投喂盐富饶菌Haloferax YC-6强化卤虫对凡纳滨对虾生长和抗逆能力的影响

Effects of Haloferax YC-6-Enriched Artemia Feeding on Growth Performance and Stress Tolerance of Litopenaeus vannamei

通过生物饵料卤虫(Artemia)强化的方式研究红色古菌盐富饶菌(Haloferax YC-6)对凡纳滨对虾(Litopenaeus vannamei)生长、肠道菌群和抗逆能力的影响.将凡纳滨对虾仔虾6000尾随机分为2组,每组3个重复,每个重复1000尾虾.各组分别投喂饥饿卤虫(对照组)和Haloferax强化卤虫(实验组)养殖10 d后,测定对虾生长、营养组成、肠道菌群结构和丰度.测定对虾在氨氮胁迫和副溶血弧菌攻毒后的存活率,以及氨氮胁迫后对虾肝胰腺过氧化氢酶(CAT)的活性和丙二醛(MDA)含量.结果表明:投喂Haloferax强化卤虫的对虾存活率和体长显著高于对照组(P<0.05);Haloferax的摄入改变了对虾肠道菌群门水平的相对丰度,降低了弧菌属(Vibrio)的相对丰度;Haloferax的摄入显著提高了对虾肝胰腺CAT活性,显著降低了MDA含量(P<0.05).氨氮胁迫48 h后,实验组对虾的存活率显著高于对照组,CAT活性和MDA含量显著降低(P<0.05).弧菌攻毒后,实验组对虾的存活率显著高于对照组(P<0.05).因此,用Haloferax强化卤虫投喂对虾可显著提高其存活率,促进对虾生长,改善其肠道菌群组成,提高对虾的抗逆能力.

The effect of red archaea Haloferax on the growth performance,intestinal microbiota and stress resistance of Litopenaeus vannamei postlarvae was investigated through live feed Haloferax-enriched Artemia.A total of 6000 shrimp PLs were divided into two groups and were fed Haloferax-enriched Artemia nauplii(Hfx)and starved Artemia nauplii(Ctrl),respectively,with three replicates per group and 1000 individuals per replicate.After 10 days rearing,the growth,nutritional composition,intestinal microbiota structure and abundance of shrimp were determined.The shrimp were also exposed to ammonia nitrogen stress and Vibrio parahaemolyticus challenge,and the catalase(CAT)activity and malondialdehyde(MDA)content in hepatopancreas were measured after the ammonia nitrogen stress.The results showed that the survival rate and body length of shrimp PLs in the Hfx group were significantly higher than the Ctrl group(P<0.05).Compared with the Ctrl group,the intestinal microbiota composition had changed and the relative abundance of Vibrio decreased in the Hfx group.The CAT activity in the hepatopancreas in the Hfx group was significantly higher than the Ctrl group,while the MDA content significantly decreased(P<0.05).After being exposed to ammonia nitrogen for 48 h,the PLs in the Hfx group had significantly higher survival rate than the Ctrl group,which the CAT activity and MDA content in hepatopancreas significantly decreased(P<0.05).After challenged by Vibrio parahaemolyticus for 48 h,the Hfx group had significantly higher survival rate than the Ctrl group(P<0.05).In conclusion,the red archaea Haloferax supplement through Artemia bioencapsulation can enhance the survival and growth,benefit the intestinal microbiota diversity,and increase the resistance to ammonia nitrogen stress and Vibrio challenge of L.vannamei postlarvae.