmental conditions. Therefore, this study aims to assess the effects of moss cover, seasons, and different forest types on soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), and soil enzymatic activity in the Central Himalayas, Uttarakhand, India. Research Aim: The aim of this study is to evaluate the levels of SMBC, SMBN, and soil enzymatic activity in different temperate forest types under the influence of two ground covers (soil with and without moss cover) during the rainy and winter seasons. Question Addressed: This study addresses the following questions: 1. How does the presence of moss cover and seasonality affect soil microbial biomass and enzymatic activity? 2. What is the influence of different forest types on SMBC, SMBN, and enzymatic activity? Methodology: Soil samples were collected from different forest types during the rainy and winter seasons. The study utilizes the chloroform-fumigation extraction method to determine SMBC and SMBN. Standard methodologies are followed to measure enzymatic activities, including dehydrogenase, acid phosphatase, aryl sulfatase, β-glucosidase, phenol oxidase, and urease. Findings: The study reveals significant variations in SMBC, SMBN, and enzymatic activity under different ground covers, within the rainy and winter seasons, and among the forest types. Moss cover positively influences SMBC and enzymatic activity during the rainy season, while soil without moss cover shows higher values during the winter season. Quercus-dominated forests, as well as Cupressus torulosa forests, exhibit higher levels of SMBC and enzymatic activity, while Pinus roxburghii forests show lower levels. Theoretical Importance: The findings highlight the importance of considering mosses in forest management plans to improve soil microbial diversity, enzymatic activity, soil quality, and health. Additionally, this research contributes to understanding the role of lower plants, such as mosses, in influencing ecosystem dynamics. Conclusion: The study concludes that moss cover during the rainy season significantly influences soil microbial biomass and enzymatic activity. Quercus and Cupressus torulosa dominated forests demonstrate higher levels of SMBC and enzymatic activity, indicating the importance of these forest types in sustaining soil microbial diversity and soil health. Including mosses in forest management plans can improve soil quality and overall ecosystem dynamics.

Keywords: moss cover, seasons, soil enzymes, soil microbial biomass, temperate forest types

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1509 Study of Polycyclic Aromatic Hydrocarbons Biodegradation by Bacterial Isolated from Contaminated Soils

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

Abstract:

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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1508 LIFirr with an Indicator of Microbial Activity in Paraffinic Oil

Authors: M. P. Casiraghi, C. M. Quintella, P. Almeida

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Paraffinic oils were submitted to microbial action. The microorganisms consisted of bacteria of the genera Pseudomonas sp and Bacillus lincheniforms. The alterations in interfacial tension were determined using a tensometer and applying the hanging drop technique at room temperature (299 K ±275 K). The alteration in the constitution of the paraffins was evaluated by means of gas chromatography. The microbial activity was observed to reduce interfacial tension by 54 to 78%, as well as consuming the paraffins C19 to C29 and producing paraffins C36 to C44. The LIFirr technique made it possible to determine the microbial action quickly.

Keywords: paraffins, biosurfactants, LIFirr, microbial activity

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1507 Bioprospecting of Marine Actinobacteria: The Leading Way for Industrially Important Enzymes and Bioactive Natural Products

Authors: Ramesh Subramani, Mathivanan Narayanasamy, William Aalbersberg

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It is well accepted by last 35 years of research and on-going programmes that marine environment harbours abundant and unique biodiversity, which is currently playing as an important source in bioprospecting. It has become apparent that marine microorganisms are lead in the biodiscovery. Among marine organisms, actinobacteria are a target phylum for discovering novel antibiotics against increasing the multi-drug resistant human pathogens because of these taxa representing for novel genera and species. Marine actinomycetes are a proven source of new antibiotic leads and novel enzymes with important industrial applications. A total of 183 streptomycete and 25 non-streptomycete strains were isolated from different marine samples collected from north-eastern part of the Indian Ocean. Among them, 111 isolates displayed antibacterial activity against human pathogens and 151 exhibited antifungal activity against phytopathogens. Importantly, most of them produced various extracellular enzymes and 58 of them produced exopolysaccharides. Totally eight small bioactive compounds and a thermostable alkaline protease have been purified from a selected strain, Streptomyces fungicidicus. Besides, our on-going studies on non-streptomycete strains (rare actinomycetes) are most likely promising resource for new and unique compounds against current emerging drug-resistant pathogens. We have just recognised the chemical diversity in marine microorganisms. Therefore it is worthwhile to continue the exploration of marine microorganisms for new drug leads, novel enzymes and other bioprospecting research.

