Zhang Wan, Che Jian, Sun Xiaowen, Murtaza Bilal, Li Tingfang, Li Xiaoyu, Wang Lili, Xu Yongping
MOE Key Laboratory of Bio-Intelligent Manufacturing, School of Bioengineering, Dalian University of Technology, Dalian, 116024, China.
MOE Key Laboratory of Bio-Intelligent Manufacturing, School of Bioengineering, Dalian University of Technology, Dalian, 116024, China; Dalian Xinyulong Marine Biological Seed Technology Co., Ltd., Dalian, 116222, China.
Fish Shellfish Immunol. 2025 Nov;166:110620. doi: 10.1016/j.fsi.2025.110620. Epub 2025 Aug 5.
The antibacterial efficacy of yeast glycoprotein (YG) against Vibrio alginolyticus (VA) and its potential benefits for sea cucumber (Apostichopus japonicus) health and growth were investigated. A total of 844 proteins were identified in YG, with the top 30 ranked by iBAQ (intensity-based Absolute Quantification, a metric reflecting protein abundance) values for further analysis. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of YG against V. alginolyticus were determined as 50 mg/mL and 25 mg/mL, respectively. Oxford cup assays revealed concentration-dependent antibacterial effects, with inhibition zones ranging from 6.03 mm to 14.86 mm. Transmission electron microscopy (TEM) observations demonstrated that YG treatment disrupted bacterial cell walls, causing membrane damage and leakage of intracellular contents. Enzyme activity assays further confirmed YG-induced bacterial lysis, as indicated by increased alkaline phosphatase (AKP) levels. Additionally, YG significantly reduced bacterial surface hydrophobicity, impairing adhesion capacity. Feeding trials demonstrated that dietary supplementation with YG enhanced immune enzyme activities, including lysozyme, catalase, and nitric oxide synthase, in sea cucumber coelomic fluid. Growth performance parameters such as specific growth rate (SGR) and feed conversion efficiency (FCE) improved significantly with YG supplementation. In a bacterial challenge experiment, cumulative survival rates increased to 53.33 % in the YG-treated groups compared to the positive control. Intestinal microbiota analysis showed that YG supplementation modified gut microbial composition, reducing species diversity. Histopathological observations indicated reduced tissue damage in YG-fed sea cucumbers post-infection. These findings suggest that YG exhibits strong antibacterial activity and immunomodulatory effects, making it a promising dietary supplement for enhancing disease resistance and growth performance in sea cucumbers.
研究了酵母糖蛋白（YG）对溶藻弧菌（VA）的抗菌效果及其对海参（刺参）健康和生长的潜在益处。在YG中总共鉴定出844种蛋白质，根据iBAQ（基于强度的绝对定量，一种反映蛋白质丰度的指标）值对排名前30的蛋白质进行进一步分析。YG对溶藻弧菌的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）分别确定为50mg/mL和25mg/mL。牛津杯法显示出浓度依赖性抗菌作用，抑菌圈范围为6.03mm至14.86mm。透射电子显微镜（TEM）观察表明，YG处理破坏了细菌细胞壁，导致细胞膜损伤和细胞内内容物泄漏。酶活性测定进一步证实了YG诱导的细菌裂解，碱性磷酸酶（AKP）水平升高表明了这一点。此外，YG显著降低了细菌表面疏水性，损害了粘附能力。投喂试验表明，在海参体腔液中添加YG可提高免疫酶活性，包括溶菌酶、过氧化氢酶和一氧化氮合酶。添加YG后，特定生长率（SGR）和饲料转化效率（FCE）等生长性能参数显著提高。在细菌攻毒实验中，与阳性对照组相比，YG处理组的累积存活率提高到了53.33%。肠道微生物群分析表明，添加YG改变了肠道微生物组成，降低了物种多样性。组织病理学观察表明，YG投喂的海参在感染后组织损伤减轻。这些发现表明，YG具有很强的抗菌活性和免疫调节作用，使其成为一种有前途的膳食补充剂，可增强海参的抗病能力和生长性能。
