福鼎海域坛紫菜叶状体体表外生细菌的组成和数量分析

从采集自福鼎敏灶湾和硖门湾海域的健康坛紫菜（Porphyra haitanensis）叶状体体表分离、纯化到26株外生细菌．根据细菌菌落特征、菌体形态和16SrDNA基因序列分析相结合的方法进行鉴定，将其确认为6种不同的菌属，分别是假交替单胞菌属（Pseudoaheromonas）、Aquimarinas属、交替单胞菌属（Aheromonas）、黄杆菌属（Flavobacteriums）、弧菌属（Vibrio）和嗜琼胶菌属（Agarivorans）．2个海湾坛紫菜叶状体体表外生菌群数量稳定且差别不大，外生细菌菌属组成基本相同，个别菌属稍有差异，优势菌属为假交替单胞菌属和Aquimarinas属，常见菌属为交替单胞菌属和黄杆菌属，少见菌属为弧菌属．敏灶湾坛紫菜体表外生菌群数量为（5．7～6．5）×10^4cfu／g，外生细菌中各菌属所占比例为：假交替单胞菌属占38．5％，Aquimarinas属占52．8％，交替单胞菌属占13．9％，黄杆菌属占11．5％，弧菌属占3．3％．硖门湾坛紫菜体表外生菌群数量为（6．4～7．6）×10^4cfu／g，外生细菌中各菌属所占比例为：假交替单胞菌属占37．3％，Aquimarinas属占32．0％，交替单胞菌属占14．0％，黄杆菌属占12．7％，弧菌属占2．7％，嗜琼胶菌属占1．3％．优势和常见菌属菌株对健康坛紫菜叶状体进行感染，发现这些菌株对坛紫菜叶状体无致病力，叶状体生长无异常．这些可为坛紫菜微生物学研究提供基础资料．

Analysis of composition and quantities of epiphytic bacteria on the surface of Porphyra haitanensis thallus from Fuding sea

Twenty six epiphytic bacteria were isolated from the healthy thallus of Porphyra haitanensis, which were collected from Fuding Minzao Bay and Fuding Xiamen Bay. Six different bacteria genera were identified as Pseud- oalteromonas ,Aquimarinas ,Alteromonas , Flavobacteriums , Vibrio and Agarivorans by colony characteristics, mycelial morphology and 16SrDNA sequence analysis. The quantity of epiphytic bacteria on the thallus surface of porphyra haitanensis in the two bays was similar showed no significant difference. The composition of bacteria flora on the thallus surface of porphyra haitanensis were basically the same with dominant bacteria Pseudoalteromonas and Aquimarinas, common bacteria Alteromonas and Flavobacteriums, and rare bacteria Vibrio. The quantity of epiphytic bacteria on the thallus surface of Porphyra from Minzao Bay was from 5.7 × 10^4 cfu/g to 6.5 × 10^4 cfu/g. Each bacterial flora shared different proportion in epiphytic bacteria, i. e. Pseudoalteromonas （38. 5% ）, Aquirnarinas （32.8%） ,Alteromonas （ 13.9% ） ,Flavobacteriums （ 11.5% ） and Vibrio （3.3%）. The quantity of epiphytic bacteria on the thallus surface of Porphyra from Xiamen Bay was from 6.4 × 10^4 cfu/g to 7.6 × 10^4 cfu/g. Each bacterial flora shared different proportion in epiphytic bacteria, i. e. Pseudoalteromonas （37. 3% ）, Aquimarinas （32.0%） ,Alteromonas （ 14.0% ） ,Flavobacteriums （ 12.7% ）, Vibrio （2.7%） and Agarivorans （ 1.3% ）. The result from infection experiment showed that dominant and common strains of bacteria had no pathogenicity on the thallus of healthy Porphyra and they grew normally. This paper would provide basic data for further Porphyra microbiological studies.