Laboratory for Animal Nutrition and Immune Molecular Biology, College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, China.
Laboratory of Comparative Immunology, College of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China.
Fish Shellfish Immunol. 2020 Nov;106:1087-1094. doi: 10.1016/j.fsi.2020.08.049. Epub 2020 Sep 2.
Probiotics play vital roles in controlling diseases, enhancing specific and non-specific immunity and stimulating growth in the aquaculture industry. However, the effect of fermentation of feed by probiotics on the immune ability of sea cucumber has not been reported to date. Here, three candidate probiotic strains (Bacillus species) were isolated from the culture seawater and sediment of sea cucumber, and fishmeal and scallop mantle fermented by the candidate probiotic strains were used to feed sea cucumber. The results showed that the free amino acid and small peptide contents of the fishmeal and scallop mantle were significantly increased after fermentation for 72 h. However, the weight gain (WG) and specific growth rate (SGR) of sea cucumber showed no significant differences among the fermented fishmeal, fermented scallop mantle and control groups. Scallop mantle fermented by the three candidate probiotics could increase the coelomocyte number and respiratory burst activity. The immune-related enzymatic activity was increased after consuming the fermented fishmeal and scallop mantle, while the activity of antioxidant enzymes was reduced. The expression levels of immune- and antioxidant-related genes were changed after consuming the fermented fishmeal and scallop mantle. Taken together, our results suggest that probiotics could increase the immunocompetence of sea cucumber, and fermented scallop mantle might be a potential substitute for fishmeal during feed preparation. Our results lay a foundation for further understanding the relationship between probiotics and the non-specific immunity of sea cucumber.
益生菌在控制疾病、增强特异性和非特异性免疫以及刺激水产养殖业的生长方面发挥着重要作用。然而，到目前为止，益生菌对海参免疫能力的影响尚未有报道。在这里，我们从海参养殖海水和沉积物中分离出了 3 株候选益生菌（芽孢杆菌属），并使用候选益生菌发酵鱼粉和扇贝套膜来饲养海参。结果表明，经过 72 小时发酵后，鱼粉和扇贝套膜中的游离氨基酸和小肽含量显著增加。然而，发酵鱼粉、发酵扇贝套膜和对照组之间的海参体重增加（WG）和特定生长率（SGR）没有显著差异。三种候选益生菌发酵的扇贝套膜可增加体腔细胞数量和呼吸爆发活性。食用发酵鱼粉和扇贝套膜后，免疫相关酶的活性增加，而抗氧化酶的活性降低。免疫和抗氧化相关基因的表达水平在食用发酵鱼粉和扇贝套膜后发生了变化。综上所述，我们的结果表明益生菌可以提高海参的免疫能力，发酵的扇贝套膜可能是饲料制备中替代鱼粉的潜在替代品。我们的结果为进一步了解益生菌与海参非特异性免疫之间的关系奠定了基础。
