A total of 25 strains were isolated from the intestinal tract of Mystus macropterus. The inhibitory effects of extracellular enzyme activity to common aquat- ic pathogenic bacteria were screened. A probiotic DQHY -7 s...A total of 25 strains were isolated from the intestinal tract of Mystus macropterus. The inhibitory effects of extracellular enzyme activity to common aquat- ic pathogenic bacteria were screened. A probiotic DQHY -7 strain was isolated, and its safety was detected. DQHY -7 strain was preliminarily identified by mor- phological observation, and physiological and biochemical test. Research results showed that DQHY -7 strain had relatively strong production capacities of amylase, cellulase and protease, and could restrict the growth of Escherichia coli, Aeromonas hydrophila and Pseudomonas fluorescens. Results of acute toxicity test showed that 1. 0 × 108 CFU/mL DQHY -7 bacterial suspension showed no pathogenicity to M. macropterus. According to the colony growth pattern and physiological-bio- chemical characteristics of DQHY -7, the strain was identified to be Bacillus subtilis. Research results showed that DQHY -7 strain could be used as a new candi- date strain for feeding microecologicalagent.展开更多
基金Supported by the Planning Project of Basic Scientific Research Funds of Chongqing(2012-esfc-jbky-00405)
文摘A total of 25 strains were isolated from the intestinal tract of Mystus macropterus. The inhibitory effects of extracellular enzyme activity to common aquat- ic pathogenic bacteria were screened. A probiotic DQHY -7 strain was isolated, and its safety was detected. DQHY -7 strain was preliminarily identified by mor- phological observation, and physiological and biochemical test. Research results showed that DQHY -7 strain had relatively strong production capacities of amylase, cellulase and protease, and could restrict the growth of Escherichia coli, Aeromonas hydrophila and Pseudomonas fluorescens. Results of acute toxicity test showed that 1. 0 × 108 CFU/mL DQHY -7 bacterial suspension showed no pathogenicity to M. macropterus. According to the colony growth pattern and physiological-bio- chemical characteristics of DQHY -7, the strain was identified to be Bacillus subtilis. Research results showed that DQHY -7 strain could be used as a new candi- date strain for feeding microecologicalagent.
