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This project was planned to study the production of cholesterol lowering drug mevastatin by Aspergillus terreus GCBL-03 on pretreated substrate bagasse in solid state fermentation. Bagasse was pretreated by potassium hydroxide to delignify the substrate to readily become available to microorganism. It was noticed that pretreated bagasse exhibited 13.69±0.64 mg/100mL yield of mevastatin and 6.63±0.48 g dry cell mass as compared to nontreated substrate that showed 7.04±0.81 mg/100 mL and 6.04±0.24 g dry cell mass. The fermentation profile like pH (5.5), temperature (30 °C), moisture contents (60%) inoculum size (2 mL), and incubation time (72 h) showed the optimum production (30.63±1.24 mg/100 mL) of mevastatin. Furthermore, fermented drug showed noteworthy antifungal activity against battery of selected fungal strains assessed by disc diffusion and measurement of minimum inhibitory concentration by micro dilution method. It was concluded from the study that fermented mevastatin was effective against fungal strains.

The main purpose of this research was to optimize the production of urate oxidase through mutagenesis of Bacillus subtilis. The organism was subjected to ultra violet irradiation and chemical mutagenesis. The strain was chemically mutated by using ethyl methane sulfonate and ethidium bromide. 2- thiouric acid was used as a selective marker to identify the UV and chemically mutated Bacillus subtilis. Ethyl methane sulfonate treated B. subtilis (180 minutes dose) was proved to be the best for optimum production of urate oxidase by 3 log kill/survival curve. Fermentation medium was also optimized, it was found that substrate concentration (0.5%), fermentation period (36 h), pH (8.5), temperature (35°C), inoculum size (3%) enhanced the activity (42.77 ± 0.36 U/mL) of mutant derived enzyme. [ABSTRACT FROM AUTHOR]

Aspergillus niger was subjected to UV radiation and chemical mutagenesis to develop its hyper-producing mutants for enhanced citric acid production. Ethyl methane sulfonate (EMS) and Ethidium bromide (EB) were used for chemical mutagenesis of Aspergillus niger. UV, and chemically treated mutants of Aspergillus niger were identified by using 2-deoxy, D-glucose as selective marker. The selected mutants were cultured in solid state fermentation (SSF) of sugarcane molasses medium (10%) using corn cobs, banana stalk, sugarcane bagasse, wheat straw, and wheat bran as carrier substrates. After pH adjustment and sterilization, the triplicate flasks were inoculated with 5 mLof homogenous spore suspensions of selected mutants of A. niger and the flasks were subjected to SSF under still culture conditions. The mutant EB-3 (treated with 1 mg/mL ethidium bromide for 120 min) giving highest citric acid yield (64.2 mg/mL) in 72 h was selected as hyper-producing mutant. Citric acid production process using EB-3 mutant was then optimized to enhance citric acid production by the mutant in SSF. Aspergillus niger EB-3 mutant could produce 67.72 mg/mL citric acid in 72 h using banana stalks as support material under optimum conditions of pH (pH 6), incubation temperature (35°C) and inoculum size (5 mL) in SSF. [ABSTRACT FROM AUTHOR]

The aim of this project was to improve the Aspergillus terreus strain and pretreatment of sugarcane bagasse as carrier substrate for bulk production of lovastatin, a cholesterol-lowering drug, in solid state fermentation. Sugarcane bagasse was treated with alkali (1–3% NaOH) for the conversion of complex polysaccharides into simple sugars for better utilization of carrier substrate by microorganism for maximum lovastatin production. Ethidium bromide (time of exposure 30–180 min) was used to induce mutation in Aspergillus terreus and the best mutant was selected on the basis of inhibition zone appeared on petri plates. Fermented lovastatin was quantified by high-performance liquid chromatography. The fermented lovastatin, produced by parent and mutant Aspergillus terreus strain, was checked on body weight, blood glucose and serum cholesterol, ALT, AST, HDL-C, LDL-C, TG and TC levels of rats for their cholesterol lowering capacity. Our results indicate that selected strain along with 2% NaOH treated sugar cane bagasse was best suitable for bulk production of lovastatin by fermentation and fermented lovastatin effectively lower the cholesterol level of rats. [ABSTRACT FROM AUTHOR]