Keywords: bioactive compounds, industrial enzymes, marine actinobacteria, microbial metabolites, marine natural products

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1506 Isolation of Protease Producing Bacteria from Soil Sediments of Ayiramthengu Mangrove Ecosystem

Authors: Reshmi Vijayan

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Alkaline protease is one of the most important enzymes in the biological world. Microbial production of alkaline protease is getting more attention from researchers due to its unique properties and substantial activity. Microorganisms are the most common sources of commercial enzymes due to their physiological and biochemical properties. The study was conducted on Ayiramthenghu mangrove sediments to isolate protease producing bacteria. All the isolates were screened for proteolytic activity on a skim milk agar plate at 37˚C for 48hrs. Protease activities were determined by the formation of a clear zone around the colonies on Skim milk agar medium. The activity of the enzyme was measured by the tyrosine standard curve, and it was found to be 0.186285 U/ml/min.

Keywords: protease, protease assay, skim milk agar medium, mangrove ecosystem

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1505 Improvement on the Specific Activities of Immobilized Enzymes by Poly(Ethylene Oxide) Surface Modification

Authors: Shaohua Li, Aihua Zhang, Kelly Zatopek, Saba Parvez, Andrew F. Gardner, Ivan R. Corrêa Jr., Christopher J. Noren, Ming-Qun Xu

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Covalent immobilization of enzymes on solid supports is an alternative approach to biocatalysis with the added benefits of simple enzyme removal, improved stability, and adaptability to automation and high-throughput applications. Nevertheless, immobilized enzymes generally suffer from reduced activities compared to their soluble counterparts. One major factor leading to activity loss is the intrinsic hydrophobic property of the supporting material surface, which could result in the conformational change/confinement of enzymes. We report a strategy of utilizing flexible poly (ethylene oxide) (PEO) moieties as to improve the surface hydrophilicity of solid supports used for enzyme immobilization. DNA modifying enzymes were covalently conjugated to PEO-coated magnetic-beads. Kinetics studies proved that the activities of the covalently-immobilized DNA modifying enzymes were greatly enhanced by the PEO modification on the bead surface.

Keywords: immobilized enzymes, biocatalysis, poly(ethylene oxide), surface modification

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1504 Bioremediation of PAHs-Contaminated Soil Using Land Treatment Processes

Authors: Somaye Eskandary

Abstract:

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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1503 Formaldehyde Degradation from Indoor Air by Encapsulated Microbial Cells

Authors: C. C. Castro, T. Senechal, D. Lahem, A. L. Hantson

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Formaldehyde is one of the most representative volatile organic compounds present in the indoor air of residential units and workplaces. Increased attention has been given to this toxic compound because of its carcinogenic effect in health. Biological or enzymatic transformation is being explored to degrade this pollutant. Pseudomonas putida is a bacteria able to synthesize formaldehyde dehydrogenase, an enzyme known to use formaldehyde as a substrate and transform it into less toxic compounds. The immobilization of bacterial cells in the surface of different supports through spraying or dip-coating is herein proposed. The determination of the enzymatic activity on the coated surfaces was performed as well as the study of its effect on formaldehyde degradation in an isolated chamber. Results show that the incorporation of microbial cells able to synthesize depolluting enzymes can be an innovative, low-cost, effective and environmentally friendly solution for indoor air depollution.

Keywords: cells encapsulation, formaldehyde, formaldehyde dehydrogenase, indoor air depollution

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1502 Microbial Degradation of Lignin for Production of Valuable Chemicals

Authors: Fnu Asina, Ivana Brzonova, Keith Voeller, Yun Ji, Alena Kubatova, Evguenii Kozliak

