Enhanced production and application of acidothermophilic Streptomyces cellulase.

An efficient cellulolytic and acidothermophilic actinobacterium was isolated from soil, adhered to decomposing tree bark and was identified as Streptomyces DSK59. Screening of synthetic media and the media components identified that, a medium based on starch casein minerals containing carboxy methyl cellulose (CMC) and beef extract (BE) could support enhanced cellulase production by the organism. CMC, BE, NaCl, temperature and pH were accounted as significant for cellulase production and these were optimized using a response surface central composite design (CCD). Optimization of cellulase production resulted in an enhancement of endoglucanase activity to 27IUml(-1). Acidothermophillic Streptomyces cellulase was found to be efficient for hydrolysis of pretreated sorghum stover and liberated 0.413gg(-1) of total reducing sugars which was higher than previously reported sugar yields obtained using fungal enzymes.

Utilization of silkworm litter and pupal waste-an eco-friendly approach for mass production of Bacillus thuringiensis.

The objective of the present study was to investigate the utilization of pupal waste and silkworm litter separately as production media for the mass cultivation of the potential biopesticide, Bacillus thuringiensis (Bt). Bt is the most successful commercial biopesticide accounting for 90% of all biopesticides sold all over the world. Biochemical analysis of the dry pupal waste revealed to be consisting of 4% carbohydrates, 44.9% proteins and 40% lipids. Similarly the biochemical composition of dry silkworm litter was found to be 4% carbohydrates, 57.5% proteins and 30.5% lipids. B. thuringiensis NCIM No. 2159 was mass cultivated in a semi-solid-state fermentation at a pH 7.0 and temperature 32°C. Changes in the pH and biochemical composition of the substrates were evaluated during the course of the fermentation. The reliability of the two substrates as production media was evaluated by determination of growth at regular intervals. Maximum growth was recorded at 96h incubation showing a spore count in the order of 3.5×10(10) and 3.0×10(10)CFU/g in pupal waste and silkworm litter respectively.

Optimization of process for the production of fungal pectinases from deseeded sunflower head in submerged and solid-state conditions.

Pectinase production studies were carried out in submerged and solid-state conditions from deseeded sunflower head employing Aspergillus niger. The two potential strains of A. niger, DMF 27 for submerged and DMF 45 for solid-state were isolated by multi-step screening technique based on coefficient of pectolysis and capability of pectinase production. Process variables such as size of inoculum, pH, temperature, particle size and moisture content were optimized with an aim to achieve the maximum production of pectinases. The increased level of pectinase production was recorded at pH 5.0 and temperature 34 degrees C in submerged and solid-state conditions. The optimum inoculum size was 1x10(5)ml(-1) for submerged and 1x10(7)g(-1) for solid-state conditions. Five hundred micrometer particle size and 65% moisture content of the substrate were optimum for the maximum production of pectinases in solid-state condition. Under optimum conditions, maximum production of exo-pectinase was 34.2U/g in SSF and endo-pectinase was 12.6U/ml in SmF.

Production of pectinase from deseeded sunflower head by Aspergillus niger in submerged and solid-state conditions.

Studies were carried out on the production of pectinases using deseeded sunflower head by Aspergillus niger DMF 27 and DMF 45 in submerged fermentation (SmF) and solid-state fermentation (SSF). Higher titres of endo- and exo-pectinases were observed when medium was supplemented with carbon (4% glucose for SmF and 6% sucrose for SSF) and nitrogen (ammonium sulphate, 0.3% for both SmF and SSF) sources. Green gram husk proved to be relatively a better supplement to attain higher yield of endo-pectinase (11.7 U/g) and exo-pectinase (30.0 U/g) in solid-state conditions. Maximum production of endo-pectinase (19.8 U/g) and exo-pectinase (45.9 U/g) by DMF 45 were recorded in SSF when compared to endo-pectinase (18.9 U/ml) and exo-pectinase (30.3 U/ml) by DMF 27 in SmF under optimum process conditions.