CNRS, UMR5557; Ecologie Microbienne, INRA, UMR1418, Université Lyon 1, 69220, Villeurbanne Cedex, France.
IMPMC, Institut de Recherche pour le Développement (IRD), UPMC, CNRS, MNHN, Noumea, New Caledonia, France.
Environ Microbiol. 2019 Apr;21(4):1407-1424. doi: 10.1111/1462-2920.14571. Epub 2019 Mar 19.
Mangroves are forest ecosystems located at the interface between land and sea where sediments presented a variety of contrasted environmental conditions (i.e. oxic/anoxic, non-sulfidic/sulfidic, organic matter content) providing an ideal ecosystem to study microbial communities with niche differentiation and distinct community structures. In this work, prokaryotic and fungal compositions were investigated during both wet and dry seasons in New Caledonian mangrove sediments, from the surface to deeper horizons under the two most common tree species in this region (Avicennia marina and Rhizophora stylosa), using high-throughput sequencing. Our results showed that Bacteria and Archaea communities were mainly shaped by sediment depth while the fungal community was almost evenly distributed according to sediment depth, vegetation cover and season. A detailed analysis of prokaryotic and fungal phyla showed a dominance of Ascomycota over Basidiomycota whatever the compartment, while there was a clear shift in prokaryotic composition. Some prokaryotic phyla were enriched in surface layers such as Proteobacteria, Euryarchaeota while others were mostly associated with deeper layers as Chloroflexi, Bathyarchaeota, Aminicenantes. Our results highlight the importance of considering fungal and prokaryotic counterparts for a better understanding of the microbial succession involved in plant organic matter decomposition in tropical coastal sediments.
红树林是位于陆地和海洋交界处的森林生态系统，其沉积物呈现出多种截然不同的环境条件（如好氧/缺氧、非硫化/硫化、有机质含量），为研究具有生态位分化和独特群落结构的微生物群落提供了理想的生态系统。在这项工作中，我们使用高通量测序技术，在新喀里多尼亚红树林沉积物中，对该地区两种最常见的树种（海桑和红海榄）的表层到深层，在干湿两季，分别研究了原核生物和真菌的组成。我们的结果表明，细菌和古菌群落主要受沉积物深度的影响，而真菌群落则根据沉积物深度、植被覆盖和季节几乎均匀分布。对原核生物和真菌门的详细分析表明，无论在哪个隔室，子囊菌门都超过担子菌门占优势，而原核生物的组成则发生了明显的变化。一些原核生物门在表层中富集，如变形菌门、广古菌门，而另一些则主要与深层有关，如绿弯菌门、深海古菌门、泉古菌门。我们的结果强调了考虑真菌和原核生物对应物的重要性，以便更好地理解热带沿海沉积物中植物有机质分解所涉及的微生物演替。
