Extra Cellular Endoxylanase Production from Solid State Fermentation of Dried Grass by Streptomyces sp OM 09

The present study deals with the cost effective production of endoxylanase by a strain of Streptomyces sp, isolated from soil of Kanha National park and Tiger Reserve, India. Among various agricultural residues used in the solid state fermentation media, grass followed by rice straw proved to be the best carbon source for the growth and production of extracellular endoxylanase by the strain. Drying of the grass improved the enzyme production and best enzyme production was obtained at a concentration of 1%. Highest endoxylanase production was found at pH 6.0 and at 37°C. The kinetics of growth and enzyme production showed that highest enzyme production could be achieved within 48 hours of cultivation. The endoxylanase produced, after partial purification showed highest activity at 60°C and at pH 6.0.The enzyme showed moderate thermostability and stability at a pH range of 5.0- 8.5 and a substrate specificity towards xylan only. The improvement of enzyme activity in presence of thiol compounds indicated the presence of thiol group at the active site of the enzyme.ÂÂ

A Statistical Approach for Optimization of Simultaneous Production of β-Glucosidase and Endoglucanase by Rhizopus oryzae from Solid-State Fermentation of Water Hyacinth Using Central Composite Design

The production cost of β-glucosidase and endoglucanase could be reduced by using water hyacinth, an aquatic weed, as the sole carbon source and using cost-efficient fermentation strategies like solid-state fermentation (SSF). In the present study, the effect of different production conditions on the yield of β-glucosidase and endoglucanase by Rhizopus oryzae MTCC 9642 from water hyacinth was investigated systematically using response surface methodology. A Central composite experimental design was applied to optimize the impact of three variables, namely, substrate concentration, pH, and temperature, on enzyme production. The optimal level of each parameter for maximum enzyme production by the fungus was determined. Highest activity of endoglucanase of 495 U/mL was achieved at a substrate concentration of 1.23%, pH 7.29, and temperature 29.93°C whereas maximum β-glucosidase activity of 137.32 U/ml was achieved at a substrate concentration of 1.25%, pH 6.66, and temperature 32.09°C. There was a direct correlation between the levels of enzymatic activities and the substrate concentration of water hyacinth as carbon source

Characterization of Raw Starch Digesting and Adsorbing Extra Cellular Isoamylase from Rhizopus oryzae

The partially purified extra cellular isoamylase produced by Rhizopus oryzae PR7 MTCC 9642, was characterized for various parameters. It showed highest affinity towards oyster glycogen followed by starch and amylopectin. The temperature and pH optima were found to be at 55° C and 5 respectively. The enzyme was found to be stable at 55°C for 10 minutes and at a broad pH range of 4-8. Increase in stability in presence of thiol additives and deactivation in presence of thiol inhibitors indicated the existence of thiol groups at the active site of the enzyme. The enzyme could digest raw native starches collected from various wastes of which rice extract and bread dust showed the highest extent of saccharification. Glucose and maltose were the major end products of starch bioconversion by the isoamylase. The isoamylase was found to be adsorbed onto various raw starch molecules, the rate of adsorption and desorption was best onto corn starch molecules

Production of Extra Cellular Exoglucanase by Rhizopus oryzae from Submerged Fermentation of Agro Wastes

Rhizopus oryzae PR7 MTCC 9642, a producer of endoglucanse was found to produce extra cellular exoglucanase or avicelase when grown on avicel or micro crystalline cellulose. In order to curtail the cost of production the strain was grown in media supplemented with various cellulosic wastes, of which dried flower showed the best result followed by the sweet lime peel at optimum pH 8.0 and 5.0 respectively at 37° C. Peptone was found to be the best nitrogen source for exoglucanase production whereas amongst metal ions Mn2+ and Fe2+ could bring a 1.23 fold increase in enzyme production in sweet lime peel supplemented culture. Under optimized condition, highest exoglucanse production was achieved at 96 hours of growth. The enzyme showed optimum activity at pH 5.0 and 40°C and stability at pH range of 5-9 and about 90% activity was retained even after an exposure of 10 minutes at 80° C. The enzyme activity was enhanced in presence of Mn2+ and Fe2. The enzyme was found to saccharify avicel and the wastes into cellobiose

Optimization of Endoglucanase Production in Liquid State Fermentation from Waterhyacinth by Rhizopus oryzae Using Response Surface Methodology

