嗜酸乳杆菌对3种弧菌的拮抗效果及对凡纳滨对虾肠道菌群结构的影响

Antagonism of Lactobacillus acidophilus against three Vibrio species and its influence on gut microbiota of Litopenaeus vannamei

使用益生菌是预防和控制水产养殖细菌感染的非抗生素方法之一。嗜酸乳杆菌(Lactobacillus acidophilus)可在机体内分泌抗菌物质,具有抑制有害菌生长、调节肠道微生态平衡和增强抗毒抗病能力等功能。研究了不同氧环境和不同培养基条件下嗜酸乳杆菌、副溶血弧菌(Vibrio parahaemolyticus)、哈维氏弧菌(V.harveyi)、溶珊瑚弧菌(V.coral-liilyticus)的生长情况,并通过牛津杯法和液体培养法结合PCR荧光定量技术、高通量测序技术,系统评价了嗜酸乳杆菌对上述弧菌的拮抗效果及对凡纳滨对虾(Litopenaeus vannamei)肠道菌群的组成和变化的影响。结果显示,在厌氧条件下,哈维氏弧菌的菌量显著高于在好氧环境培养后的菌量(P<0.05)。不同培养基配比对4种细菌的生长均具有显著性影响(P<0.05)。嗜酸乳杆菌对3种弧菌的生长均有良好的抑制效果。在对虾肠道菌群背景下,嗜酸乳杆菌对副溶血弧菌的生长有显著抑制作用(P<0.05)。处理组的弧菌属比例较对照组显著减少,高菌量组的有益菌属均显著增加。研究表明,嗜酸乳杆菌对上述3种弧菌的生长有良好的抑制效果,在对虾肠道菌群背景下对副溶血弧菌的生长也有良好的抑制效果,且能够优化菌群结构。

The use of probiotics is one of the non-antibiotic methods of preventing and controlling bacterial infections in aquaculture.Lactobacillus acidophilus can secrete antimicrobial substances in the body,which can inhibit the growth of harmful bacteria,regulate the micro-ecological balance of intestinal tract,and enhance the resistance to toxicity and disease.We analyzed the growth of L.acidophilus,Vibrio parahaemolyticus,V.harveyi and V.coralliilyticus under different oxygen environments and different media conditions,and systematically evaluated the antagonistic effect of L.acidophilus on the above mentioned Vibrio species,as well as the composition and changes of the intestinal flora of Litopenaeus vannamei,by using Oxford cup method and liquid culture method in addition with PCR fluorescence quantification and high throughput sequencing technology.The results show that anaero bic environment promoted the growth of V.harveyi significantly(P<0.05).Different ratios of media had a significant effect on the growth of all the four bacteria.L.acidophilus inhibited the growth of all the three Vibrio species effectively(P<0.05).In the background of intestinal flora of prawns,L.acidophilus inhibited the growth of V.parahaemolyticus significantly(P<0.05).The proportion of Vibrio spp.decreased significantly in the bacterial solution and supernatant groups compared with the control group.Beneficial genera of bacteria increased significantly in the high bacterial concentration group.The results indicate that L.acidophilus inhibits the growth of the above three Vibrio species in plate and liquid cultures,and inhibits the growth of V.parahaemolyticus in the background of prawn intestinal microbiota,being able to optimize the structure of microbiota.