■水产养殖动物在水中饲养,它们在整个生命周期中与各种微生物关系密切,因为其中一些微生物可能参与宿主的健康或生理。在水产养殖孵化场,了解天然海水微生物群之间存在的相互作用,饲养水微生物群,幼虫阶段和幼虫健康状况,可能允许建立微生物代理来监测饲养生态系统。的确,这些代理可以帮助确定虾幼虫发育的最佳微生物群,并最终帮助微生物管理。
■在这种情况下,我们监测了太平洋蓝虾对虾孵化场养殖水中活性微生物群的每日组成。分析了两种不同的饲养条件;一种将抗生素添加到饲养水中,一种不含抗生素。在这个饲养过程中,观察到存活率高的健康幼虫和死亡率高的不健康幼虫。利用水微生物群16SrRNA基因V4区的HiSeq测序,加上生态技术和统计分析,我们的目的是区分与特定幼虫阶段高死亡率相关的微生物类群。
■我们强调,无论幼虫的存活率如何,饲养水的活性微生物群都是高度动态的。在带有抗生素饲养的健康幼虫的水中与没有抗生素饲养的不健康幼虫之间,显示了微生物组成的明显区别。然而,很难解开抗生素添加和幼虫死亡对饲养水活性微生物群的影响。除了具有良好存活率的zoea外,饲养水的各种活性类群对给定的幼虫阶段和存活率具有特异性。将这些社区与泻湖的社区进行比较,似乎许多分类群最初是在天然海水中检测到的。这突出了泻湖的微生物组成对饲养水微生物群的重要性。考虑到幼虫的阶段和幼虫的生存,我们强调了几个属:Nautella,Leisingera,Ruegerira,Alconivorax,Marinobacter和Tenacibaculum,可能对幼虫的生存有益,在饲养的水中,克服了战略微生物和/或推定的病原体。这些属的成员也可能充当幼虫的益生菌。Marivita,Aestuariicoccus,HIMB11和Nioella,似乎不利于幼虫的生存,并且可能与即将发生的幼虫死亡有关。所有这些健康或不健康幼虫的特定生物标志物,可以用作天然海水中的早期常规检测代理,然后在幼虫饲养的第一天,并可能有助于管理饲养水的微生物群,并为幼虫选择有益的微生物。
Aquacultured animals are reared in water hosting various microorganisms with which they are in close relationships during their whole lifecycle as some of these microorganisms can be involved in their host\'s health or physiology. In aquaculture hatcheries, understanding the interactions existing between the natural seawater microbiota, the rearing water microbiota, the larval stage and the larval health status, may allow the establishment of microbial proxies to monitor the rearing ecosystems. Indeed, these proxies could help to define the optimal microbiota for shrimp larval development and could ultimately help microbial management.
In this context, we monitored the daily composition of the active microbiota of the rearing water in a hatchery of the Pacific blue shrimp Penaeus stylirostris. Two distinct rearing conditions were analyzed; one with antibiotics added to the rearing water and one without antibiotics. During this rearing, healthy larvae with a high survival rate and unhealthy larvae with a high mortality rate were observed. Using HiSeq sequencing of the V4 region of the 16S rRNA gene of the water microbiota, coupled with zootechnical and statistical analysis, we aimed to distinguish the microbial taxa related to high mortality rates at a given larval stage.
We highlight that the active microbiota of the rearing water is highly dynamic whatever the larval survival rate. A clear distinction of the microbial composition is shown between the water harboring heathy larvae reared with antibiotics versus the unhealthy larvae reared without antibiotics. However, it is hard to untangle the effects of the antibiotic addition and of the larval death on the active microbiota of the rearing water. Various active taxa of the rearing water are specific to a given larval stage and survival rate except for the zoea with a good survival rate. Comparing these communities to those of the lagoon, it appears that many taxa were originally detected in the natural seawater. This highlights the great importance of the microbial composition of the lagoon on the rearing water microbiota. Considering the larval stage and larval survival we highlight that several genera: Nautella, Leisingera, Ruegerira, Alconivorax, Marinobacter and Tenacibaculum, could be beneficial for the larval survival and may, in the rearing water, overcome the r-strategist microorganisms and/or putative pathogens. Members of these genera might also act as probiotics for the larvae. Marivita, Aestuariicocccus, HIMB11 and Nioella, appeared to be unfavorable for the larval survival and could be associated with upcoming and occurring larval mortalities. All these specific biomarkers of healthy or unhealthy larvae, could be used as early routine detection proxies in the natural seawater and then during the first days of larval rearing, and might help to manage the rearing water microbiota and to select beneficial microorganisms for the larvae.