Abstract: To compare the metabolic status of exogenous Lactobacillus plantarum in the intestine of tilapia and zebrafish juvenile fish, tilapia or zebrafish juvenile fish were immersed with 104  cfu/mL, 105  cfu/mL, 106  cfu/mL, 107 cfu/mL Lactobacillus plantarum JCM1149 for 3 d and the whole intestines were sampled. In another experiment, tilapia or zebrafish juvenile fish were immersed with 107 cfu/mL Lactobacillus plantarum  JCM1149 for 7 d. The intestines were sampled at 0 h, 4 h, 12 h, 1 d, 2 d, 3 d, 4 d, and 5 d after immersion. The intestine samples were homogenized, and the absolute abundance of exogenous Lactobacillus plantarum in tilapia and zebrafish juvenile fish was evaluated by spread plate method and compared. The results indicated that after 3 d immersion, the absolute abundance of adhesive Lactobacillus plantarum in tilapia intestine did not change with the increasing immersion concentration above 105 cfu/mL, while the absolute abundance of adhesive Lactobacillus plantarum in zebrafish intestine was increased with the increasing immersion concentration up to 107 cfu/mL (P<0.05). After 7 d immersion, the levels of adhesive Lactobacillus plantarum decreased in both intestines of tilapia and zebrafish (P<0.01). Notably, the release of Lactobacillus plantarum was more rapidly in zebrafish, because one order of magnitude reduction in the level of intestinal Lactobacillus plantarum was observed at 24 h in tilapia, while 2 orders of magnitude reduction were observed at 24 h in zebrafish. These results indicated that variations existed in the metabolism of Lactobacillus plantarum in different fish hosts.

Key words: Lactobacillus plantarum, adhesive, plate counting, metabolism in intestine

摘要： 为比较外源添加植物乳杆菌在罗非鱼、斑马鱼幼鱼肠内的代谢情况，用104 cfu/mL、105 cfu/mL、106 cfu/mL及107 cfu/mL 4个浓度植物乳杆菌JCM1149分别浸浴罗非鱼、斑马鱼幼鱼3 d后取全肠，另外用107 cfu/mL植物乳杆菌JCM1149分别浸浴罗非鱼、斑马鱼幼鱼7 d，在浸浴结束后0 h、4 h、12 h、1 d、2 d、3 d、4 d、5 d取全肠。将各肠道样本匀浆处理涂板计数，比较罗非鱼与斑马鱼幼鱼肠内植物乳杆菌的代谢情况。结果显示，浸浴3 d后，对比不同浓度下肠内植物乳杆菌绝对丰度变化，当浓度大于105 cfu/mL，罗非鱼肠内植物乳杆菌绝对丰度无显著性差异，然而，斑马鱼肠内植物乳杆菌绝对丰度随浸浴浓度增加而显著升高（P<005）；以107 cfu/mL浸浴7 d后，罗非鱼与斑马鱼肠内植物乳杆菌均显著降低（P<0.01），其中斑马鱼表现更为迅猛，24 h时降低2个数量级，罗非鱼则只降低1个数量级。上述结果表明，植物乳杆菌鱼类肠内代谢存在明显的宿主差异性。

关键词: 植物乳杆菌, 黏附, 平板法测定, 肠内代谢