Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France.
Ifremer, Univ Brest, CNRS, IRD, LEMAR, F-29280 Plouzané, France.
FEMS Microbiol Ecol. 2020 Aug 1;96(8). doi: 10.1093/femsec/fiaa078.
Digestive microbiota provide a wide range of beneficial effects on host physiology and are therefore likely to play a key role in marine intertidal bivalve ability to acclimatize to the intertidal zone. This study investigated the effect of intertidal levels on the digestive bacterial microbiota of oysters (Crassostrea gigas) and clams (Ruditapes philippinarum), two bivalves with different ecological niches. Based on 16S rRNA region sequencing, digestive glands, seawater and sediments harbored specific bacterial communities, dominated by operational taxonomic units assigned to the Mycoplasmatales,Desulfobacterales and Rhodobacterales orders, respectively. Field implantation modified digestive bacterial microbiota of both bivalve species according to their intertidal position. Rhodospirillales and Legionellales abundances increased in oysters and clams from the low intertidal level, respectively. After a 14-day depuration process, these effects were still observed, especially for clams, while digestive bacterial microbiota of oysters were subjected to more short-term environmental changes. Nevertheless, 3.5 months stay on an intertidal zone was enough to leave an environmental footprint on the digestive bacterial microbiota, suggesting the existence of autochthonous bivalve bacteria. When comparing clams from the three intertidal levels, 20% of the bacterial assemblage was shared among the levels and it was dominated by an operational taxonomic unit affiliated to the Mycoplasmataceae and Spirochaetaceae families.
消化微生物群为宿主生理提供了广泛的有益影响，因此很可能在海洋潮间带双壳类动物适应潮间带的能力中发挥关键作用。本研究调查了潮间带水平对牡蛎（Crassostrea gigas）和蛤（Ruditapes philippinarum）两种生态位不同的双壳类动物消化细菌微生物群的影响。基于 16S rRNA 区域测序，消化腺、海水和沉积物中分别存在特定的细菌群落，主要由归属于支原体目、脱硫杆菌目和红杆菌目的操作分类单元组成。现场植入根据双壳类动物的潮间带位置改变了两种双壳类动物的消化细菌微生物群。来自低潮间带的牡蛎和蛤中的 Rhodospirillales 和 Legionellales 的丰度增加。经过 14 天的净化过程，仍然可以观察到这些影响，尤其是在蛤中，而牡蛎的消化细菌微生物群更容易受到短期环境变化的影响。然而，在潮间带停留 3.5 个月足以在消化细菌微生物群上留下环境痕迹，表明存在本土双壳类细菌。当比较来自三个潮间带水平的蛤时，水平之间有 20%的细菌组合是共享的，并且它主要由一个归属于支原体科和螺旋体科的操作分类单元组成。
