Changes in Bacterial Community Structure during Shrimp Production in a Biofloc-based Aquaculture System

초록

Shrimp (Litopenaeus vannamei) aquaculture is one of the most important aquaculture industries in Asia. The Biofloc technology that is based upon zero or minimal water exchange has been recently employed in L. vannamei aquaculture and led to dramatic increase in shrimp production. Bioflocs consist of a variety of bacteria, fungi, microalgae, and other suspended organisms and play a key role in the growth of shrimp via removal of toxic nitrogen species and serving as nutritional feed. However, bacterial community structure of biofloc-based aquaculture system and variation of the community during shrimp rearing have been rarely identified. In this study, we investigated the bacterial community structure of rearing water and bioflocs in the shrimp aquaculture using 16S rRNA gene amplicon sequencing. The 16S rRNA gene sequence analysis revealed that members of the Rhodobacteriales, Flavobacteriales, and Chitinophagales were dominant in the bioflocs, while members of the Flavobacteriales, Chitinophagales, and Balneolales were predominantly present in the rearing water throughput the entire aquaculture period. Albeit present in minor, bacterial groups of ammonia oxidizing bacteria and nitrite oxidizing bacteria were detected and their relative abundances in the bioflocs were 200 times higher than those in the rearing water. [This study was supported by a grant from the Collaborative Genome Program of the KIMST funded by the MOF (No. 20180430), Republic of Korea]