Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou, China.
J Appl Microbiol. 2012 Dec;113(6):1341-51. doi: 10.1111/jam.12008. Epub 2012 Oct 1.
To identify the intestinal microbial diversity in mud crab and to investigate the bacterial difference in the intestinal microbiology between wild crabs (WC), pond-raised healthy and diseased crabs (DC).
The intestinal microbial community of mud crab Scylla paramamosain from WC, pond-raised healthy crabs (HC) and DC were examined by Denaturing Gradient Gel Electrophoresis (DGGE) and clone library analysis of 16S rDNA gene. Eight of 21 representative DGGE bands were affiliated with unidentified or unclassified bacteria. Vibrio, Pseudoalteromonas and Shewanella were also found from the DGGE gel. Analysis of clone libraries revealed that all sequenced clones were grouped into either of the following phyla: Proteobacteria, Firmicutes, Tenericutes, Bacteroidetes, Fusobacteria, Cyanobacteria and unidentified or unclassified bacteria. The phylotypes affiliated with Firmicutes were not found in DC library, yet DC had a little portion of Cyanobacteria which did not exist in both WC and HC library. Real-time PCR showed that the abundance of the total bacterial load in WC were significantly three times higher than that in healthy and DC, the abundance of Bacteriodes in healthy and WC were as much four times, three times as that in DC, respectively.
Statistical analysis showed that the bacterial communities in intestine of the mud crab from these three populations were significantly different. The phylotypes of the Bacteriodes and Tenericutes were the dominant population in the gut of the mud crab.
This study demonstrated significant differences in the intestinal bacterial composition of three crab populations. This knowledge will increase our understanding of the effect of growth conditions on bacterial community composition in the crab gut and provide necessary data for further development of probiotic products for diseases prevention in crab farming.
鉴定泥蟹的肠道微生物多样性，并研究野生蟹（WC）、池塘养殖健康蟹（HC）和患病蟹（DC）肠道微生物学的细菌差异。
通过变性梯度凝胶电泳（DGGE）和 16S rDNA 基因克隆文库分析，检测来自 WC、池塘养殖健康蟹和患病蟹的泥蟹 Scylla paramamosain 的肠道微生物群落。21 条代表性 DGGE 条带中的 8 条与未鉴定或未分类的细菌有关。DGGE 凝胶中还发现了弧菌、假交替单胞菌和希瓦氏菌。克隆文库分析显示，所有测序克隆均分为以下门：变形菌门、厚壁菌门、无壁菌门、拟杆菌门、梭杆菌门、蓝细菌和未鉴定或未分类的细菌。未在 DC 文库中发现与厚壁菌门相关的表型，而 DC 中有一小部分蓝细菌不存在于 WC 和 HC 文库中。实时 PCR 显示，WC 中总细菌负荷的丰度明显比健康和 DC 高 3 倍，健康和 WC 中的拟杆菌丰度分别是 DC 的 4 倍和 3 倍。
统计分析表明，这三个群体的泥蟹肠道细菌群落存在显著差异。拟杆菌和无壁菌的表型是泥蟹肠道中的主要种群。
本研究表明，三种蟹类肠道细菌组成存在显著差异。这一知识将增加我们对生长条件对蟹肠道细菌群落组成影响的理解，并为进一步开发用于蟹类养殖疾病预防的益生菌产品提供必要的数据。
