海洋弧菌多样性

Diversity of Marine Vibrios

海洋弧菌泛指异营性、好盐性、兼性嫌气性革兰氏阴性杆菌中,具有发酵葡萄糖等醣类能力者。它们遍布于内湾、沿岸和大洋水域及海底沉积物,也遍布于形形色色海洋生物体表和体内。这类细菌中,有少数种类是海洋鱼类和无脊椎动物特化发光器官内共生者,另有许多其它种类是人类和海洋动物病原体。海洋弧菌具有各类物质分解能力,包括能降解几丁质、洋菜等复杂多醣类,因而可能在沿岸环境有机物质循环再生中,扮演重要角色。这类细菌的固氮作用,可能是海洋环境中氨态氮重要来源之一。16SrDNA序列之亲源分析显示,海洋弧菌隶属γProteobacteria。七十多种海洋弧菌目前被归类于Enterovibrio、Grimontia、Photobacterium、Salinovibrio和Vibrio五属;前两属属于Enterovibrionaceae ,后三属分别属于Photobacteriaceae、Salinovibrionaceae和Vibri onaceae。利用限制型分析于区分16SrDNA基因型,是一种简易快速,而又有效于遂行海洋弧菌分离株初步分类的方法。

Marine vibrios are heterotrophic, halophilic, facultatively anaerobic, Gram-negative, rod-shaped bacteria capable of fermenting glucose and other carbohydrates. They are ubiquitous in estuarine, coastal and oceanic waters and in marine sediments. They are closely associated with many kinds of marine organisms from plankton to fish. Some species are found as symbionts in certain luminous organs of marine fish and invertebrates, whereas many other species are pathogens of humans or marine animals. Marine vibrios may play an important role in the recycling of organic matter in coastal environments since they can degrade a variety of substances, including complex polysaccharides such as chitin and agar. The fixation of N 2 by these bacteria may be an important input of ammonium nitrogen for marine environments. Phylogenic analysis based on 16S rDNA sequences indicated that marine vibrios belong to (-Proteobacteria. More than seventy species of marine vibrios are currently placed in the genera Enterovibrio, Grimontia, Photobacterium, Salinovibrio and Vibrio; the former two genera belong to Enterovibrionaceae, while the latter three genera belong to Photobacteriaceae, Salinovibrionaceae and Vibrionaceae, respectively. Differenti- ation of 16S rDNA genotypes based on analysis of restriction patterns appears to be a simple, rapid and useful technique for preliminary classification of marine vibrios.