Dharm Dutt

Performance of a double-basin solar still in the presence of dye

This paper presents the transient behaviour of a double-basin solar still with dye present in the basin water. The effects of various parameters like upper and lower basin water mass, absorptivity of lower basin water with dye, etc. have been studied. Numerical computations were carried out for a typical hot day, 11 May 1987, at New Delhi. On the basis of the numerical results, it is observed that the performance of the system is better when dye is added to the water compared with that without dye.

Production of high level of cellulase-poor xylanases by wild strains of white-rot fungus Coprinellus disseminatus in solid-state fermentation.

The production, optimisation and partial characterisation of xylanases from newly isolated wild strains of Coprinellus disseminatus was performed in solid-state fermentation. Strains SH-1 and SH-2 showed high xylanase (727.78 and 227.99 IU/mL) with very low CMCase (0.925 and 0.660 IU/mL) and laccase (0.640 and 0.742 U/mL) activities at incubation time seven days, 37 degrees C and initial pH 6.4, using yeast extract as nitrogen source and cheap substrate (wheat bran), which increased the cost effectiveness of the process. Crude cellulase-poor xylanases obtained from test strains showed maximum activities at 55 degrees C and pH 6.4 and retained 32.64 (SH-1) and 35.03% (SH-2) activity at pH 8 and 43.01 (SH-1) and 25.00% (SH-2) activity at 65 degrees C. As test strains produced high level of cellulase-poor xylanases, which were active over a wide range of temperature and pH, these enzymes might be used as pulp biobleaching agents.

Improved design of a double effect solar still

Abstract A simple transient analysis of a solar still is presented incorporating the effect of water flowing over the glass cover. An idea of utilizing the evaporated mass of the water flowing over the glass cover has been suggested and investigated. The effects of other system parameters, like addition of dye, basin water mass and basin liner absorptivity, have also been studied. It is observed that the flow of water over the glass cover enhances the still productivity remarkably and also flowing water at a very low rate and collection of condensed vapour is always advisable to obtain comparably much more distillate output.

Bio-conventional bleaching of wheat straw soda-AQ pulp with crude xylanases from SH-1 NTCC-1163 and SH-2 NTCC-1164 strains of Coprinellus disseminatus to mitigate AOX generation.

Two novel cellulase-poor xylanases from Coprinellus disseminatus SH-1 NTCC-1163 (enzyme-A) and SH-2 NTCC-1164 (enzyme-B) produced under solid-state fermentation mitigated kappa number of wheat straw soda-AQ pulps by 24.38 and 27.94% respectively after XE stages. The release of reducing sugars and chromophores was highest for both the enzymes at 10IU/g and reaction time 180min for 55°C at variable consistencies that is, 10% for enzyme-A and 5% for enzyme-B. (A)XECEHH and (B)XECEHH sequences improved brightness by 5.17 and 2.58% respectively at 4.5% chlorine charge. AOX in (A)XECEHH and (B)XECEHH sequences reduced by 56.11 and 55.75% respectively at 4.5% chlorine charge and 68.34 and 67.98% respectively at 2.25% chlorine charge respectively compared to control. Both the enzymes showed improvement in double fold and tear index with a decrease in burst and tensile index. SEM showed peeling, cracking and delamination in fibers due to enzyme treatment thus facilitating the penetration of bleach chemicals.

Biotechnological Transformation of Lignocellulosic Biomass in to Industrial Products: An Overview

Lignocellulose—a major component of biomass available on earth is a renewable and abundantly available with great potential for bioconversion to value-added bio-products. The review aims at physio-chemical features of lignocellulosic biomass and composition of different lignocellulosic materials. This work is an overview about the conversion of lignocellulosic biomass into bio-energy products such as bio-ethanol, 1-butanol, bio-methane, bio-hydrogen, organic acids including citric acid, succinic acid and lactic acid, microbial polysaccharides, single cell protein and xylitol. The biotechnological aspect of bio-transformation of lignocelluloses research and its future prospects are also discussed.

