饲料添加益生菌对多病原阳性的凡纳滨对虾生长与存活的影响

Effects of Probiotics-Supplemented Diets on the Growth and Survival of Litopenaeus vannamei Carrying Multiple Pathogens

中文关键词: 凡纳滨对虾  益生菌  生长  存活  多病原带毒

英文关键词: Litopenaeus vannamei  Probiotics  Growth  Survival  Positive multiple pathogens

中文摘要:

      采用假交替单胞菌(Pseudoalteromonas sp.) KL-3 2010和微小杆菌(Exiguobacterium sp.) KL-C2 2014作为益生菌，进行凡纳滨对虾(Litopenaeus vannamei)投喂实验，研究上述菌株对带毒对虾的生长与存活的影响。假交替单胞菌KL-3 2010对致急性肝胰腺坏死副溶血弧菌(Vibrio parahemolyticus) (VPAHPND 20130629002S01)有拮抗作用和胞外蛋白酶活性，微小杆菌KL-C2 2014有胞外蛋白酶活性。待试对虾经检测为白斑综合征病毒(WSSV)、致急性肝胰腺坏死病副溶血弧菌(VPAHPND)和虾肝肠胞虫(EHP)弱阳性。经过为期60 d的养殖实验，结果显示，与投喂普通颗粒饲料的对照组相比，投喂假交替单胞菌KL-3 2010的对虾存活率提高了213%±43% (P<0.01)；投喂微小杆菌KL-C2 2014的对虾平均生长率提高了105.5%±28.1% (P<0.05)；交替投喂2株菌的对虾存活率提高了184%±52% (P<0.05)，平均生长率提高了70.6%±32.8%。肠道可培养优势菌研究表明，2株益生菌的投喂显著影响了对虾肠道优势菌群的种类。本研究为带毒虾苗的养殖提供一种有效的病害防控和促生长的手段。

英文摘要:

      Current shrimp farming industries face difficulties associated with disease outbreak caused by pathogens on shrimp larva. The application of probiotics may provide a solution to problems associated with disease. We used Pseudoalteromonas sp. strain KL-3 2010, which has antagonism against acute hepatopancreatic necrosis disease-causing Vibrio parahaemolyticus (VPAHPND) and extracellular protease activity, and Exiguobacterium sp. strain KL-C2 2014, which has extracellular protease activity, as probiotics in a feeding test of Litopenaeus vannamei to investigate their effects on the growth and survival of shrimp. These two bacterial strains had no pathogenicity to L. vannamei in an immersion challenge at 108 CFU/ml. Weak positive signals for white spot syndrome (WSSV), VPAHPND, and Enterocytozoon hepatopenaei (EHP) were detected in the population of shrimp juveniles used in this study. L. vannamei was fed for 60 days with Pseudoalteromonas sp. KL-3 2010-supplemented diets (P group), Exiguobacterium sp. KL-C2 2014-supplemented diets (E group), alternation of the two diets (PE group), and normal diets (C group), respectively. Compared with the control group, the survival rate of the P group significantly improved (by 213%±43%; P<0.01), the average growth rate of E group significantly increased (by 105.5%±28.1%; P<0.05), and the survival rate and average growth rate of the PE group simultaneously improved (by 184%±52%; P<0.05 and by 70.6%±32.8%, respectively). Feeding with Pseudoalteromonas sp. KL-3 2010 and Exiguobacterium sp. KL-C2 2014 diets significantly affected the species of dominant microflora colonizing the shrimp gut, but these added probiotic bacterial strains were not detected in the re-isolated and cultivated dominant bacteria colonies. The addition with these probiotics to diets significantly increased some serum immune indexes, such as superoxide dismutase. The study showed that diets supplemented with the above probiotics may provide a practical approach for disease prevention and growth promotion in shrimp farming, even for shrimp positive for multiple pathogens.