The Effect Of Bacillus Probiotics On Microbial Communities And Shrimp Intestinal Microflora

Degrading the organic matter fast, Bacillus became a probiotics to regulate water quality in aquaculture. The studies of Bacillus focusing on suppressing pathogenic bacteria, improving enzyme activation under laboratory condition, reducing ammonia nitrogen and chemical oxygen consumption, and improving survival rate of shrimps and fish had been reported, but few studies about microbial communities affected by Bacillus. The purpose of this study was to investigate the effect of Bacillus probiotics on microbial communities of shrimp ponds, with the aim to discuss the mechanism at community level.The present research divided into three sections. First, variation of bacterial communities in the sediment after being treated by a Bacillus commercial probiotics during the shrimp cultivation period was studied with traditional methods to test bacteria. Second, the effect of a Bacillus probiotics feed additive on composition and carbon utilization of shrimp intestinal microflora was investigated by BIOLOG Third, the effect of a Bacillus probiotics on the microbial community composition and carbon utilization of microflora in water, sediment and shrimp intestine was investigated by BIOLOG and traditional method at the late farming stage, comparing with the pond that did not use any probiotics.The results showed that Bacillus changed bacterial species composition of sediment and increased the number of aerobic bacteria.The number of Flavobacterium and Cytophaga increased, while the number of Vibrio and Photobacterium reduced. Bacillus probiotics became the dominant species of the intestinal aerobic bacteria community, kept the intestinal microflora steady and increased the utilization of carbon sources. Bacillus probiotics affected the biomass and genus composition of microbial communities in the water, sediment, and shrimp intestine, improving the utilization of carbon sources, especially the polymer carbon by microorganisms.