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The aim of the present investigation is to examine the characteristics of diesel engine for varying concentrations of diethyl ether (DEE) as an oxygenated additive in repurpose used cooking oil (RU...

Conventionally, degumming is carried out at 90°C--110°C temperature by boiling the raw silk with Marseilles soap and sodium bicarbonate which eventually requires a lot of water and energy. In this study, degumming of Chinese bivoltine raw silk fibres with alkaline protease produced by Beauveria sp. (MTCC 5184) is studied. Complete degumming was obtained in 45 min with 75 units of enzyme per gram of silk. Degumming was found to be optimal at 50°C and pH 9.0. Scanning electron micrographs showed that the sericin deposits were removed and the obtained fibres were clean, separated, had smooth feel with shine as compared to untreated fibres. Sericin isolated from silk cocoon (by-product which goes waste) was hydrolyzed with the same alkaline protease obtained from Beauveria sp. to get small molecular weight peptides. These peptides can be utilized further for cosmetic, pharmaceutical, and various industrial applications.

The conversion of biobased feedstocks into energy and value-added chemicals is one main approach to address the current global challenge for waste mitigation through the biorefinery mode. Corncob biomass which is one of the most abundant agricultural residue in India with a high hemicellulose content, can serve as a potential low-cost raw material for food-grade xylitol production. The present study demonstrates a process for xylitol production from corncob biomass with detailed energy and life cycle analysis for viability assessment. The major highlight of the process is the use of microbial fermentation, where biomass-derived D-xylose is converted to xylitol with high selectivity. Overall, 0.502 kg of xylitol crystals could be produced from 3.5 kg of corncob biomass. Simulation analysis revealed that the evaporators are the primary consumers of energy, and the process of heat integration can significantly reduce the energy requirements of the overall process. Environmental impacts of the system evaluated showed emission results of 8.68 kg CO2 equivalent and revealed that marine aquatic and freshwater eco-toxicity are the only possible contributors to the environment. The results suggest that the process would have favourable energy balances, which can be used in pilot plant and heat exchanger network design and operation for xylitol production scale up to 500 L.

Alkaline protease secreted by Conidiobolus coronatus has been evaluated extensively in tanneries and finds application in pre-tanning operations in leather manufacture. It is important to produce the enzyme in inexpensive and optimized media on large scale for the process to be commercially viable. The present paper describes optimization of fermentation conditions in shake flasks and scale up of production to 100 L in fermentors. The production is complete in 2–3 days comparable to bacterial fermentations. The organism utilized several carbon sources such as starch, sucrose, lactose, glucose and fructose for production. Soyabean meal at an optimum concentration of 2–3% was found to be best inducer. Diammonium hydrogen phosphate, casamino acids and Hi-media peptone gave activities comparable to yeast extract. Preservation and stabilization studies showed that glycerol conferred considerable stabilization at room temperature while ammonium sulphate precipitated enzyme at 0.9 saturation was best with stability up to 2 years even at room temperature.

Hexavalent chromium (Cr 6+ ) is a common and toxic pollutant in soils and wastewaters. Conversion of the mobile Cr 6+ to less mobile and less toxic trivalent Cr 3+ can be achieved with conventional chemical reduction and its subsequent precipitation. Alternatively, Cr 6+ can also be reduced to Cr 3+ by microorganisms and has potential for application in decontamination of industrial effluents. During our studies on chromium toxicity in actinomycetes, a strain of Streptomyces griseus was found to grow and reduce highly toxic Cr 6+ to less toxic Cr 3+ from media containing 5-60 ppm of Cr 6+ . The concentration of Cr 3+ increased with simultaneous decrease in Cr 6+ during growth with complete conversion in 3-4 days. Reduction was faster when addition of chromium (especially high concentrations of chromium) was done after 24 h growth than at the time of inoculation. Conversion of Cr 6+ to Cr 3+ was complete within 24-48 h of chromium addition with significant uptake in the biomass. Reduction of chromium by resting cells and effect of various factors on chromium reduction are discussed.