本文采用倾注平板法从湛江硇洲岛全缘马尾藻（Sargassum integerrimum）分离共附生细菌，分别以大肠埃希菌（Escherichia coli）、金黄色葡萄球菌（Staphylococcus aureus）和白色念珠菌（Candida albicans）作为指示菌，利用牛津杯法测定抗菌活性，并对分离到的抗菌活性菌进行形态观察、生理生化试验及分子生物学水平的鉴定与多样性分析。共分离到36株细菌，经形态观察与生化试验去重，筛选到具有抗菌活性的细菌11株。经过16S rRNA分析发现，11株抗菌活性细菌分属于细菌域的厚壁菌门（Firmicutes）和放线杆菌门（Actinobacteria）的5个科（Bacillaceae, Staphylococcaceae, Micrococcaceae, Microbacteriaceae, Dermabacteraceae）、5个属（Bacillus, Staphylococcu, Kocuria, Microbacterium, Brachybacterium）， 其中7株菌为Firmicutes 门，占活性菌株的63.6 %，并成为优势类群，同时发现4株潜在新种（菌株X21、X24、X31、X34）。研究表明，该岛全缘马尾藻中存在较为丰富的抗菌物质产生菌，并蕴藏着较多的微生物新类群。

Antimicrobial activity bacteria associated with Sargassum integerrimum were isolated by using plate pouring method. Their antimicrobial activities were determined by Oxford cup method in which Escherichia coli, Staphylococcus aurous and Candida albicans were used as representative indicators for gram-negative bacteria, gram-negative bacteria and fungi, respectively. The antimicrobial activity strains were then identified according to morphological characteristics, biochemical properties and the phyogenetical analysis of 16S rRNA sequence. The diversity of antimicrobial activity isolates was also analyzed. Results indicated that 36 symbiotic bacteria were isolated, 11 of which had antimicrobial activity The subsequent analysis showed that all of the isolates belonged to five genera (Bacillus, Staphylococcu, Kocuria, Microbacterium, Brachybacterium) of five families (Bacillaceae, Staphylococcaceae, Micrococcaceae, Microbacteriaceae, Dermabacteraceae) in two phylogenetic groups (Firmicutes, Actinobacteria) and among them Firmicutes was their dominant phylum(7 strains, 63.6 %). In addition, four strains with potential new species (X24, X31, X21 and X34) were found. It is suggested that Sargassum integerrimum from Naozhou Island is abundant in the bacteria with antimicrobial activity and more potential new species could be collected.

2012年地方高校国家级大学生创新创业训练项目（201210566017）；广东海洋大学校自然科学基金团队项目(1012017)