Mixture of residual fish hydrolysate and fish extract hydrolysate to activate Bacillus licheniformis 6346

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 -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-1 on days 5 and 6, respectively. Supplementation of residual fish hydrolysate-starch with 3 gL-1 (NH4)2HPO4 increased the -amylase production to 1426 U g DBM-1on the 4th day. Supplementation of residual fish hydrolysate-starch-(NH4)2HPO4 with yeast extract reduced the -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 -amylase production by B. 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.