High Level Production of Extracellular α-Amylase from Bacillus licheniformis ATCC 12759 in Submerged Fermentation

Abstract

Alpha amylase (E.C. 3.2.1.1) of Bacillus licheniformis ATCC 12759 was shown to produce extracellular α-amylase in submerged fermentation.Various nutrients belonging to three categories, carbon, nitrogen and amino acid sources, were investigated in terms of their effect on the production of extracellular α-amylase by Bacillus licheniformis ATCC 12759. Amongst carbon sources sugars, arabinose, sucrose, corn flour and corn starch supported maximum amylase production. Casein, sodium nitrate, ammonium sulphate, ammonium chloride, and ammonium nitrate where the best organic sources and inorganic sources respectively. Among the amino acid sources tested, L-cysteine, L-tryptophane, Lvaline, L-phenylalanine, L-methionine and L-lysine were favored the production respectively. FeSO4, ZnSO4 and CuSO4 inhibited α-amylase production. Maximum α-amylase production (1074.8±35.0 U/mg) was obtained in a medium containing 0.01% L-cysteine in 72 h at 37 oC.