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Lignin, a heterogeneous three-dimensional biopolymer, is one of the building blocks of lignocellulosic biomass. Due to its limited chemical reactivity, lignin is currently processed as a low-value by-product in pulp and paper mills. Among various industrial lignins, Kraft lignin represents a major source of by-products generated during the widely employed pulping process across the pulp and paper industry. Therefore, valorization of Kraft lignin holds great potential as this would provide a readily available source of aromatic compounds for various industrial applications. Microbial degradation is well known for using both highly specific ligninolytic enzymes secreted by microorganisms and mild operating conditions compared with conventional chemical approaches. In this study, the degradation of Indulin AT lignin was assessed by comparing the effects of Basidiomycetous fungi (Coriolus versicolour and Trametes gallica) and Actinobacteria (Mycobacterium sp. and Streptomyces sp.) to two commercial laccases, T. versicolour ( ≥ 10 U/mg) and C. versicolour ( ≥ 0.3 U/mg). After 54 days of cultivation, the extent of microbial degradation was significantly higher than that of commercial laccases, reaching a maximum of 38 wt% degradation for C. versicolour treated samples. Lignin degradation was further confirmed by thermal carbon analysis with a five-step temperature protocol. Compared with commercial laccases, a significant decrease in char formation at 850ºC was observed among all microbial-degraded lignins with a corresponding carbon percentage increase from 200ºC to 500ºC. To complement the carbon analysis result, chemical characterization of the degraded products at different stages of the delignification by microorganisms and commercial laccases was performed by Pyrolysis-GC-MS.

Keywords: lignin, microbial degradation, pyrolysis-GC-MS, thermal carbon analysis

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1501 Enhanced Enzymes Production through Immobilization of Filamentous Fungi

Authors: Zhanara B. Suleimenova, Zhazira K. Saduyeva

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Filamentous fungi are major producers of enzymes that have important applications in the food and beverage industries. The overall objective of this research is a strain improvement technology for efficient industrial enzymes production. The new way of filamentous fungi cultivation method has been developed. Such technology prolong producers’ cultivation period up to 60 days and create the opportunity to obtain enzymes repeatedly in every 2-3 days of fungal cultivation. This method is based on immobilizing enzymes producers with solid support in submerged conditions of growth. Immobilizing has a range of advantages: Decreasing the price of the final product, absence of foreign substances, controlled process of enzyme-genesis, ability of various enzymes simultaneous production, etc. Design of proposed technology gives the opportunity to increase the activity of immobilized cells culture filtrate comparing to free cells, growing in periodic culture conditions. Thus, proposed research focuses on new, more versatile, microorganisms capable of squeezing more end-products as well as proposed cultivation technology led to increased enzymatic productivity by several times.

Keywords: filamentous fungi, immobilization, industrial enzymes production, strain improvement

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1500 Quorum-Sensing Driven Inhibitors for Mitigating Microbial Influenced Corrosion

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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1499 Restoration and Conservation of Historical Textiles Using Covalently Immobilized Enzymes on Nanoparticles

Authors: Mohamed Elbehery

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Historical textiles in the burial environment or in museums are exposed to many types of stains and dirt that are associated with historical textiles by multiple chemical bonds that cause damage to historical textiles. The cleaning process must be carried out with great care, with no irreversible damage, and sediments removed without affecting the original material of the surface being cleaned. Science and technology continue to provide innovative systems in the bio-cleaning process (using pure enzymes) of historical textiles and artistic surfaces. Lipase and α-amylase were immobilized on nanoparticles of alginate/κ-carrageenan nanoparticle complex and used in historical textiles cleaning. Preparation of nanoparticles, activation, and enzymes immobilization were characterized. Optimization of loading time and units of the two enzymes were done. It was found that, the optimum time and units of amylase were 4 hrs and 25U, respectively. While, the optimum time and units of lipase were 3 hrs and 15U, respectively. The methods used to examine the fibers using a scanning electron microscope equipped with an X-ray energy dispersal unit: SEM with EDX unit.

Keywords: nanoparticles, enzymes, immobilization, textiles

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1498 Comparative Analysis of Enzyme Activities Concerned in Decomposition of Toluene

Authors: Ayuko Itsuki, Sachiyo Aburatani

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In recent years, pollutions of the environment by toxic substances become a serious problem. While there are many methods of environmental clean-up, the methods by microorganisms are considered to be reasonable and safety for environment. Compost is known that it catabolize the meladorous substancess in its production process, however the mechanism of its catabolizing system is not known yet. In the catabolization process, organic matters turn into inorganic by the released enzymes from lots of microorganisms which live in compost. In other words, the cooperative of activated enzymes in the compost decomposes malodorous substances. Thus, clarifying the interaction among enzymes is important for revealing the catabolizing system of meladorous substance in compost. In this study, we utilized statistical method to infer the interaction among enzymes. We developed a method which combined partial correlation with cross correlation to estimate the relevance between enzymes especially from time series data of few variables. Because of using cross correlation, we can estimate not only the associative structure but also the reaction pathway. We applied the developed method to the enzyme measured data and estimated an interaction among the enzymes in decomposition mechanism of toluene.

