Abstract

 Microbes are first activated in appropriate media before cultivation/fermentation.Bacillus licheniformis 6346 activated in nutrient broth-starch was inoculated to a locally formulated solid medium (paddy husk, rice flour, (NH₄)₂SO₄, cuttle fish powder, murate potash, table salt, triple super phosphate, sesame oil, coconut oil and tap water) and the highest α-amylase activity was obtained on day 5 (1075 U g DBM^-1) at 42°C. Replacement of nutrient broth-starch with residual fish hydrolysate-starch led to the enzyme production to 1100.3 and 1180.4 U g DBM^-1on days 5 and 6, respectively. Supplementation of residual fish hydrolysate-starch with 3 gL^-1 (NH₄)₂HPO₄ increased the α-amylase production to 1426 U g DBM^-1on the 4th day. Supplementation of residual fish hydrolysate-starch-(NH₄)₂HPO₄ with yeast extract reduced the α-amylase production to 877 U g DBM^-1. Mixing residual fish hydrolysate with fish extract hydrolysate in the volume ratio of 1: 32.6 and supplementing starch and (NH₄)₂HPO₄ increased the enzyme production to 2328 U g DBM^-1. Maintenance of amino acid content in terms of glycine or tyrosine in activation medium did not show significant correlation with α-amylase production byB. licheniformis. This study shows that, to activate B. Licheniformis, residual fish hydrolysate - starch - (NH₄)₂HPO₄ - fish extract hydrolysate could be used instead of nutrient broth-starch.

Key words: ï¡ï€­Amylase, Bacillus licheniformis, fish extract hydrolysate, paddy husk, solid state fermentation.