Browsing by Author "Singh, Bijender"

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    Enhanced endoxylanase production by Myceliophthora thermophila with applicability in saccharification of agricultural substrates
    (3 Biotech, 2019) Dahiya, Seema; Singh, Bijender
    The production of enzymes by solid-state fermentation is an interesting process and currently used worldwide as it can be carried out in solid matrix in absence of free water. In present study, Myceliophthora thermophila BJTLRMDU3 produced high titres of endoxylanase (890.55 U/g DR, dry residue) using 5 g rice straw at pH 7.0 and at 45 °C with 1:7 (w/v) solid-to-moisture ratio with inoculum rate of 12 × 106 spores/ml after 4 days in solid-state fermentation. High enzyme titre was produced after moistening the rice straw with solution containing ammonium sulphate (0.4%), K2HPO4 (1.0%), MgSO4 ·7H2O (0.3%), FeSO4 ·7H2O (0.03%) and CaCl2 (0.03%). Addition of sucrose (2% w/v) and ammonium nitrate (2% w/v) further enhanced the endoxylanase production. A high endoxylanase production was achieved at water activity (aW) of 0.95 (1639.80 U/g DR) that declined drastically below this value. Among different surfactants, Tween 20 (3% v/v) enhanced the secretion of endoxylanase (2047.91 U/g DR). Furthermore, on optimization of K2HPO4 concentration, it was found that 0.5% K2HPO4 improved (2191.28 U/g DR) endoxylanase production and overall 4.35-folds increase in production of endoxylanase was achieved after optimization of culture conditions. The enzyme has potential to liberate monomeric (xylose) as well as oligomeric (xylotiose, xylotetrose, and xylopantose) sugars from xylan. On saccharification of rice straw and corncob with endoxylanase, maximum yield of reducing sugars was 135.61 and 132.61 mg/g of substrate recorded after 48, and 36 h, respectively.
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    Probiotics, prebiotics and synbiotics: Safe options for next-generation therapeutics
    (Applied Microbiology and Biotechnology, 2022) Singh, Bijender
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    Simple and solvent free practical procedurefor chalcones: An expeditious, mild andgreener approach
    (Current Research in Green and Sustainable Chemistry, 2020) Adnan, Duha; Singh, Bijender; Mehta, Surinder,Kumar; Kumar, Vinod; Kataria, Ramesh
    An extremely simple, expeditious and greener synthetic method for a variety of chalcone derivatives (3) under mild and solvent free reaction conditions has been developed. The present protocol discloses the use of p-toluenesulfonic acid (p-TSA) as a solid phase organocatalyst which accelerates the Claisen–Schmidt condensation reaction dramatically under mild conditions. Various aryl aldehydes (1) were treated with differently substituted aryl ketones (2) in the presence of p-TSA at 50–60 C to yield the desired products in a very short period of reaction time. Mild reaction conditions, clean reaction media, expulsion of hazardous solvents, simple work-up, exclusive formation of products in high yields without side products, and easy purification are advantages of the present methodology.