中文摘要：

利用海水琼脂、TCBS和MRS培养基对斜带石斑鱼Epinephelus coioides幼鱼消化道和养殖水体中的细菌进行分离纯化，采用生理生化鉴定结合16SrRNA基因测序进行细菌鉴定，探讨了幼鱼消化道中的菌群与养殖水体中菌群的关系。结果表明：幼鱼消化道中可培养细菌总数（9．0×106cfu／g）高于养殖水体中可培养细菌总数（5．4×105cfu／mL），幼鱼消化道中细菌种类也明显多于养殖水体；在幼鱼消化道和养殖水体中均检测到副溶血弧菌、哈维氏弧菌、短小芽孢杆菌、克劳氏芽孢杆菌、鲍氏不动杆菌、嗜冷杆菌和洋葱伯克霍尔德菌等7种细菌。细菌系统进化分析结果表明，这些细菌隶属于β-变形杆菌纲、γ-变形杆菌纲和芽孢杆菌纲。幼鱼消化道和养殖水体的优势菌中均有芽孢杆菌和嗜冷杆菌，提示芽孢杆菌和嗜冷杆菌能通过养殖水体很好地进入消化道。3种乳酸菌（乳酸乳球菌、干酪乳杆菌和屎肠球菌）仅见于幼鱼消化道，且仅占消化道菌群数量的0．70％。弧菌在消化道和养殖水体中所占比例均很小，分别仅占细菌总数的1．07％和0．10％。

英文摘要：

The microbiota in the gut of juvenile grouper Epinephelus coioides and aquaculture water were isolated and purified by marine agar, TCBS and MRS media. The traits of the cultivable bacteria were analysed by physiological and biochemical tests in combination with 16S rRNA gene sequence analysis. The results showed that there were higher total cultivable bacterial number（9.0 × 106 cfu/g）and species in gut of the grouper than those in the aquaculture water（5.4 ×105 cfu/mL）. Seven bacterial species, however, were found in both the gut and aquaculture water, i.e. Vibrio parahaemolyticus, Vibrio harveyi, Bacillus pumilus, Bacillus clausii, Acinetobacter baumannii,Psychroacter sp. and Burkholderia cepacia, which were classified into 3 groups γ- proteobacteria, β - pro- teobacteria and Bacilli. Bacillus and Psychrobacter invading into the gut via the aquaculture water were found to be the predominant bacteria in the gut and aquaculture water. Three species of lactic acid bacteria, Lactococcus lactis, Lactobacillus casei and Enterococcusfaecium were isolated only from the gut, but comprising only 0.70% of the total bacteria. Furthermore, the amount of Vibrio in the gut and aquaculture water was very low, accounting for only 1.07% and 0.10% of the total bacteria, respectively.