军曹鱼肠道细菌及其产酶能力的研究

Study on intestine bacteria from Rachycentron canadum Linnaeus and its zymogenicities

对军曹鱼Rachycentron canadum Linnaeus肠道异养细菌进行一周年的监测，分离得到的94株优势菌（2004年4月～2005年3月）鉴定到属，并检测产生蛋白酶、淀粉酶和脂肪酶的能力。结果显示，鱼肠道异养菌和弧菌数分别为16．7～8．7×10^8cfu／g和5．0～6．0×10^8cfu／g。肠道异养菌及弧菌的数量高峰均出现于6～7月份，并于12月份和次年2月份出现次高峰。94株优势菌分属假单胞菌属Pseudomonas、芽孢杆菌属Bacillus、气单胞菌属Aeromonas、肠杆菌科的部分属Enterbacteriaceae、弧菌属Vibrio等。产酶试验结果表明，能分泌蛋白酶的菌株占16．0％，18．1％分泌淀粉酶，37．2％分泌脂肪酶，其中8株能同时分泌这3种酶。产酶菌株总比例高达43．6％，可见军曹鱼的肠道细菌在其消化过程发挥重要作用。

The quantitative and qualitative studies of the bacterial flora of farmed cobia （Rachycentron canadum Linnaeus） were performed for one year. Their zymogenicities of protease, amylase and lipase were measured. The results showed that the heterotrophic bacteria and vibrio ranged from 16.7 to 8.7×10^8cfu/g and 5.0 to 6.0×10^8cfu/g in intestine of the cobia, respectively. The crest value for heterotrophic bacteria and vibrio appeared in Jul.. The 94 strains were identified as Pseudomonas sp. , Bacillus sp. , Aeromonas sp, Enterbacteriaceae and Vibrio sp. and so on. Zymogenic experiment results showed that 16.0% of strains produced extracellular protease, 18.1% produced amylase and 37.2% produced lipase. 8 strains were able to produce three enzymes. All the zymogenic bacteia was 43.6%. Therefore, it is clear that bacteria in intestine of cobia play an important role in the digestion of food.