Selected Essential Amino Acid Enhancement by Bacillus cereus from Solid State Fermentation of Soy Pulp

Abstract

This research was evaluated the enhancement of essential amino acid (EAA) namely isoleucine, valine, methionine, lysine and tryptophan from soy pulp by using solid state fermentation. The EAAs were selected based on their importance and functions in fish nutrition. In this study, eight bacteria were isolated from solid state fermented soy pulp and screened for isoleucine, valine, methionine, lysine and tryptophan enhancement activities. The potential bacteria strain (S1, S2, S3, S4, S5, S6, S7, and S8) were inoculated into solid state medium (soy pulp, 95.5%; yeast extract, 2%; ammonium sulphate, 2%; 0.5% glucose v/v) and subjected to solid state fermentation for eight days. The finding of screening test of bacteria S1 assay performed the highest total EAA bacteria (42.9 ± 19.50 gL-1). This was followed by S3 (28.2 ± 5.21 gL-1), S7 (23.2 ± 5.29 gL-1), S5 (18.8 ± 1.70 gL-1), S4 (30.0 ± 14.0 gL-1), S8 (19.9 ± 2.38 gL-1), S2 (20.3 ± 4.31 gL-1) and S6 (13.9 ± 0.46 gL-1). Bacteria strain S1 was then identified as Bacillus cereus (MH027625) by Polymerase Chain Reaction (PCR) assay and sequencing. Therefore, the present bacteria isolate B. cereus (MH027625) can be used in enhancing EAA for aquaculture use.