Bioconversion of agricultural by-products to lysine by Brevibacterium flavum and physico-chemical optimization for hyper-production

Poultry and agriculture industry has a great role in the development of food sector in pakistan. whole of the lysine required for poultry feed is imported to fulfil the desired dietary needs. present study was designed to utilize different agricultural by-products like molasses,wheat bran,rice polishing and corn steep liquor. different physico-chemical parameters were optimized to have hyper-production of lysine through fermentation by using brevibacterium flavum as a fermentative agent. from wheat bran,rice polishing and molasses (as best carbon source),significantly high concentrations of lysine (10.4 g/l) after 72h of incubation was observed with molasses (4%) with 3% (v/v) inoculum size at 30o c and ph 7. among different nitrogen sources,0.25% (nh4)2so4 showed significantly (p< 0.05) high yield of lysine (16.89 g/l). addition of different optimum levels of ionic salts; 4% caco3,0.4% mgso4.7h2o,0.1% nacl and 0.2% kh2po4 gave significantly (p< 0.05) higher quantity of lysine 19.01 g/l. inclusion of 0.6% corn steep liquor and 0.4 mg/100ml biotin significantly (p< 0.05) raised the lysine from 19.4 g/l- 19.45 g/l. the presence of lysine in fermented broth was detected by tlc. thus a cheap and practical bioprocess of lysine production was concluded,that can be exploited commercially to save foreign exchange. © 2015,chemical society of pakistan. all rights reserved.