Production of crude enzyme from Aspergillus nidulans AKB-25 using black gram residue as the substrate and its industrial applications

The production of crop residues in India is estimated to be about 500–550 million tons annually. It is estimated that about 93 million tons of crop residues is burnt annually which is not only wastage of valuable biomass resources but pollution of the environment with the production of green house gases also. Among different low cost crop residues, black gram residue as the substrate produced maximal endoglucanase, FPase, and β-glucosidase activities from Aspergillus nidulans AKB-25 under solid-state fermentation. During optimisation of cultural parameters A. nidulans AKB-25 produced maximal endoglucanase (152.14 IU/gds), FPase (3.42 FPU/gds) and xylanase (2441.03 IU/gds) activities. The crude enzyme was found effective for the saccharification of pearl millet stover and bio-deinking of mixed office waste paper. The crude enzyme from A. nidulans AKB-25 produced maximum fermentable sugars of 546.91 mg/g from alkali-pretreated pearl millet stover by saccharification process at a dose of 15 FPU/g of substrate. Pulp brightness and deinking efficiency of mixed office waste paper improved by 4.6% and 25.01% respectively and mitigated dirt counts by 74.70% after bio-deinking. Physical strength properties like burst index, tensile index and double fold number were also improved during bio-deinking of mixed office waste paper.

Rice straw fermentation by Schizophyllum commune ARC-11 to produce high level of xylanase for its application in pre-bleaching

Rice straw is valuable resource that has been used as substrate for cost effective production of xylanase under solid-state fermentation by a newly isolated white rot fungi, S. commune ARC-11. Out of eleven carbon sources tested, rice straw was found most effective for the induction of xylanase that produced 4288.3 IU/gds of xylanase by S. commune ARC-11. Maximum xylanase production (6721.9 IU/gds) was observed on 8th day of incubation at temperature (30 °C), initial pH (7.0) and initial moisture content (70.0%). The supplementation of ammonium sulphate (0.08% N, as available nitrogen) enhanced the xylanase production up to 8591.4 IU/gds. The xylanase production by S. commune ARC-11 was further improved by the addition of 0.10%, (w/v) of Tween-20 as surfactant. The maximum xylanase activities were found at pH 5.0 and temperature 55 °C with a longer stability (180 min) at temperature 45, 50 and 55 °C. This xylanase preparation was also evaluated for the pre-bleaching of ethanol-soda pulp from Eulaliopsis binata. An enzyme dosage of 10 IU/g of xylanase resulted maximum decrease in kappa number (14.51%) with a maximum improvement 2.9% in ISO brightness compared to control.

Exploitation of Parthenium hysterophorous biomass as low-cost substrate for cellulase and xylanase production under solid-state fermentation using Talaromyces stipitatus MTCC 12687

Abstract To make the enzyme production process appreciably inexpensive in respect of SSF, use of economical substrates is of great interest. Out of total eight employed solid substrate, Parthenium hysterophorous biomass exhibited its potential and displayed maximum endoglucanase (30 IU/gds), xylanase (582 IU/gds) and FPase (2.86 FPU/gds) activities. During optimization of cultural parameters, Talaromyces stipitatus MTCC 12687 produced maximum endoglucanase (53.3 IU/gds), FPase (4.51 FPU/gds) and β-glucosidase (62.6 IU/gds) at temperature (30°C), incubation time (5th day), pH (6.0) and moisture content (80%) with the supplementation of peptone as the nitrogen source and Tween-80 as the surfactant under SSF conditions. During the process of optimization different enzyme activities viz. endoglucanase, xylanase, FPase and β-glucosidase were enhanced by approximately 2.0, 1.54, 2.0 and 2.7 fold respectively compared to their respective controls. Talaromyces stipitatus MTCC 12687 enzymes hydrolysed untreated and organosolve pretreated P.hysterophorous biomass to release 93±3.87 and734±17mg/g of reducing sugars respectively after hydrolysis time of 48h.