Optimization of Cultural Conditions for the Biosynthesis of Phenylalanine ammonia lyase (PAL) by Bacillus subtilis GCB-31 on agro-industrial wastes

摘要

Phenylalanine ammonia lyase (PAL) is the key enzyme that catalyzes the conversion of L-Phenylalanine to ammonia and trans- cinnamic acid. In phenyl propanoid pathway, PAL is the first enzyme which involved in the biosynthesis of polyphenol compounds such as flavonoids and lignin in plants. The present study was conducted with the main objective to optimize the phenylalanine ammonia lyase (PAL) production process by Bacillus subtilis GCB-31 on agro-industrial wastes as carrier substrates in solid state fermentation. The maximum PAL activity was obtained at 30 SUPo/SUPC after 96 h using 1 mL inoculum level. 10g of mixed substrates (Corn Stover+ Corn Cobs+ Banana stalk) was optimized for maximum L-asparaginase production. Agro-industrial wastes, nitrogen sources and carbon sources were also optimized for the maximum production of enzyme (58.77±2.94 U/mL). It was also found that glucose and ammonium sulphate as the best additional carbon and nitrogen sources respectively. It can be inferred from this study that optimization of fermentation process enhanced the production of desired enzyme.