Search

The effects of an exogenous probiotic (Bacillus amyloliquefaciens) on microbial community structure of Branchionus plicatilsand Artemia sinicawere evaluated in this study during turbot (Scophthalmus maximus) larval breeding. The analysis and comparison of the microfloral composition of live feed with probiotic was conducted using the Illumina HiSeq PE250. The abundance of microbial species and diversity of microflora in live feed with B. amyloliquefacienswere higher than those in the control. The microfloral composition was similar among the three replicate experimental groups of B. plicatilscompared with the control after enrichment. Lactococcus, Pseudoalteromonas, and Alteromonaswere always dominant. Additionally, some other bacterial species became dominant during the enrichment process. The microbial community during nutrient enrichment of A. sinicawas rather similar among the three control replicates. Relative abundance of Cobetiasp., the most dominant species, was 54%–65.2%. Similarity in the microbial community was still high after adding B. amyloliquefaciens. Furthermore, Pseudoalteromonasand Alteromonasreplaced Cobetiaas the dominant species, and the abundance of Cobetiadecreased to 4.3%–25.3%. Mean common ratios at the operational taxonomic unit level were 50%–60% between the two B. plicatilsand A. sinicatreatments. Therefore, the microbial community structure changed after adding B. amyloliquefaciensduring nutrient enrichment of B. plicatilsor A. sinicaand tended to stabilize. Additionally, the abundance of Vibrioin any kind of live feed was not significantly different from that in the control. These results will help improve the microflora of B. plicatilsand A. sinicaand can be used to understand the multiple-level transfer role of probiotic species among probiotic products, microflora of live feed, and fish larvae.