Tabardillo Joselito A, Juinio-Meñez Marie Antonette, Reitzel Adam M, Ravago-Gotanco Rachel
The Marine Science Institute, College of Science, University of the Philippines Diliman, Quezon City, Philippines.
Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA.
BMC Microbiol. 2025 Jan 11;25(1):14. doi: 10.1186/s12866-024-03665-y.
The observed growth variability of different aquaculture species in captivity hinders its large-scale production. For the sandfish Holothuria scabra, a tropical sea cucumber species, there is a scarcity of information on its intestinal microbiota in relation to host growth, which could provide insights into the processes that affect growth and identify microorganisms with probiotic or biochemical potential that could improve current production strategies. To address this gap, this study used 16 S rRNA amplicon sequencing to characterize differences in gut and fecal microbiota among large and small juveniles reared in floating ocean nurseries.
We recovered 5915 amplicon sequence variants and diversity indices revealed significant differences between large and small juveniles (p < 0.05). Gut microbiota of large juveniles had lower bacterial diversity than its smaller counterparts. The genus cluster Burkholderia-Caballeronia-Paraburkholderia (BCP) is the most common and abundant taxa found in the gut for both size categories but less abundant in fecal samples. Small juveniles had a higher abundance of members from the Roseobacter clade (Rhodobacteriaceae) such as Ruegeria, Shimia, Psuedoruegeria and Marivita among others while the genus Schlegelella (Caldimonas) and Bosea were primarily found in larger juveniles. Predicted physiological functions identified signatures of metabolism, biosynthesis, and biodegradation pathways unique for each size category. Significant differences in diversity and composition were also exhibited between the pooled fecal and gut sample types.
The bacterial composition in the intestinal tract of the sandfish H. scabra is an important factor in the observed growth variability in aquaculture. The results show differences in diversity, composition and predicted physiological functions between the size groups, despite being from the same cohort and environment. It was also evident that the fecal microbiota differs from the gut and does not correspond to size category, warranting caution in using the fecal matter as a proxy to infer microbial composition and interactions in the gastrointestinal tract. Understanding the roles that these microorganisms play in sandfish growth could support the development of strategies to manage size variation in captive-bred sea cucumbers, or for the promotion and selection for faster-growing individuals.
圈养条件下不同水产养殖品种生长的变异性阻碍了其大规模生产。对于热带海参品种糙海参（Holothuria scabra），关于其肠道微生物群与宿主生长关系的信息匮乏，而这可能有助于深入了解影响生长的过程，并识别具有益生菌或生化潜力的微生物，从而改进当前的生产策略。为填补这一空白，本研究采用16S rRNA扩增子测序来表征在浮动海洋育苗场中饲养的大小不同的幼体肠道和粪便微生物群的差异。
我们获得了5915个扩增子序列变体，多样性指数显示大小幼体之间存在显著差异（p < 0.05）。大型幼体的肠道微生物群细菌多样性低于小型幼体。伯克霍尔德菌属-卡瓦列罗菌属-副伯克霍尔德菌属（BCP）菌群是在两种大小幼体的肠道中发现的最常见和丰富的分类群，但在粪便样本中含量较少。小型幼体中来自玫瑰杆菌属（红杆菌科）的成员丰度较高，如鲁杰氏菌属、希米亚菌属、假鲁杰氏菌属和玛丽维塔菌属等，而施莱格勒菌属（嗜热单胞菌属）和博斯氏菌属主要存在于大型幼体中。预测的生理功能确定了每个大小类别独特的代谢、生物合成和生物降解途径特征。合并的粪便和肠道样本类型之间在多样性和组成上也表现出显著差异。
糙海参肠道中的细菌组成是水产养殖中观察到的生长变异性的一个重要因素。结果表明，尽管来自同一群体和环境，但大小组之间在多样性、组成和预测的生理功能方面存在差异。同样明显的是，粪便微生物群与肠道不同，且与大小类别不对应，因此在使用粪便作为推断胃肠道微生物组成和相互作用的替代物时需谨慎。了解这些微生物在糙海参生长中所起的作用，有助于制定管理圈养海参大小差异的策略，或促进和选择生长更快的个体。
