Succession of sponge-associated bacterial community during the cultivation with hexabromobenzene

Abstract

Sponges (phylum Porifera) produce variety of natural chemicals. According to the recent reports halogenation in the structure of such natural products seemed to be very important for the activity. Many natural chemicals from sponges produced by microorganisms inhabited in its cavity and hence, symbiotic bacteria possibly concerned in halogenation. In the present study, we tried to reveal the effect of hexabromobenzene (HBB) on the community structure of sponge-associated bacteria. Each 1 ml of body fluid from sponge cavity was inoculated into 20 ml of anaerobically prepared marine broth 2216 with or without of final 60 ppm HBB. One ml of cultivate from each microcosm was transferred to fresh medium for 5 weeks with one week interval and bacterial clones were prepared and analyzed from each sample. Bacterial community with HBB was not greatly changed during the cultivation period but fluctuation was greater than that without HBB. Phylotypes displaying high similarity with delta proteobacterium BBD 11-2, Eubacterium oxidoreducens, Fusibacter paucivorans and Cytophaga-like organisms were common in both cultures. Eubacterium and Fusibacter did not consisted till to 5 weeks in both conditions implied that these groups disappeared not by HBB. Clones affiliated into Planctomycetales appeared after 3 weeks with HBB might be a possible candidate of dehalogenation process in sponge cavity. [Supported by MEGRC & KORDI in house Program (PE98210)].