Keywords: enzyme activities, comparative analysis, compost, toluene

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1497 Production of Lignocellulosic Enzymes by Bacillus safensis LCX Using Agro-Food Wastes in Solid State Fermentation

Authors: Abeer A. Q. Ahmed, Tracey McKay

Abstract:

The increasing demand for renewable fuels and chemicals is pressuring manufacturing industry toward finding more sustainable cost-effective resources. Lignocellulose, such as agro-food wastes, is a suitable equivalent to petroleum for fine chemicals and fuels production. The complex structure of lignocellulose, however, requires a variety of enzymes in order to degrade its components into their respective building blocks that can be used further for the production of various value added products. This study aimed to isolate bacterial strain with the ability to produce a variety of lignocellulosic enzymes. One bacterial isolate was identified by 16S rRNA gene sequencing and phylogenetic analysis as Bacillus safensis LCX found to have CMCase, xylanase, manganese peroxidase, lignin peroxidase, and laccase activities. The enzymes production was induced by growing Bacillus safensis LCX in solid state fermentation using wheat straw, wheat bran, and corn stover. The activities of enzymes were determined by specific colorimetric assays. This study presents Bacillus safensis LCX as a promising source for lignocellulosic enzymes. These findings can extend the knowledge on agro-food wastes valorization strategies toward a sustainable production of fuels and chemicals.

Keywords: Bacillus safensis LCX, high valued chemicals, lignocellulosic enzymes, solid state fermentation

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1496 Influence of Heliotropium Undulatum on Hepatic Glutathione Conjugating Enzymes System in Acetylhydrazide-Rats

Authors: S. Ameddah, O. Deffa, H. Aissaoui, A. Menad, R. Mekkiou, F. Benayache, S. Benayache

Abstract:

Acetylhydrazide (ACHD) is a metabolite of the anti-tubercular drug isoniazid (INH) that has been implicated in liver damage. This study was designed to evaluate hapatoprotective of n-BuOH extract of Heliotrpium undulatum (HUBE) in ACHD hepatotoxicity in rats. Hepatic damage was induced by administration of ACHD (300 mg/Kg op). The protection was affected by the administration of HUBE (200 mg/Kg op) for 14 days before ACHD administration, caused a decrease in LPO levels and in the transaminase and ALP levels and restored the GSH and its related enzymes (GPx, GST, GR) (50-62 %). Simultaneous administration of HUBE afforded a partial protection in statue of hepatic GSH conjugating enzymes upon administration of ACHD.

Keywords: heliotrpium undulatum, acetylhydrazide, glutathione conjugating enzymes, oxydatif stress, heaptoprotectif effect

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1495 Extracellular Enzymes from Halophilic Bacteria with Potential in Agricultural Secondary Flow Recovery Products

Authors: Madalin Enache, Simona Neagu, Roxana Cojoc, Ioana Gomoiu, Delia Ionela Dobre, Ancuta Roxana Trifoi

Abstract:

Various types of halophilic and halotolerant microorganisms able to be cultivated in laboratory on culture media with a wide range of sodium chloride content are isolated from several salted environments. The extracellular enzymes of these microorganisms showed the enzymatic activity in these spectrums of salinity thus being attractive for several biotechnological processes developed at high ionic strength. In present work, a number of amylase, protease, esterase, lipase, cellulase, pectinase, xilanases and innulinase were identified for more than 50th bacterial strains isolated from water samples and sapropelic mud from four saline and hypersaline lakes located in Romanian plain. On the other hand, the cellulase and pectinase activity were also detected in some halotolerant microorganisms isolated from secondary agricultural flow of grapes processing. The preliminary data revealed that from totally tested strains seven harbor proteases activity, eight amylase activity, four for esterase and another four for lipase, three for pectinase and for one strain were identified either cellulase or pectinase activity. There were no identified enzymes able to hydrolase innulin added to culture media. Several strains isolated from sapropelic mud showed multiple extracellular enzymatic activities, namely three strains harbor three activities and another seven harbor two activities. The data revealed that amylase and protease activities were frequently detected if compare with other tested enzymes. In the case of pectinase were investigated, their ability to be used for increasing resveratrol recovery from material resulted after grapes processing. In this way, the resulted material from grapes processing was treated with microbial supernatant for several times (two, four and 24 hours) and the content of resveratrol was detected by High Performance Liquid Chromatography method (HPLC). The preliminary data revealed some positive results of this treatment.

