Abstract:

Isolation of intestinal bacteria from zebrafish (Danio rerio) and their physiological and biochemical characteristics LV Aijun1, YANG Zhengxing1, LIU huan1, HU Xiu-cai2, ZHANG Yanhua1, CHENG Chao1 (1 School of Life Sciences, Xuzhou Normal University, XuzhouJiangsu,221116 2 Key Laboratory of Biotechnology for Medicinal Plants, Xuzhou Normal University, Xuzhou Jiangsu 221116) Abstract: The bacteria were isolated from the intestine of zebrafish (Danio rerio), the four isolated strains were named ZF-1～4, respectively. Microscopic examination and bacterial culture results showed that all bacterial isolates were Gram-positive spherical (coccus) or rod-shaped (bacillus) bacteria. The isolates ZF-1 and ZF-2 were formed with the small, round, moist, neat colonies on ordinary nutrient agar plates, while the isolates ZF-3 and ZF-4 were showed with the big, dry, wrinkled surface and irregular colonies. The results of physiological and biochemical test revealed that four isolates were fermentation and nonmotile bacteria, the gluconate, citrate, sorbitol, hydrogen sulfide and indole test were negative, but β-galactosidase, phenylalanine deaminase, nitrogen monoxide and glycosides hydrolysis were positive. Isolated strain ZF-1 could use glucose to produce acid and gas and ferments sugars including raffinose and xylose, while ZF-2 and ZF-4 strains could not use. Isolated strain ZF-3 was positive for adonitol fermentation and negative for nitrate reduction or gelatin liquefaction, while other isolates were reversed. The above results provide a reference for the further identification of intestinal bacteria from zebrafish.