Effects of dietary Bacillus baekryungensis on body wall nutrients, digestion and immunity of the sea cucumber Apostichopus japonicus

• Published in: Fisheries science 2023-03, Vol.89 (2), p.233-241
• Main Authors: Liu, Yue, Liu, Qiaosi, Bai, Qinglu, Wang, Liang, Li, Cheng, Li, Ying, Liu, Bingnan
• Format: Article
• Language: English
• Subjects: Acid phosphatase; Alkaline phosphatase; Amino acid composition; Amino acids; Apostichopus japonicus; Aquaculture; Bacillus; Biomedical and Life Sciences; Body wall; Body weight gain; Catalase; Conversion ratio; Digestibility; Digestion; Docosahexaenoic acid; Fatty acids; Feed conversion; Feeds; Fish & Wildlife Biology & Management; Food conversion; Food Science; Freshwater & Marine Ecology; Growth; Holothuroidea; Immunity; Life Sciences; Low temperature; Low temperature resistance; Lysozyme; Marine invertebrates; Nitric oxide; Nitric-oxide synthase; Nutrients; Nutritive value; Original Article; Overwintering; Phosphatase; Polyculture (aquaculture); Polyunsaturated fatty acids; Probiotics; Vegetables; α-Amylase
• ISSN: 0919-9268; 1444-2906
• DOI: 10.1007/s12562-022-01665-3

The purpose of this study was to assess the effects of a low temperature-resistant probiotic strain, Bacillus baekryungensis MS1, on the growth, nutritional quality, digestion and immunity of the sea cucumber Apostichopus japonicus under low temperature conditions. A feeding experiment was designed in which low (10 6  cfu/g) and high (10 8  cfu/g) doses of B. baekryungensis MS1 were added to the feed of sea cucumbers for 60 days; sea cucumbers not fed B. baekryungensis MS1 were used as controls. At the end of the experiment, the growth performance (including weight gain ratio, specific growth ratio and feed conversion ratio) of sea cucumbers fed the B. baekryungensis MS1-supplemented feed was significantly improved, in a dose-dependent manner. Also, the amino acid composition of the body wall had changed, and the total amino acid content had increased significantly. In addition, the content of polyunsaturated fatty acids, especially docosahexaenoic acid, had increased significantly, but no significant difference between the high- and low-dose groups was observed. The gut protease and α-amylase activities of sea cucumbers fed the B. baekryungensis MS1-supplemented diet were significantly increased. The activities of nitric oxide synthase, lysozyme, catalase, acid phosphatase and alkaline phosphatase were significantly higher in the high-dose group than in the low-dose group and the control group. In the challenge test with Vibrio splendidum , the mortality of sea cucumbers fed B. baekryungensis MS1 was significantly lower than that of the control group. Based on these results, we conclude that providing A. japonicus with B. baekryungensis MS1-supplemented feed (especially at the dose of 10 8  cfu/g) resulted in improved growth, changes in the nutrients in the body wall and enhanced digestibility and immunity at low temperatures; it also provided effective support for the healthy overwintering aquaculture of A. japonicus .