ARDRA analysis of diversity of Bdellovibrio-and-like organisms in mariculture environment of Apostichopus japonicus

Abstract:

[Objective] To study the diversity and composition of Bdellovibrio-and-like organisms (BALOs) in mariculture environment of Apostichopus japonicus. [Methods] The aquaculture water of A. japonicus was filtered to obtain the microorganisms. Then the total DNA of microorganisms was extracted. The purpose fragments of 16S rRNA gene of BALOs were amplified using two pairs of primers Per and Bac by PCR, respectively. Different patterns were determined with restriction enzymes Hae Ⅲ and Msp I by amplified ribosomal DNA restriction analysis (ARDRA). Positive clones were verified from 60 monoclonal strains. [Results] Eight and nine differences base sequences were obtained from two pairs of primers, respectively, and which were all belong to Bacteriovorax sp. and affiliated with three different clusters. Clusters Ⅰ and Ⅱ are dominant type which are known clusters; Cluster Ⅲ is a new one; The representative strains of Per1 (KP214541) and Bac44 (KP214551) are the dominant species. [Conclusion] The BALOs presented high diversity in mariculture environment of A. japonicus, including known and unknown, and the BALOs should be further isolated and cultured for the study of disease control in A. japonicus culture.