Puente-Sánchez Fernando, Macías-Pérez Luis Alberto, Campbell Karley L, Royo-Llonch Marta, Balagué Vanessa, Sánchez Pablo, Tamames Javier, Mundy Christopher John, Pedrós-Alió Carlos
Department of Systems Biology Centro Nacional de Biotecnología, CSIC Madrid Spain.
Microbial Ecology Division, Department of Aquatic Sciences and Assessment Swedish University of Agricultural Sciences Uppsala Sweden.
Ecol Evol. 2024 Jun 18;14(6):e11546. doi: 10.1002/ece3.11546. eCollection 2024 Jun.
Microbial assemblages under the sea ice of the Dease Strait, Canadian Arctic, were sequenced for metagenomes of a small size fraction (0.2-3 μm). The community from early March was typical for this season, with - and Gammaproteobacteria as the dominant taxa, followed by Thaumarchaeota and Bacteroidetes. Toward summer, Bacteroidetes, and particularly the genus , became increasingly dominant, followed by the Gammaproteobacteria. Analysis of genes responsible for microbial acquisition of iron showed an abundance of ABC transporters for divalent cations and ferrous iron. The most abundant transporters, however, were the outer membrane TonB-dependent transporters of iron-siderophore complexes. The abundance of iron acquisition genes suggested this element was essential for the microbial assemblage. Interestingly, Gammaproteobacteria were responsible for most of the siderophore synthesis genes. On the contrary, Bacteroidetes did not synthesize siderophores but accounted for most of the transporters, suggesting a role as cheaters in the competition for siderophores as public goods. This cheating ability of the Bacteroidetes may have contributed to their dominance in the summer.
对加拿大北极地区迪斯海峡海冰下的微生物群落进行了测序，分析了小尺寸部分（0.2 - 3微米）的宏基因组。3月初的群落是该季节的典型群落，以γ-变形菌纲为主要分类群，其次是奇古菌门和拟杆菌门。到了夏季，拟杆菌门，特别是[具体属名缺失]属，变得越来越占优势，其次是γ-变形菌纲。对负责微生物获取铁的基因分析表明，存在大量用于二价阳离子和亚铁离子的ABC转运蛋白。然而，最丰富的转运蛋白是铁载体复合物的外膜依赖TonB的转运蛋白。铁获取基因的丰富表明该元素对微生物群落至关重要。有趣的是，γ-变形菌纲负责大部分铁载体合成基因。相反，拟杆菌门不合成铁载体，但占了大部分转运蛋白，这表明它们在作为公共物品的铁载体竞争中扮演着作弊者的角色。拟杆菌门的这种作弊能力可能促成了它们在夏季的优势地位。
