A bio-augmented system with Methylosarcina sp. LC-4 immobilized on bio-carriers: Towards an integrated approach to mitigate and valorize methane emissions from landfills to biodiesel.

Bio-augmented systems based on methanotrophs are indispensable in curbing anthropogenic methane emissions from engineered landfills or dumpsites to curtail rising levels of greenhouse gases. Using a defined methanotroph culture immobilized on an inert material-based bio-carrier makes it possible to harness these methane emissions for creating value-added products, thus contributing to the circular bio-economy. The methane oxidation capacity of the model methanotroph Methylosarcina sp.

Organosolv Pretreatment of Sorghum Stalks Using Glycerol.

Glycerol is a promising low-cost solvent for biomass pretreatment since a large amount of glycerol is generated as a by-product in the biodiesel industry. Pretreatment is a method of disintegration of the recalcitrant structure of biomass to enhance the accessibility of cellulose and hemicelluloses to enzymes for complete saccharification. During pretreatment, glycerol breaks the lignin carbohydrate complex and selectively solubilizes lignin.

One pot facile green synthesis of crystalline bio-ZrO nanoparticles using Acinetobacter sp. KCSI1 under room temperature.

In this study, crystalline ZrO nanoparticles were synthesized in one pot at room temperature using an extremophilic Acinetobacter sp. KCSI1 and characterized using various techniques to study its structural, optical and crystalline properties. The average size of the ZrO nanoparticles was found to be 44 ± 7 nm.

Detoxification of hexavalent chromium by Leucobacter sp. uses a reductase with specificity for dihydrolipoamide.

Leucobacter sp. belongs to the metal stressed community and possesses higher tolerance to metals including chromium and can detoxify toxic hexavalent chromium by reduction to less toxic trivalent chromium. But, the mechanism of reduction of hexavalent chromium by Leucobacter sp.

Production of xylooligosaccharides in SSF by Bacillus subtilis KCX006 producing β-xylosidase-free endo-xylanase and multiple xylan debranching enzymes.

Xylanase and xylooligosaccharides (XOS) are employed in food and feed industries. Though xylanase production from lignocellulosic materials (LCMs) by solid-state fermentation (SSF) is well known, the XOS formed during growth is not recovered due to its conversion to xylose by β-xylosidase and subsequent bacterial metabolism. A new strain, Bacillus subtilis KCX006, was exceptionally found to synthesize β-xylosidase-free endo-xylanase and multiple xylan debranching enzymes constitutively in the presence of LCMs.

Hyper-production of alpha-amylase from agro-residual medium with high-glucose in SSF using catabolite derepressed Bacillus subtilis KCC103.

In Bacillus subtilis KCC103, alpha-amylase is hyper-produced and alpha-amylase synthesis is not subject to catabolite repression. The alpha-amylase was produced from KCC103 by solid-state fermentation (SSF) using agro-residues and oil cakes as growth substrates. The KCC103 was also tested for its resistance to repression by hyper level (>10% w/w) of glucose and xylose on alpha-amylase production in SSF.

Enzymatic digestibility and ethanol fermentability of AFEX-treated starch-rich lignocellulosics such as corn silage and whole corn plant.

Background: Corn grain is an important renewable source for bioethanol production in the USA. Corn ethanol is currently produced by steam liquefaction of starch-rich grains followed by enzymatic saccharification and fermentation. Corn stover (the non-grain parts of the plant) is a potential feedstock to produce cellulosic ethanol in second-generation biorefineries.

Alkali-based AFEX pretreatment for the conversion of sugarcane bagasse and cane leaf residues to ethanol.

Sugarcane is one of the major agricultural crops cultivated in tropical climate regions of the world. Each tonne of raw cane production is associated with the generation of 130 kg dry weight of bagasse after juice extraction and 250 kg dry weight of cane leaf residue postharvest. The annual world production of sugarcane is approximately 1.

Mixture optimization of six core glycosyl hydrolases for maximizing saccharification of ammonia fiber expansion (AFEX) pretreated corn stover.

In this work, six core glycosyl hydrolases (GH) were isolated and purified from various sources to help rationally optimize an enzyme cocktail to digest ammonia fiber expansion (AFEX) treated corn stover. The four core cellulases were endoglucanase I (EG I, GH family 7B), cellobiohydrolase I (CBH I, GH family 7A), cellobiohydrolase II (CBH II, GH family 6A) and beta-glucosidase (betaG, GH family 3). The two core hemicellulases were an endo-xylanase (EX, GH family 11) and a beta-xylosidase (betaX, GH family 3).

Use of a new catabolite repression resistant promoter isolated from Bacillus subtilis KCC103 for hyper-production of recombinant enzymes.

Bacillus subtilis KCC103 hyper-produces alpha-amylase and the synthesis is resistant to carbon catabolite repression. The strain efficiently produced alpha-amylase in low cost agro-biomass based medium rich in simple sugars without catabolite repression. Here, the catabolite repression resistant promoter (amyR4) of alpha-amylase was isolated from KCC103 and used to synthesize recombinant enzymes in B.

Optimization of biobleaching of paper pulp in an expanded bed bioreactor with immobilized alkali stable xylanase by using response surface methodology.

Purified alkali stable xylanase from Aspergillus fischeri was immobilized on polystyrene beads using diazotization method. An expanded bed bioreactor was developed with these immobilized beads to biobleach the paper pulp in continuous mode. Response surface methodology was applied to optimize the biobleaching conditions.

Comparison of in vitro Cr(VI) reduction by CFEs of chromate resistant bacteria isolated from chromate contaminated soil.

Chromate resistant and reducing strains were isolated from chromium contaminated soil and identified as Bacillus sp. (KCH2 and KCH3), Leucobacter sp. (KCH4) and Exiguobacterium sp.

Alpha-amylase production from catabolite derepressed Bacillus subtilis KCC103 utilizing sugarcane bagasse hydrolysate.

A catabolite derepressed Bacillus subtilis strain KCC103 was used to produce alpha-amylase in medium containing sugarcane bagasse hydrolysate (SBH). Addition of SBH (1% reducing sugar (w/v)) to the nutrient medium supported maximum alpha-amylase production of 67.4 Um l(-1).

Purification and characterization of a maltooligosaccharide-forming alpha-amylase from a new Bacillus subtilis KCC103.

A maltooligosaccharide-forming alpha-amylase was produced by a new soil isolate Bacillus subtilis KCC103. In contrast to other Bacillus species, the synthesis of alpha-amylase in KCC103 was not catabolite-repressed. The alpha-amylase was purified in one step using anion exchange chromatography after concentration of crude enzyme by acetone precipitation.