Host Gut-Derived Probiotic, Exiguobacterium acetylicum G1-33, Improves Growth, Immunity, and Resistance to Vibrio harveyi in Hybrid Grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂)

作者：Mingqing Zhang, Yuwei Feng, Zhongxuan Zhong, Qianping Du, Wei Yu, Jin‐Hui Wu, Xiaolin Huang, Zhong Huang, Guangting Xie, Hu Shu · 发表于：Microorganisms · 年份：2024 · DOI：10.3390/microorganisms12081688 · 被引用次数：12 · 研究领域：Aquaculture disease management and microbiota、Aquaculture Nutrition and Growth、Aquatic life and conservation

Several exogenous probiotics are applicable in fish culture; however, challenges in isolation and verification have hindered the full utilization of numerous host probiotics. Therefore, this study aimed to apply the host probiotic Exiguobacterium acetylicum G1-33 to hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) cultures and explore its mechanism of action. In total, 360 hybrid grouper were divided into four groups, which were fed the following for 60 days: three received commercial feed with varying concentrations of E. acetylicum G1-33 (106, 108, and 1010 CFU/g), while a control group received commercial feed. The results showed that supplementation with 106 and 108 CFU/g of E. acetylicum G1-33 enhanced gut morphology, upregulated growth-related genes (ghr1, igf-2, s6k1, tor), and promoted growth, with supplementation with 108 CFU/g resulting in the most notable enhancement. However, supplementation with 1010 CFU/g inhibited growth, possibly because of changes in intestinal morphology. Additionally, supplementation with E. acetylicum G1-33 upregulated the expression of immune-related genes (c3, myd88, Cu/Zn-sod, tlr3, and tnf2) in the liver and head kidney but led to an increase in malondialdehyde content, as well as a decrease in alkaline phosphatase and acid phosphatase activities, in the liver and serum, indicating increased oxidative stress. Moreover, supplementation with 106 and 108 CFU/g E. acetylicum G1-33 enhanced the widespread expression ...