Applied development of crude enzyme from Bacillus cereus in prebiotics and microbial community changes in soil.

The chitosanase and chitinase activity were revealed in the culture supernatant of Bacillus cereus TKU027 with shrimp head powder (SHP) as the sole carbon/nitrogen source. The chitosan with 60% degree of deacetylation (DD) was depolymerized by TKU027 crude enzyme. The low DP oligomers stimulated the growth of Lactobacillus paracasei BCRC12193 and Lactobacillus kefir BCRC14011 in a MRS broth supplemented with low DP oligomers for 12 h. Conversely, the high DP oligomers (0.1%) had potent inhibitory effects against L. paracasei BCRC12193 and L. kefir BCRC14011 for 48 h. Besides, the study also investigated the effects of B. cereus TKU027 on degradation of SHP and the survival conditions of bacteria in mangrove river sediment of Tamsui River. The 5 weeks-incubation sample of SHP and B. cereus TKU027-amended mangrove river sediment showed the highest amounts of biomass, reducing sugar and total sugar, and some variance of bacterial community compositions existed in the soils.