Keywords: halophilic microorganisms, enzymes, pectinase, salinity

Procedia PDF Downloads 160
1494 Examining Microbial Decomposition, Carbon Cycling and Storage in Cefni Coastal Salt Marsh, Anglesey Island, Wales, United Kingdom

Authors: Dasat G. S., Christopher F. Tim, J. Dun C.

Abstract:

Salt marshes are known to sequester carbon dioxide from the atmosphere into the soil, but natural and anthropogenic activities could trigger the release of large quantities of centuries of buried carbon dioxide, methane and nitrous oxide (CO2, CH4 and N2O) which are the major greenhouse gases (GHGs) implicated with climate change. Therefore, this study investigated the biogeochemical activities by collecting soil samples from low, mid and high zones of the Cefni salt marsh, within the Maltreat estuary, on the island of Anglesey, north Wales, United Kingdom for a consortium of laboratory based experiments using standard operating protocols (POS) to quantify the soil organic matter contents and the rate of microbial decomposition and carbon storage at the Carbon Capture Laboratory of Bangor University Wales. Results of investigations reveals that the mid zone had 56.23% and 9.98% of soil water and soil organic matter (SOM) contents respectively higher than the low and high zones. Phenol oxidase activity (1193.53µmol dicq g-1 h-1) was highest at the low zone in comparison to the high and mid zones (867.60 and 608.74 µmol dicq g-1 h-1) respectively. Soil phenolic concentration was found to be highest in the mid zone (53.25 µg-1 g-1) when compared with those from the high (15.66 µg-1 g-1) and low (4.18 µg-1 g-1) zones respectively. Activities of hydrolase enzymes showed similar trend for the high and low zones and much lower activities in the mid zone. CO2 flux from the mid zone (6.79 ug g-1 h-1) was significantly greater than those from high (-2.29 ug g-1 h-1) and low (1.30 µg g-1 h-1) zones. Since salt marshes provide essential ecosystem services, their degradation or alteration in whatever form could compromise such ecosystem services and could convert them from net sinks into net sources with consequential effects to the global environment.

Keywords: saltmarsh, decomposition, carbon cycling, enzymes

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1493 Study of Individual Parameters on the Enzymatic Glycosidation of Betulinic Acid by Novozyme-435

Authors: A. U. Adamu, Hamisu Abdu, A. A. Saidu

Abstract:

The enzymatic synthesis of 3-O-β-D-glucopyranoside-betulinic acid using Novozyme-435 as a catalyst was studied. The effect of various parameters such as substrate molar ratio, reaction temperature, reaction time, re-used enzymes and amount of enzymes were investigated. The optimum rection conditions for the enzymatic glycosidation of betulinic acid in an organic solvent using Novozym-435 was found to be at 1:1.2 substrate molar ratio, 55oC, 24 h and 180 mg of enzymes with percentage conversion of 88.69 %.

Keywords: betulinic acid, glycosidation, novozyme-435, optimization

Procedia PDF Downloads 395
1492 Microbial Contamination of Haemolymph of Honeybee (Apis mellifera intermissa) Parasitized by Varroa Destructor

Authors: Messaouda Belaid, Salima Kebbouche-Gana

Abstract:

The negative effect of the Varroa bee colony is very important. They cause morphological and physiological changes, causing a decrease in performance of individuals and long-term death of the colony. Indirectly, they weaken the bees become much more sensitive to the different pathogenic organisms naturally present in the colony. This work aims to research secondary infections of microbial origin occurred in the worker bee nurse due to parasitism by Varroa destructor. The feeding behaviour of Varroa may causes damaging host integument. The results show that the microbial contamination enable to be transmitted into honeybee heamocoel are Bacillus sp, Pseudomonas sp, Enterobacter, Aspergillus.

