1株乳酸菌在凡纳滨对虾养殖中的应用效果

Application of Lactic Acid Bacteria in Shrimp Farming

利用从对虾消化道分离出的1株乳酸菌优势菌株HN3,分别对哈维氏弧菌和副溶血弧菌进行体外拮抗实验,同时通过乳酸菌拌料投喂的方式开展凡纳滨对虾的养殖试验。结果表明：乳酸菌液及中和酸性后的胞外液均对2种弧菌有显著的抑制效果（P〈0.05）;乳酸菌拌料投喂能显著提高对虾的养殖存活率、日增体质量和特定增长率（P〈0.05）;对虾消化道和养殖水体中的乳酸菌和总细菌数量大幅增加,弧菌数量显著降低（P〈0.05）,其中,以乳酸菌添加剂量4×106 5×106cfu·g-1的综合养殖效果最佳。此株乳酸菌适应对虾消化道的环境并能定植,对抑制对虾消化道弧菌数量、优化体内菌群组成和改善养殖环境有重要的作用。

A strain of lactic acid bacteria HN3 isolated from Litopenaeus vannamei digestive tract was used to conduct experiments to observe its antagonistic effect on two pathogenic vibrio species： Vibrio harveyi and Vibrio parahaemolyticus and its aquacultural effect on the growth of L. vannamei. The antagonism experiment showed that both the lactic acid bacteria HN3 and its extracellular fluid showed significantly different inhibitory effects a- gainst the growth of V. harveyi and V. parahaemolyticus. The aquaculture experiment showed that the daily gain rate （DGR）, survival rate （SR） and specific growth rate （SGR） of the shrimps fed the diet containing probiotic HN3 were significantly higher than those of the control （P 〈 0.05 ）. Similarly, significantly higher population density of the lactic acid bacteria and total bacteria were noted in the shrimp digestive tract and culture water compared to the control, but the number of Vibrio bacteria was reduced greatly （ P 〈 0.05 ）. The diet supple- mented with 4 × 106--5 × 106cfu · g-1 probiotic HN3 was the best to farm the shrimps, and the probiotic HN3 promoted the growth and improved the survival rate of the shrimps, which indicates that HN3 is adapted to the digestive tract environment, inhibits the growth of V. harveyi and V. parahaemolyticus and plays an important role in improving the composition of flora in the farming environment.