Matis ohf, Icelandic Food and Biotech R&D, Vinlandsleid, Reykjavik, Iceland.
J Appl Microbiol. 2010 Nov;109(5):1775-89. doi: 10.1111/j.1365-2672.2010.04806.x. Epub 2010 Jul 21.
To study the effect of ova disinfection, antibiotic and microbial treatments on the dominant cultivable cod rearing microbiota at pre- and posthatch stages, determining some virulence-related phenotypic traits among bacterial isolates and their relation to larval survival.
Sampling of rearing systems (rearing water, ova, larvae, feeds and supplement) for analysis of cultivable microbiota took place at early stages in 2004 and 2005. Cultivation, phenotypic and genotypic (16S rRNA gene) analyses were performed. The production of putative virulence factors (PVFs), including haemolysin, siderophores and quorum-sensing signals, by bacterial isolates was investigated and related to larval survival. The study was performed during two spawning seasons, evaluating current hatchery practices (ova disinfection and antibiotic treatment of unhealthy larvae) and specific putative probiotics applied to ova and larvae or rotifers. A diversified microbiota (75 operational taxonomic units, OTUs) was observed in cod rearing systems influenced by the feeds and treatments, with prevailing γ-Proteobacteria prior to hatching towards a multiphyla microbiota posthatch. Phenotypic tests demonstrated the heterogeneity within some OTUs. Multivariate analysis of survival data in larval silos and the corresponding larval microbiota was used to divide the genotypic groups into beneficial/harmless and detrimental/opportunistic clusters. PVFs were common among the proposed detrimental/opportunistic OTUs.
The results clearly demonstrate the influence of exogeneous feeding and treatments on larval gastrointestinal microbiota and the role of bacteria in larval survival.
Increased understanding of the microbiota in rearing systems may contribute to successful implementation of microbial management in cod aquaculture.
研究卵消毒、抗生素和微生物处理对孵化前和孵化后鳕鱼养殖优势可培养菌群的影响，确定细菌分离株中一些与毒力相关的表型特征及其与幼虫存活率的关系。
2004 年和 2005 年初，对养殖系统（养殖水、卵、幼虫、饲料和补充剂）进行了取样，以分析可培养菌群。进行了培养、表型和基因型（16S rRNA 基因）分析。研究了细菌分离株产生潜在毒力因子（PVFs）的情况，包括溶血素、铁载体和群体感应信号，并将其与幼虫存活率相关联。这项研究在两个产卵季节进行，评估了当前孵化场的做法（卵消毒和不健康幼虫的抗生素处理）以及特定的潜在益生菌应用于卵和幼虫或轮虫。鳕鱼养殖系统中观察到了多样化的微生物群（75 个操作分类单位，OTUs），受饲料和处理的影响，孵化前以γ-变形菌为主，孵化后则为多菌群。表型测试表明了一些 OTUs 内部的异质性。对幼虫筒仓中生存数据和相应的幼虫微生物群的多元分析用于将基因型分组分为有益/无害和有害/机会性聚类。潜在的有害/机会性 OTUs 中常见 PVFs。
结果清楚地表明了外源喂养和处理对幼虫胃肠道微生物群的影响，以及细菌在幼虫存活中的作用。
增加对养殖系统中微生物群的理解可能有助于成功实施鳕鱼水产养殖中的微生物管理。
