饲料中添加潜在益生菌对凡纳滨对虾肠道消化酶活性和菌群组成的影响

在基础饲料中添加不同配伍的坚强芽孢杆菌Bacillus firmus活菌（1.0×108CFU/g）、美人鱼发光杆菌Photobacterium damsela灭活菌（1%）和溶藻弧菌Vibrio alginolyticus灭活菌（1%）作为实验饲料，基础饲料为对照组。实验所用凡纳滨对虾初始质量为3.2±0.26 g，投喂15d后进行WSSV感染实验并继续观察14d。实验期间定期取样测定对虾肠道胃蛋白酶、脂肪酶和淀粉酶的活性变化，并分析可培养肠道细菌总数和优势菌数量。结果表明，实验组对虾肠道中胃蛋白酶、脂肪酶和淀粉酶活性整体水平均显著高于对照组（P<0.05），肠道细菌数量较对照组有显著增加。其中，坚强芽孢杆菌与美人鱼发光杆菌灭活菌复合菌组具有最高的淀粉酶活性，坚强芽孢杆菌与溶藻弧菌灭活菌复合组具有最高的脂肪酶和胃蛋白酶活性，而坚强芽孢杆菌单一组具有最大的肠道细菌总数和优势菌数。本研究表明，饲料中添加潜在益生菌可以提高凡纳滨对虾肠道消化酶活性并调节肠道菌群变化，利于养分的消化吸收。其中以坚强芽孢杆菌与美人鱼发光杆菌灭活菌复合组的整体效果较佳。

Potential probiotics supplement may impact intestinal digestive enzyme and bacteria composition of Litopenaeus vannamei

In this study, the influence of three intestinal potential probiotics, Bacillus firmus, Photobacterium damsela, and Vibrio alginolyticus supplementation was investigated on digestive enzyme activities (pepsin, lipase and amylase) and intestinal bacteria of Litopenaeus vannamei. Probiotic B. firmus (live, 1.0×108CFU/g) tandem 1% P. damsela (inactivated), probiotic B. firmus (live, 1.0×108CFU/g) only, or probiotic B. firmus (live, 1.0×108CFU/g) tandem 1% V. alginolyticus (inactivated) was added to the basic feed for the treatments. No probiotic was supplemented to the control. Mean digestive enzyme activities of all probiotic treatments were significantly different (P<0.05) from that of the control. Besides, total and dominant bacterial counts in probiotic-supplemented groups were different from that in the control. The B. firmus + P. damsela treatment demonstrated the highest amylase activity; the B. firmus + V. alginolyticus treatment demonstrated the highest lipase and pepsin activity; the B. firmus only treatment demonstrated the greatest numbers of total and dominant bacterial counts. It was found that supplementation of probiotics to the basic feed could significantly increased digestive enzyme activities and improve the shrimp''s intestinal flora. The multispecies probiotics showed better effect.