Lipase Production from Bacillus subtilis MTCC 6808 by Solid State Fermentation Using Ground Nut Oil Cakes as Substrate

摘要

A comparative study on the production of extra cellular lipase by Solid State Fermentation (SSF) using Bacillus subtilis with various substrates has been made. Different parameters such as temperature, pH, different substrates and effect of incubation time of the medium were optimized for maximum yield. The maximum extracellular lipase activity of 4.5 units per gram of dry fermented substrates (U g dS~-1) was observed with ground nut oil cake after 48 h of fermentation with 70% initial moisture content of the substrate and suitable growth of bacterial mass culture was for maximum yield of lipase at pH 8 was observed.Lipases (triacylglycerol acylhydrolases, EC 3.1.1.3) catalyze the hydrolysis and the synthesis of esters formed from glycerol and long chain fatty acids. In contrast to esterases, lipases are activated only when adsorbed to an oil-water interface (Martinelle et al., 1995). Commercially useful lipases are usually obtained from microorganisms that produce a wide variety of extracellular lipases. Only about 2% of world's microorganisms have been tested as enzyme sources. Microbial Upases are produced mostly by submerged culture (Ito et al., 2001), but solid-state fermentation methods can be also used (Chisti, 1999). In general, solid-state fermentation is a well-adapted and cheaper process than submerged fermentation for the production of a wide spectrum of bioproducts (animal feed, enzymes, organic acids, biopulp, aroma compounds, antibiotics, compost, biopesticide, biofertilizer etc). Solid state fermentation is a high recovery method for the production of industrial enzymes (Pandey et al., 1999).