【摘要】 从健康大鳍鳠(Mystus macropterus)肠道菌群分离得到25株细菌,通过对菌株胞外酶活力及对鱼类常见病原菌抑制作用进行筛选,从中筛选出一株益生菌DQHY-7菌株。对DQHY-7菌株安全性进行检测,并结合菌株形态观察、生理生化试验,对DQHY-7菌株进行了初步鉴定。结果显示:DQHY-7菌株具有较强的分泌纤维素酶、淀粉酶和蛋白酶能力,能够抑制大肠杆菌(Escherichia coli)、嗜水气单胞菌(Aeromonas hydrophila)和荧光假单胞菌(Pseudomonas fluorescens)的生长。急性毒性试验表明,浓度为1.0×108CFU/mL的DQHY-7菌悬液对大鳍鳠没有致病性。结合DQHY-7菌株菌落生长形态和生理生化特性,初步鉴定为枯草芽孢杆菌(Bacillus subtilis)。研究结果表明DQHY-7菌株可以作为一个新的饲用微生态制剂候选菌种。更多还原

【Abstract】 25 bacterial strains isolated from intestinal tract of Mystus macropterus were used for testing the ectoenzyme-producing ability and the antagonistic effects against three common pathogenic bacteria. The toxicity of strain DQHY- 7 screened as potential probiotic for M. macropterus was evaluated. DQHY- 7 was identified according to its morphological, physiological and biochemical characteristics. The results indicated that DQHY- 7 had high ectoenzyme- producing ability including amylase,cellulose and protease,and DQHY- 7 could produce chemical inhibitor to Escherichia Coil,Aeromonas hydrophila and Pseudomonas fluorescens. It was non- pathogenic for M. macropterus when the concentration of DQHY- 7 was at 1. 0 × 108CFU / mL. Combined with the physiological and biochemical characteristics,DQHY- 7 could be determinedas Bacillus subtilis preliminarily. This study had revealed that DQHY- 7 would be wsed as a candidate strain of microecological in aquaculture.更多还原