Abstract: Statistically based experimental design were applied for the optimization of endoglucanase production in liquid state fermentation by Rhizopus oryzae MTCC 9642 using water hyacinth as sole carbon source. Effect of three critical culture parameters substrate concentration, cultivation temperature and pH on enzyme production, examined by Response Surface Methodology using Central Composite Design(CCD) indicated that although a substrate concentration of 1.25% was essential to maximize the production of the enzyme by the strain , but the combination of pH 6 and 40 0 C temperature were required for highest production of endoglucanase. Under the optimized cultivation condition the strain synthesized 450 IU/ml for endoglucanase utilizing water hyacinth in the media. A verification experiment was accomplished and revealed approximately 95% model validity

In situ and ex situ bioremediation of heavy metals: the present scenario

Enhanced population growth, rapid industrialization, urbanization and hazardous industrial practices have resulted in the development of environmental pollution in the past few decades. Heavy metals are one of those pollutants that are related to environmental and public health concerns based on their toxicity. Effective bioremediation may be accomplished through “ex situ” and “in situ” processes, based on the type and concentration of pollutants, characteristics of the site but is not limited to cost. The recent developments in artificial neural network and microbial gene editing help to improve “in situ” bioremediation of heavy metals from the polluted sites. Multi-omics approaches are adopted for the effective removal of heavy metals by various indigenous microbes. This overview introspects two major bioremediation techniques, their principles, limitations and advantages, and the new aspects of nanobiotechnology, computational biology and DNA technology to improve the scenario

Immobilized enzymes as potent antibiofilm agent

Biofilm has been a point of concern in hospitals and various industries. They not only cause various chronic infections but are also responsible for the degradation of various medical appliances. Since the last decade, various alternate strategies are being adopted to combat the biofilm formed on various biotic and abiotic surfaces. The use of enzymes as a potent anti-fouling agent is proved to be of utmost importance as the enzymes can inhibit biofilm formation in an eco-friendly and cost-effective way. The physical and chemical immobilization of the enzyme not only leads to the improvement of thermostability and reusability of the enzyme, but also gains better efficiency of biofilm removal. Immobilization of amylase, cellobiohydrolase, pectinase, subtilisin A and β-N-acetyl-glucosaminidase (DspB) are proved to be most effective in inhibition of biofilm formation and removal of matured biofilm than their free forms. Hence, these immobilized enzymes provide greater eradication of biofilm formed on various surfaces and are coming up to be the potent antibiofilm agent.Universidade de Vigo/CISU

Valorisation of CO 2 into Value-Added Products via Microbial Electrosynthesis (MES) and Electro-Fermentation Technology

Microbial electrocatalysis reckons on microbes as catalysts for reactions occurring at electrodes. Microbial fuel cells and microbial electrolysis cells are well-known in this context; both prefer the oxidation of organic and inorganic matter for producing electricity. Notably, the synthesis of high energy-density chemicals (fuels) or their precursors by microorganisms using bio-cathode to yield electrical energy is called Microbial Electrosynthesis (MES), giving an exceptionally appealing novel way for producing beneficial products from electricity and wastewater. This review accentuates the concept, importance and opportunities of MES, as an emerging discipline at the nexus of microbiology and electrochemistry. Production of organic compounds from MES is considered as an effective technique for the generation of various beneficial reduced end-products (like acetate and butyrate) as well as in reducing the load of CO2 from the atmosphere to mitigate the harmful effect of greenhouse gases in global warming. Although MES is still an emerging technology, this method is not thoroughly known. The authors have focused on MES, as it is the next transformative, viable alternative technology to decrease the repercussions of surplus carbon dioxide in the environment along with conserving energy

Microbiomics for enhancing electron transfer in an electrochemical system

In microbial electrochemical systems, microorganisms catalyze chemical reactions converting chemical energy present in organic and inorganic molecules into electrical energy. The concept of microbial electrochemistry has been gaining tremendous attention for the past two decades, mainly due to its numerous applications. This technology offers a wide range of applications in areas such as the environment, industries, and sensors. The biocatalysts governing the reactions could be cell secretion, cell component, or a whole cell. The electroactive bacteria can interact with insoluble materials such as electrodes for exchanging electrons through colonization and biofilm formation. Though biofilm formation is one of the major modes for extracellular electron transfer with the electrode, there are other few mechanisms through which the process can occur. Apart from biofilm formation electron exchange can take place through flavins, cytochromes, cell surface appendages, and other metabolites. The present article targets the various mechanisms of electron exchange for microbiome-induced electron transfer activity, proteins, and secretory molecules involved in the electron transfer. This review also focuses on various proteomics and genetics strategies implemented and developed to enhance the exo-electron transfer process in electroactive bacteria. Recent progress and reports on synthetic biology and genetic engineering in exploring the direct and indirect electron transfer phenomenon have also been emphasized