Keywords: honeybee, Apis mellifera intermissa, microbial contamination, Varroa destructor

Procedia PDF Downloads 374
1491 Effect of Select Surfactants on Activities of Soil Enzymes Involved in Nutrient Cycling

Authors: Frieda Eivazi, Nikita L. Mullings

Abstract:

Soils are recipient for surfactants in herbicide formulations. Surfactants entering the soil environment can possibly disrupt different chemical, physical and biological interactions. Therefore, it is critical that we understand the fate, behavior and transport of surfactants upon entering the soil. A comprehensive study was conducted to examine effect of surfactants on nutrient uptake, microbial community, and enzyme activity. The research was conducted in the greenhouse growing corn (Zea mays) as a test plant in a factorial experiment (three surfactants at two different rates with control, and three herbicides) organized as randomized blocked design. Surfactants evaluated were Activator 90, Agri-Dex, and Thrust; herbicides were glyphosate, atrazine, and bentazon. Treatments examined were surfactant only, herbicide only, and surfactant + herbicide combinations. Corn was planted in fertilized soils (silt loam and silty clay) with moisture content maintained at the field capacity for optimum growth. This paper will report results of above mentioned treatments on acid phosphatase, beta-glucosidase, arylsulfatase, beta-glucosaminidase, and dehydrogenase activities. In general, there were variations in the enzyme activities with some inhibition and some being enhanced by the treatments. Activator 90 appeared to have the highest inhibitory effect on enzymatic activities. Atrazine application significantly decreased the activities of acid phosphatase, beta-glucosidase, and dehydrogenase in both soils; however, combination of Atrazine + Agridex increased the acid phosphatase activity while significantly inhibiting the other enzyme activities in soils. It was concluded that long-term field studies are needed to validate changes in nutrient uptake, microbial community and enzyme activities due to surfactant-herbicide combination effects.

Keywords: herbicides, nutrient cycling, soil enzymes, surfactant

Procedia PDF Downloads 219
1490 Contributions of Microbial Activities to Tomato Growth and Yield under an Organic Production System

Authors: O. A. Babalola, A. F Adekunle, F. Oladeji, A. T. Osungbade, O. A. Akinlaja

Abstract:

Optimizing microbiological activities in an organic crop production system is crucial to the realization of optimum growth and development of the crops. Field and pot experiments were conducted to assess soil microbial activities, growth and yield of tomato varieties in response to 4 rates of composted plant and animal residues. The compost rates were 0, 5, 10 and 20 t ha-1, and improved Ibadan and Ibadan local constituted the varieties. Fungi population, microbial biomass nitrogen, cellulase and proteinase activities were significantly higher (P≤ 0.05) at the rhizosphere of the local variety than that of improved variety. This led to a significantly higher number of branches, plant height, leaf area, number of fruits and less days to maturity in the local variety. Furthermore, compost-amended soil had significantly higher microbial populations, microbial biomass N, P and C, enzyme activities, soil N, P and organic carbon than control, but amendment of 20 t ha-1 gave significantly higher values than other compost rates. Consequently, growth parameters and tissue N significantly increased in all compost treatments while dry matter yield and weight of fruits were significantly higher in soil amended with 20 t ha-1. Correlation analysis showed that microbial activities at 6 weeks after transplanting (6 WAT) were more consistently and highly correlated with growth and yield parameters. It was concluded that microbial activities could be optimized to improve the yield of the two tomato varieties in an organic production system, through the application of compost, particularly at 20 t ha-1.

Keywords: compost, microbial activities, microbial contribution, tomato growth and yield

Procedia PDF Downloads 233
1489 FTIR Spectroscopy for in vitro Screening in Microbial Biotechnology

Authors: V. Shapaval, N. K. Afseth, D. Tzimorotas, A. Kohler

Abstract:

Globally there is a dramatic increase in the demand for food, energy, materials and clean water since natural resources are limited. As a result, industries are looking for ways to reduce rest materials and to improve resource efficiency. Microorganisms have a high potential to be used as bio factories for the production of primary and secondary metabolites that represent high-value bio-products (enzymes, polyunsaturated fatty acids, bio-plastics, glucans, etc.). In order to find good microbial producers, to design suitable substrates from food rest materials and to optimize fermentation conditions, rapid analytical techniques for quantifying target bio products in microbial cells are needed. In the EU project FUST (R4SME, Fp7), we have developed a fully automated high-throughput FUST system based on micro-cultivation and FTIR spectroscopy that facilitates the screening of microorganisms, substrates and fermentation conditions for the optimization of the production of different high-value metabolites (single cell oils, bio plastics). The automated system allows the preparation of 100 samples per hour. Currently, The FUST system is in use for screening of filamentous fungi in order to find oleaginous strains with the ability to produce polyunsaturated fatty acids, and the optimization of cheap substrates, derived from food rest materials, and the optimization of fermentation conditions for the high yield of single cell oil.

Keywords: FTIR spectroscopy, FUST system, screening, biotechnology

Procedia PDF Downloads 417