Department of Marine Bioscience, Fukui Prefectural University, Gakuen-cho, Obama, Fukui 917-0003, Japan.
Microbes Environ. 2012;27(2):193-9. doi: 10.1264/jsme2.me11278.
Fish farm sediments receive a large amount of organic matter from uneaten food and fecal material. This nutrient enrichment, or organic pollution, causes the accumulation of sulphide in the sediment from the action of sulphate-reducing bacteria (SRB). We investigated the effect of organic enrichment around coastal fish farms comparing the SRB community structure in these sediments. Sediment samples with different levels of organic pollution classified based upon the contents of acid-volatile sulphide and chemical oxygen demand were collected at three stations on the coast of western Japan. The SRB community composition was assessed using PCR amplification, cloning, sequencing and phylogenetic analysis of the dissimilatory sulphite reductase b-subunit gene (dsrB) fragments using directly extracted sediment DNA. Sequencing of the cloned PCR products of dsrB showed the existence of different SRB groups in the sediments. The majority of dsrB sequences were associated with the families Desulfobacteraceae and Desulfobulbaceae. Clones related to the phylum Firmicutes were also detected from all sediment samples. Statistical comparison of sequences revealed that community compositions of SRB from polluted sediments significantly differed from those of moderately polluted sediments and unpolluted sediments (LIBSHUFF, p<0.05), showing a different distribution of SRB in the fish farm sediments. There is evidence showing that the organic enrichment of sediments influences the composition of SRB communities in sediments at marine fish farms.
养殖场底泥会接收大量未被食用的食物和粪便中的有机物。这种营养物质的富集，或者说有机物污染，导致了硫酸盐还原菌（SRB）作用下底泥中硫化物的积累。我们研究了沿海养殖场周围有机物富集对底泥中 SRB 群落结构的影响。在日本西部沿海的三个站位采集了不同有机污染水平的底泥样本，这些样本是基于酸可挥发性硫化物和化学需氧量的含量来分类的。使用直接从底泥中提取的 DNA，通过聚合酶链式反应（PCR）扩增、克隆、测序和对异化亚硫酸盐还原酶 b 亚基基因（dsrB）片段的系统发育分析，评估了 SRB 群落组成。dsrB 的克隆 PCR 产物测序显示，底泥中存在不同的 SRB 群体。dsrB 序列的大多数与脱硫杆菌科和脱硫球形菌科有关。所有底泥样本中也检测到与厚壁菌门相关的克隆。序列的统计学比较表明，受污染底泥中的 SRB 群落组成与中度污染底泥和未污染底泥有显著差异（LIBSHUFF，p<0.05），表明养殖场底泥中 SRB 的分布不同。有证据表明，底泥中的有机物富集会影响海洋养殖场底泥中 SRB 群落的组成。
