Department of Biotechnology, Goa University, Taleigao Plateau, Goa, 403206, India.
Probiotics Antimicrob Proteins. 2019 Dec;11(4):1309-1323. doi: 10.1007/s12602-018-9503-y.
Development of probiotics to improve the growth of cultured species is a key to sustainable aquaculture. The present study investigates the potential of salt pan bacteria as probiotics for Litopenaeus vannamei. Halotolerant bacteria (100) were screened for enzyme production and mucus adhesion in vitro. The bacteria (SK07, SK27, ABSK55, FSK444, TSK17, TSK71) exhibiting promising enzyme activity and adhesive property in vitro were selected to study their effect on the growth and metabolism of L. vannamei in vivo. When administered to shrimps individually as a water additive in experiment I, SK07, SK27 and TSK71 significantly (p < 0.05) increased shrimp weight as compared to the control. In experiment II, a lyophilized bacterial consortium (test) prepared with the four best isolates (SK07, SK27, ABSK55, TSK71), exhibited significantly higher weight gain of shrimps, better feed efficiency and final yield as compared to control. Total enzyme activity (amylase, protease, lipase) in the shrimp gut was significantly higher in the test than the control. The four isolates showed 99% nBLAST similarity with Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis and Pseudomonas sp. Presence of these bacteria in the shrimp gut was confirmed by using specific PCR-based molecular probes and 16S rDNA sequencing. Safety evaluation by antibiotic susceptibility test and hemolytic activity test indicated that the bacteria are safe as bioinoculants. The increased enzyme activity by colonisation of the isolates in the shrimp gut, along with improved growth and feed utilisation efficiency, strongly confirms that these salt pan bacteria are prospective probiotics in shrimp aquaculture.
开发可改善养殖品种生长的益生菌是可持续水产养殖的关键。本研究调查了盐田细菌作为凡纳滨对虾益生菌的潜力。从耐盐细菌中筛选出具有体外产酶和黏液黏附能力的细菌（100 株）。选择体外表现出良好产酶活性和黏附特性的细菌（SK07、SK27、ABSK55、FSK444、TSK17、TSK71），研究其对凡纳滨对虾体内生长和代谢的影响。在实验 I 中，将这些细菌作为水添加剂单独投喂虾，与对照组相比，SK07、SK27 和 TSK71 显著（p<0.05）增加了虾的体重。在实验 II 中，用 4 株最佳分离株（SK07、SK27、ABSK55、TSK71）制备的冻干细菌混合物（试验组），与对照组相比，虾的增重、饲料效率和最终产量显著提高。虾肠道中的总酶活性（淀粉酶、蛋白酶、脂肪酶）在试验组中明显高于对照组。这 4 株分离株与枯草芽孢杆菌、解淀粉芽孢杆菌、地衣芽孢杆菌和假单胞菌的 nBLAST 相似度达到 99%。使用特异性 PCR 分子探针和 16S rDNA 测序证实了这些细菌存在于虾肠道中。抗生素敏感性试验和溶血活性试验的安全性评估表明，这些细菌作为生物接种剂是安全的。这些分离株在虾肠道中的定植增加了酶活性，并改善了生长和饲料利用效率，这强烈证实了这些盐田细菌是虾类养殖中有前景的益生菌。
