Patwardhan Sushmita, Smedile Francesco, Giovannelli Donato, Vetriani Costantino
Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, United States.
National Research Council, Institute for Coastal Marine Environment, Messina, Italy.
Front Microbiol. 2021 Apr 6;12:638300. doi: 10.3389/fmicb.2021.638300. eCollection 2021.
Tor Caldara is a shallow-water gas vent located in the Mediterranean Sea, with active venting of CO and HS. At Tor Caldara, filamentous microbial biofilms, mainly composed of and , grow on substrates exposed to the gas venting. In this study, we took a metaproteogenomic approach to identify the metabolic potential and expression of central metabolic pathways at two stages of biofilm maturation. Our findings indicate that inorganic reduced sulfur species are the main electron donors and CO the main carbon source for the filamentous biofilms, which conserve energy by oxygen and nitrate respiration, fix dinitrogen gas and detoxify heavy metals. Three metagenome-assembled genomes (MAGs), representative of key members in the biofilm community, were also recovered. Metaproteomic data show that metabolically active chemoautotrophic sulfide-oxidizing members of the dominated the young microbial biofilms, while become prevalent in the established community. The co-expression of different pathways for sulfide oxidation by these two classes of bacteria suggests exposure to different sulfide concentrations within the biofilms, as well as fine-tuned adaptations of the enzymatic complexes. Taken together, our findings demonstrate a shift in the taxonomic composition and associated metabolic activity of these biofilms in the course of the colonization process.
托尔卡尔达拉是地中海中的一个浅水气体排放口，有一氧化碳和硫化氢的活跃排放。在托尔卡尔达拉，丝状微生物生物膜主要由[具体成分1]和[具体成分2]组成，生长在暴露于气体排放的基质上。在本研究中，我们采用宏蛋白质基因组学方法来确定生物膜成熟两个阶段的代谢潜力和中心代谢途径的表达。我们的研究结果表明，无机还原态硫物种是丝状生物膜的主要电子供体，一氧化碳是主要碳源，这些生物膜通过有氧呼吸和硝酸盐呼吸来保存能量，固定氮气并解毒重金属。还获得了三个代表生物膜群落关键成员的宏基因组组装基因组（MAGs）。宏蛋白质组学数据表明，年轻微生物生物膜中以代谢活跃的化学自养硫化物氧化的[具体细菌类群1]成员为主，而[具体细菌类群2]在成熟群落中变得普遍。这两类细菌不同的硫化物氧化途径的共表达表明生物膜内暴露于不同的硫化物浓度，以及酶复合物的精细调节适应。综上所述，我们的研究结果表明这些生物膜在定殖过程中分类组成和相关代谢活性发生了变化。
