Vipul Gohel

Statistical optimisation of medium components for chitinase production byPaenibacillus sabina strain JD2

Paenibacillus sabina strain JD2, a chitinolytic marine bacterium, was isolated from sea dumps collected at Sultanpur near Bhavnagar, India and its nutritional requirement for chitinase production was defined using statistical optimisation method. Effect of 8 different medium components on chitinase production byPaenibacillus sabina strain JD2 was screened by Plackett-Burman design. The screened medium components were further used in central composite design where chitinase production, pH and biomass responses were used in different models to evaluate fit ones. After performing power transformation, quadratic model was found to be fit for chitinase response and 2F1 model was found to be fit for biomass response. Whilst for pH response, quadratic model was found to be fit without any requirement of power transformation. In multiresponse analysis, medium formulation consisting of (g/l): chitin 18, yeast extract 0.50, and CaCl2 0.08, was found to predict 82.93 U/ml of chitinase with overall highest desirability of 0.842 as compared to other formulations. The selection of model was done on basis of high adjusted R2 value and loweredp-value for each model in individual analysis of each response. Through desirability analysis, it was found that biomass and pH played an important role in increasing the chitinase production byPaenibacillus sabina strain JD2. Through statistical optimisation method, 2.74-fold increase in chitinase production was achieved as compared to unoptimised medium.

Biological control ofFusarium wilt of pigeonpea byPantoea dispersa, a field assessment

Fusarium wilt is one of the major yield and growth-limiting factors of pigeonpea (Cajanus cajan). For an ecofriendly and sustainable management of such a disease, a novel mycolytic strainPantoea dispersa was evaluated against fungal pathogenFusarium udum that is known to be infecting the susceptible variety of pigeonpea (T-15-15), commonly prevalent in India. To study the efficacy ofP. dispersa as a biocontrol agent in comparison with chemical fungicide Bavistin and antifungal biocontrol agentTrichoderma Monitor WP was studied in both pot and field experiments.In vitro, P. dispersa inhibits the growth ofF. udum. In the pot experiment,P. dispersa the treated pigeon pea (T-15-15) seeds showed higher percentage of seed germination and decreased wilt incidence as compared to chemical fungicide; Bavistin and antifungal biocontrol agentTrichoderma Monitor WP treatments. Moreover, the root, shoot lengths and growth were also found to be higher. Due to high impact ofP. dispersa inin vitro condition on controlling theF. udum growth, further study was conducted in field in a wilt-stricken plot. These studies were repeated for three cropping seasons (2004/2007). The seed dressing byP. dispersa reduced wilt incidence (47%) during field trials, which is greater than Bavistin (41%) andTrichoderma Monitor WP (36%) treatments. HenceP. dispersa was proven superior toTrichoderma Monitor WP and Bavistin; which are used as commercialFusarium wilt control agents.

Industrial Enzyme Applications in Biorefineries for Starchy Materials

This chapter reviews recent advances in technology developments in biorefinery industries through enzymatic approaches where various starchy materials have been used as feedstock for biofuel and various syrup productions. It further discusses the enzymes discovery, industrial challenges, and how enzymatic-based approaches help different industries to develop environmentally sustainable and cost-effective solutions by making industrial process into more simplified without compromising the product and by-product yields and their qualities.