Liu Ying, Shi Wei, An Junying, Zhao Yamei, Ye Riying, Xu Chunhou
Wei Sheng Wu Xue Bao. 2014 May 4;54(5):582-8.
Marine bacteria are a rich source of potentially useful antimicrobial molecules. The purpose of the study is to explore the diversity of bacteria with antimicrobial activity isolated from Siganus fuscescens gastrointestinal tract collected from Naozhou Island (20 degrees 52' N-20 degrees 56' N 110 degrees 33' E-110 degrees 38' E), Leizhou Bay, South China Sea.
We isolated bacteria from the gastrointestinal tract of fish sample using classical culturing technique, and determined antimicrobial activities of the isolates by Oxford cup method. We investigated diversity of antimicrobial isolates using phylogenetic comparative analysis of 16S rRNA gene sequences.
According to the results of morphological observation and part of physiological and biochemical experiments, we isolated 68 strains from fish gastrointestinal tract. Among them, 19 strains with antimicrobial activities were acquired (27.9% of the isolates) and represented 19 different species, belonging to 12 genera (Rothia, Micrococcu, Brachybacterium, Brevibacterium, Psychrobacter, Paracoccus, Cobetia, Citrobacter, Pseudomonas, Bacillus, Lactobacillus and Staphylococcus) of 11 families (Microbacteriaceae, Dermabacteraceae, Brevibacteriaceae, Moraxellaceae, Rhodobacteraceae, Halomonadaceae, Enterobacteriaceae, Pseudomonadaceae, Bacillaceae, Lactobacillaceae and Staphylococcaceae) in three phyla (Actinobacteria, Proteobacteria and Firmicutes). Eight strains (42.1%), 7 strains (36.8%) and 4 strains (21.1%) were belonging to the phylum Firmicutes, Proteobacteria and Actinobacteria, respectively. The phylogenetic distance matrix results suggested that there were obvious genetic divergences between the majority of strains with antimicrobial activity and their phylogenetically most closely related typical strain, due to 16S rRNA gene sequences similarities ranging from 96.2 to 99.9%. In addition, 4 strains (ZJHD2-31, ZJHD5-23, ZJHD2-58 and M26) could represent potential new species, and identification of the novel strain M26 has been published in Antonie van Leeuwenhoek.
There are abundant diversity for bacteria with antimicrobial activity and potentially more new species of microorganism in Siganus fuscescens gastrointestinal tract collected from Naozhou Island.
海洋细菌是潜在有用抗菌分子的丰富来源。本研究的目的是探索从中国南海雷州湾硇洲岛（北纬20°52′ - 20°56′，东经110°33′ - 110°38′）采集的黄斑蓝子鱼胃肠道中分离出的具有抗菌活性的细菌的多样性。
我们使用经典培养技术从鱼样本的胃肠道中分离细菌，并通过牛津杯法测定分离株的抗菌活性。我们使用16S rRNA基因序列的系统发育比较分析来研究抗菌分离株的多样性。
根据形态学观察和部分生理生化实验结果，我们从鱼胃肠道中分离出68株菌株。其中，获得了19株具有抗菌活性的菌株（占分离株的27.9%），代表19个不同的物种，属于11个科（微杆菌科、皮肤杆菌科、短杆菌科、莫拉菌科、红杆菌科、盐单胞菌科、肠杆菌科、假单胞菌科、芽孢杆菌科、乳杆菌科和葡萄球菌科）的12个属（罗氏菌属、微球菌属、短芽孢杆菌属、短杆菌属、嗜冷杆菌属、副球菌属、考贝氏菌属、柠檬酸杆菌属、假单胞菌属、芽孢杆菌属、乳杆菌属和葡萄球菌属），分属于三个门（放线菌门、变形菌门和厚壁菌门）。八个菌株（42.1%）、七个菌株（36.8%）和四个菌株（21.1%）分别属于厚壁菌门、变形菌门和放线菌门。系统发育距离矩阵结果表明，由于16S rRNA基因序列相似性在96.2%至99.9%之间，大多数具有抗菌活性的菌株与其系统发育关系最密切的典型菌株之间存在明显的遗传差异。此外，四个菌株（ZJHD2 - 31、ZJHD5 - 23、ZJHD2 - 58和M26）可能代表潜在的新物种，新菌株M26的鉴定已发表在《安托尼·范·列文虎克》杂志上。
从硇洲岛采集的黄斑蓝子鱼胃肠道中具有抗菌活性的细菌种类丰富，可能存在更多潜在的新微生物物种。
