Optimization of low-cost solid-state fermentation media for the production of thermostable lipases using agro-industrial residues as substrate in culture of Bacillus amyloliquefaciens

Herein, we describe an optimized protocol of low-cost solid-state fermentation media for the production of thermostable lipases in culture of Bacillus amyloliquefaciens. The bacteria isolated from environmental samples was tested for lipase production. Lipase production media was optimized with cheap agro-industrial wastes and investigated for enhanced production of lipases by the identified strain in solid-state fermentation. The obtained en-zymes were subjected to different physiochemical parameters for their stability checking. Morphological, biochemical and genetic studies shows that the bacterium is gram positive, rod shape Bacillus amyloliquefaciens. Lipase production was observed as 36 U/mL and 35.97 U/mL in media contain-ing 1% fructose and 1% sucrose respectively. The best nitrogen sourced was determined as yeast extract (40 U/mL), peptone (39.90 U/mL), NH4NO3 (30.43 U/mL) at I mM Mg+2, Mn+2, Ca+2 and K+. The inoculum size was optimized as 3-5 % at an incubation time of 72 hrs that yield 80.63 U/mL lipases at an incubation temperature 40 & DEG;C and media pH as 7.0. The best results were obtained with agro-industrial waste with optimum enzyme production as 41.20 U/mL in soya bean extract, 25.87 U/ml in rice bran, 25.83 U/mL in wheat bran, 30.03 U/mL (sunflower) and 32.23 U/mL in oat bran. It is concluded that agriculture wastes are the cheapest sources of substrates for the production of low cost lipase enzyme with commercial ap-plications.

Automated summary

In this study, a low-cost solid-state fermentation media was optimized for the production of thermostable lipases in Bacillus amyloliquefaciens culture. Cheap agro-industrial wastes were used to enhance lipase production. The obtained results showed that agro-industrial wastes are the cheapest sources for low-cost lipase production.