T.S. Chandra

Bio: T.S. Chandra is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Eleusine & Xylanase. The author has an hindex of 27, co-authored 67 publications receiving 2395 citations. Previous affiliations of T.S. Chandra include Indian Institutes of Technology & Indian Institute of Science.

A novel cold-tolerant Clostridium strain PXYL1 isolated from a psychrophilic cattle manure digester that secretes thermolabile xylanase and cellulase

Abstract: A Clostridium strain PXYL1 was isolated from a cold-adapted cattle manure biogas digester at 15°C. It could grow at temperatures as low as 5°C up to 50°C with highest specific growth rate at 20°C and is a psychrotroph. It produced extracellular hydrolytic enzymes namely xylanase, endoglucanase, β-xylosidase, β-glucosidase and filter paper cellulase, all of which had maximal activity at 20°C. The induction of xylanase was highest on birch wood xylan (37 IU(mg protein)−1) compared with xylose (1.11 IU(mg protein)−1), cellobiose (1.43 IU(mg protein)−1) and glucose (no activity). The xylanase was thermolabile with a half-life of 30 min at 40°C and 8 min at 50°C but stable for over 2 h at 20°C. The crude enzyme released reducing sugars (1.25 g l−1) from finger millet flour at 20°C, while commercial food-grade xylanases showed no hydrolysis at this temperature. This is the first report of a Clostridium strain growing at 20°C and producing an array of xylanolytic and cellulolytic enzymes, possessing low temperature optima of 20°C, which may facilitate degradation of plant fibre under low-temperature conditions.

A cellulase-free xylanase from alkali-tolerantAspergillus fischeri Fxn1

Abstract: An alkali-tolerant fungusAsperqillus fischeri Fxn1 isolated from xylan enrichment grew in the pH range 5–10 and secreted an extracellular cellulase-free xylanase. Arabinose, lactose, maltose, cellobiose and glucose induced low levels of xylanase (1.8–9.0 IU/ml), whereas xylose, xylan and wheat bran induced higher level (34–45 IU/ml).CMcellulose and FPcellulose did not support growth. The optimum pH of xylanase was 6.0–6.5 and it was stable in a wide range of pH 5–9.5. The optimum temperature was 60°C and it was stable upto 55°C. The half-lives at 50 and 55 °C were 240 and 40 min. respectively. This enzyme released reducing sugars from pulp at pH 9.0 and 40°C.

Oxalate, formate, formamide, and methanol metabolism in Thiobacillus novellus.

Abstract: Thiobacillus novellus was able to grow with oxalate, formate, formamide, and methanol as sole sources of carbon and energy. Extensive growth on methanol required yeast extract or vitamins. Glyoxylate carboligase was detected in extracts of oxalate-grown cells. Ribulose bisphosphate carboxylase was found in extracts of cells grown on formate, formamide, and thiosulfate. These data indicate that oxalate is utilized heterotrophically in the glycerate pathway, and formate and formamide are utilized autotrophically in the ribulose bisphosphate pathway. Nicotinamide adenine dinucleotide-linked formate dehydrogenase was present in extracts of oxalate-, formate-, formamide-, and methanol-grown cells but was absent in thiosulfate- and acetate-grown cells.

Xylanases, xylanase families and extremophilic xylanases

Abstract: Xylanases are hydrolytic enzymes which randomly cleave the β 1,4 backbone of the complex plant cell wall polysaccharide xylan. Diverse forms of these enzymes exist, displaying varying folds, mechanisms of action, substrate specificities, hydrolytic activities (yields, rates and products) and physicochemical characteristics. Research has mainly focused on only two of the xylanase containing glycoside hydrolase families, namely families 10 and 11, yet enzymes with xylanase activity belonging to families 5, 7, 8 and 43 have also been identified and studied, albeit to a lesser extent. Driven by industrial demands for enzymes that can operate under process conditions, a number of extremophilic xylanases have been isolated, in particular those from thermophiles, alkaliphiles and acidiphiles, while little attention has been paid to cold-adapted xylanases. Here, the diverse physicochemical and functional characteristics, as well as the folds and mechanisms of action of all six xylanase containing families will be discussed. The adaptation strategies of the extremophilic xylanases isolated to date and the potential industrial applications of these enzymes will also be presented.

Microbial xylanases and their industrial applications: a review.

Abstract: Despite an increased knowledge of microbial xylanolytic systems in the past few years, further studies are required to achieve a complete understanding of the mechanism of xylan degradation by microorganisms and their enzymes. The enzyme system used by microbes for the metabolism of xylan is the most important tool for investigating the use of the second most abundant polysaccharide (xylan) in nature. Recent studies on microbial xylanolytic systems have generally focussed on induction of enzyme production under different conditions, purification, characterization, molecular cloning and expression, and use of enzyme predominantly for pulp bleaching. Rationale approaches to achieve these goals require a detailed knowledge of the regulatory mechanism governing enzyme production. This review will focus on complex xylan structure and the microbial enzyme complex involved in its complete breakdown, studies on xylanase regulation and production and their potential industrial applications, with special reference to biobleaching.

A review on nanofluids: preparation, stability mechanisms, and applications

Abstract: Nanofluids, the fluid suspensions of nanomaterials, have shown many interesting properties, and the distinctive features offer unprecedented potential for many applications. This paper summarizes the recent progress on the study of nanofluids, such as the preparation methods, the evaluation methods for the stability of nanofluids, and the ways to enhance the stability for nanofluids, the stability mechanisms of nanofluids, and presents the broad range of current and future applications in various fields including energy and mechanical and biomedical fields. At last, the paper identifies the opportunities for future research.

Phenolics in food and nutraceuticals

Abstract: Phenolics in Food and Nutraceuticals is the first single-source compendium of essential information concerning food phenolics. This unique book reports the classification and nomenclature of phenolics, their occurrence in food and nutraceuticals, chemistry and applications, and nutritional and health effects. In addition, it describes antioxidant activity of phenolics in food and nutraceuticals as well as methods for analysis and quantification. Each chapter concludes with an extensive bibliography for further reading. Food scientists, nutritionists, chemists, biochemists, and health professionals will find this book valuable.