Yasin Ina-salwany Md, Razak Nabilah Fatin, Natrah F M I, Harmin Sharr Azni
J Environ Biol. 2016 Jul;37(4 Spec No):791-800.
A total of 58 Gram-positive bacteria strains were isolated from the marine environment and screened for potential probiotics for disease prevention and improving the productivity of tiger grouper Epinephelus fuscoguttatus larvae and juveniles. The bacteria were identified as Bacillus licheniformis, B. subtilis, B. circulans, B. sphaericus, B. cereus, Brevibacillus brevis, Corynebacterium propinquum, Leifsonia aquatica and Paenibacillus macerans. Only 24 strains showed antagonistic activities against four pathogenic strains; Vibrio alginolyticus, V. harveyi, V. parahaemolyticus and Aeromonas hydrophila, where two of the Bacillus strains, B12 and B45 demonstrated intermediate to highest level of inhibitory activity against these pathogenic strains, respectively. Further assessment by co-culture assay showed that Bacillus strain B12 exhibited a total inhibition of V. alginolyticus, while B45 strain displayed no inhibitory activity. Mixed culture of Bacillus B12 and B45 strains to outcompete V. alginolyticus was observed at a cell density of 10(7) CFU ml(-1). Molecular identification and phylogenetic tree analysis have categorized Bacillus strain B12 to the reference strains GQ340480 and JX290193 of? B. amyloliquafaciens, and Bacillus strain B45 with a reference strain JF496522 of B. subtilis. Safety tests of probionts by intraperitoneal administration of B12 and B45 strains at cell densities of 103, 105 and 10(7) CFU ml(-1) revealed no abnormalities and cent percent survival for healthy Epinephelus fuscoguttatus juveniles within 15 days of experimental period. Overall, the study revealed that Bacillus B12 strain possesses tremendous probiotic potential that could be used as a feed supplement in tiger grouper diets. ?
从海洋环境中总共分离出58株革兰氏阳性细菌菌株，并筛选其作为潜在益生菌用于疾病预防以及提高虎斑石斑鱼幼鱼和成鱼的生产力。这些细菌被鉴定为地衣芽孢杆菌、枯草芽孢杆菌、环状芽孢杆菌、球形芽孢杆菌、蜡样芽孢杆菌、短短芽孢杆菌、近平棒杆菌、水生利夫森菌和浸麻芽孢杆菌。只有24株菌株对四种病原菌，即溶藻弧菌、哈维氏弧菌、副溶血性弧菌和气单胞菌具有拮抗活性，其中两株芽孢杆菌菌株B12和B45分别对这些病原菌表现出中等至最高水平的抑制活性。通过共培养试验进一步评估表明，芽孢杆菌菌株B12对溶藻弧菌具有完全抑制作用，而B45菌株没有抑制活性。在细胞密度为10(7) CFU ml(-1)时，观察到芽孢杆菌B12和B45菌株混合培养以胜过溶藻弧菌。分子鉴定和系统发育树分析已将芽孢杆菌菌株B12归类为解淀粉芽孢杆菌的参考菌株GQ340480和JX290193，芽孢杆菌菌株B45与枯草芽孢杆菌的参考菌株JF496522归为一类。通过以103、105和10(7) CFU ml(-1)的细胞密度腹腔注射B12和B45菌株进行益生菌安全性测试，结果显示在实验期15天内，健康的虎斑石斑鱼幼鱼没有出现异常，存活率为百分之百。总体而言，该研究表明芽孢杆菌B12菌株具有巨大的益生菌潜力，可作为虎斑石斑鱼饲料添加剂使用。
