【摘要】 采用菌落菌体形态观察和16SrDNA序列比对的方法,对三疣梭子蟹养殖健康塘和病害塘表层底泥中的异养细菌进行了比较研究。分离得到的255株细菌可分为13个菌落类群,33个菌体亚群。对占异养细菌总数34.5%的两个优势亚群(A-NS-SpR亚群,不产芽孢的球杆状菌;B-SF-SR亚群,产芽孢的短杆状菌)的16SrDNA序列分析结果表明,A-NS-SpR亚群属于变形菌门中的2个纲3个科8个属约12个种,其中Halomonas ventosae和Donghicola eburneus两个种数量最多,占该亚群菌株的59.1%。B-SF-SR亚群属于厚壁菌门芽孢菌纲的3个科4个属约12个种,其中Bacillus decolorationis和Halobacillus trueperi两个种数量最多,占该亚群菌株总数的60.6%。从属的水平上讲,Bacillus和Halomonas是优势属。A-NS-SpR亚群在健康塘中的丰度(菌株数量)明显高于病害塘,但多样性(种属数量)差别较小,其中Rhodobacteraceae科在两个塘中的数量差别最大。与此相反,B-SF-SR亚群在健康塘和病害塘中的丰度相当,但健康塘的多样性明显多于病害塘,B.decolorationis和H.trueperi在病害塘中的优势更明显。更多还原

【Abstract】 Heterotrophic bacterial community,in the surface sediment of Portunus trituberculatus rearing ponds with disease occurring and one without,was investigated by means of the morphology and 16S rDNA sequences. A total of 255 isolates were roughly clustered into 13 colony-based groups and 33 cell-based subgroups. The 16S rDNA sequences were analyzed of the two dominant subgroups A-NS-SpR (non spore- forming sphere-rod in A group) and B-SF-SR (spore-forming short-rod in B group),both of which accounted for 34. 5% of all isolates. Subgroup A-NS-SpR belongs to phylum Proteobacteria,including two classes,three families,eight genara and about twelve species,and the dominant species are Halomonas ventosae and Donghicola eburneus,which totally accounted for 59. 1% of this subgroup. Subgroup B-SF-SR belonges to phylum Firmicutes,including one class (Bacilli),three families,four genara and about twelve species. And two species (Bacillus decolorationis and Halobacillus trueperi) accounted for 60. 6% in this subgroup,much more than other species. At genus level,Bacillus and Halomonas are majors within sbugroup. Subgroup A- NS-SpR show much higher abundance (number of isolates) in the healthy pond than in the diseased one,but similar diversity (number of species) with the latter. And family Rhodobacteraceae shows the biggest drop in the abundance in the diseased pond. In contrast,Subgroup B-SF-SR shows minor differences in abundance in healthy and diseased ones,but its diversity in the diseased pond lost obviously,compared with the healty one.更多还原