Akshaya Gupte

Solid state fermentation of lignocellulosic waste for cellulase and β-glucosidase production by cocultivation of Aspergillus ellipticus and Aspergillus fumigatus

Lignocellulosic wastes available in abundance can be excellent substrates for the production of cellulase and β‐glucosidase enzymes by solid state fermentation (SSF) . A cellulase system, showing enhanced hydrolytic potential and β‐glucosidase under SSF, was obtained by cocultivation of Aspergillus ellipticus and Aspergillus fumigatus. Different types of substrates and various pretreatments were used to improve hydrolytic process. Among the various substrates examined, sugarcane bagasse gave the highest activity and 2% calcium hydroxide treatment was found to be the most favorable treatment for the enzyme production. The maximum enzyme production was obtained on the eighth day of the fermentation process.

Optimization of media components for laccase production by litter dwelling fungal isolate Fusarium incarnatum LD‐3

Laccase production by solid state fermentation (SSF) using an indigenously isolated litter dwelling fungus Fusarium incarnatum LD‐3 was optimized. Fourteen medium components were screened by the initial screening method of Plackett‐Burman. Each of the components was screened on the basis of ‘p’ (probability value) which was above 95% confidence level. Ortho‐dianisidine, thiamine HCl and CuSO4 · 5 H2O were identified as significant components for laccase production. The Central Composite Design response surface methodology was then applied to further optimize the laccase production. The optimal concentration of these three medium components for higher laccase production were (g/l): CuSO4 · 5 H2O, 0.01; thiamine HCl, 0.0136 and ortho‐dianisidine, 0.388 mM served as an inducer. Wheat straw, 5.0 g was used as a solid substrate. Using this statistical optimization method the laccase production was found to increase from 40 U/g to 650 U/g of wheat straw, which was sixteen times higher than non optimized medium. This is the first report on statistical optimization of laccase production from Fusarium incarnatum LD‐3. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Production of cellulolytic enzymes by coculturing of Aspergillus ellipticus and Aspergillus fumigatus grown on bagasse under solid state fermentation

Production of cellulolytic enzymes on bagasse under solid state fermentation by coculture ofAspergillus ellipticus andAspergillus fumigatus was studied. Cocultivation ofA. ellipticus andA. fumigatus showed improved hydrolytic and Β-glucosidase activities as compared to the occasions when they were used separately. Various pretreatment methods were used to make cellulose accessible to enzymatic attack. Best results were obtained through pretreatment with 2% (w/v) calcium hydroxide. Maximum enzyme production was obtained after 8 d of fermentation process.

Toxicity analysis of azo Red BS and Methyl Red dye solutions on earthworm (Pheretima phosthuma), micro-organisms, and plants

Abstract Azo dyes containing effluent from various textile industries adversely affects water resources, soil fertility, aquatic organisms as well as animals. Pure cultures of bacteria or bacterial consortia have been successfully applied for the biodegradation of toxic dye effluents. In this view, toxicity analysis of Red BS and Methyl Red dyes and their biologically decolorized solutions were studied on earthworm (Pheretima phosthuma), plants, and micro-organisms. Different types of morphological symptoms were observed upon exposure of dye solutions on earthworm. Mortality rate in terms of LD50 value was determined for both the dye solutions. The LD50 of untreated Red BS and Methyl Red dye solution was 120.22 and 218.77 mg l−l, respectively. Alteration in the protein content was observed in various organs, head, clitella, and abdomen of earthworms on exposure of dye solutions and the presence of proteins under stress condition was studied using Sodium dodecyl sulphate-Polyacrylamide Gel Electrophoresis....

Bioremediation of Polycyclic Aromatic Hydrocarbon (PAHs): A Perspective

Hydrocarbon pollution is a perennial problem not only in India but throughout the globe. A plethora of microorganisms have been reported to be efficient degraders of these recalcitrant pollutants. One of the major concerns of environmental problem is the presence of hydrocarbons due to the various anthropogenic activities. PAHs are ubiquitous in nature i.e. present in soil, water and air. Presence of PAHs in environment creates problem as their presence have deleterious effect on human and animals. They also have the ability to cause the tumors in human and animals. Some of the microorganisms are capable of transforming and degrading these PAHs and remove them from the environment. The present review describes about the sources, structure, fate and toxicity of PAHs as well as different bioremediation techniques involved in the removing of contaminants from the environment which are efficient and cost-effective. The conventional approaches used for removal of PAH are not only environment friendly but also are able to reduce the risk to human and ecosystem.

Laccases: The Biocatalyst with Industrial and Biotechnological Applications

Laccases (Benzenediol: oxygen oxidoreductase, E.C. 1.10.3.2) are enzymes belonging to the group of polyphenol oxidases which are monomeric, dimeric or tetrameric glycoproteins with copper atoms per monomer located at the catalytic site. It is widely distributed in wood rotting fungi and which is also found in a variety of molds, insects as well as some plants and bacteria. Laccases have received much attention from researchers in the last decades due to their ability to oxidize both phenolic and non phenolic lignin related compounds as well as highly recalcitrant environmental pollutants, which makes them very useful for their application to several biotechnological processes. As on oxidase, laccase is used in many agricultural, industrial and medicinal applications. Thus, laccases are increasingly finding applications in biotechnology in the fields of environment-friendly synthesis of fine chemicals and for the gentle derviatization of biologically active compounds e.g. antibiotics, amino acids, antioxidants and cytostatics. Oligomerization and polymerization reactions can lead to new homo- or heteropolymers and biomaterials. These may be useful in wide range of applications including the production of polymers with antioxidative properties, the co-polymerizing of lignin components with low molecular mass compounds, the coating of cellulosic cotton fibers or wool, ingredients of cosmetics. Laccase nano particles have also been used for the elimination of micropollutants from waste water in bioreactors.