Small urban wetlands are widely distributed and susceptible to human activities, serving as important sources and sinks of carbon. Microorganisms play a crucial role in carbon cycle, while limited studies have been conducted on the microbial diversity in small urban wetlands and the functions of microbiome in carbon fixation and metabolism. To probe into the microbiome-driven carbon cycling in small urban wetlands and dissect the composition and functional groups of microbiome, we analyzed the relationships between the microbiome structure, element metabolism pathways, and habitat physicochemical properties in sediment samples across three small wetlands in Huzhou City, and compared them with natural wetlands in the Zoige wetland. High-throughput sequencing of 16S rRNA gene amplicons and metagenomics was employed to determine the species and functional groups. Sixty medium to high-quality metagenome-assembled genomes (MAGs) were constructed, including 55 bacterial and 5 archaeal taxa, and their potential in driving elemental cycles were analyzed, with a focus on carbon fixation. Several bacterial species were found to encode a nearly complete carbon fixation pathway, including the Calvin cycle, the reductive tricarboxylic acid cycle, the Wood-Ljungdahl pathway, and the reductive glycine pathway. There were several potential novel carbon-fixing bacterial members, such as those belonging to Syntrophorhabdus (Desulfobacterota) and UBA4417 (Bacteroidetes), which had high relative abundance in the wetland microbiome. Unveiling the genetic potential of these functional groups to facilitate element cycling is of great scientific importance for enhancing the carbon sequestration capacity of small urban wetlands.
Wetlands ; Microbiota/genetics* ; Carbon Cycle/genetics* ; Bacteria/classification* ; RNA, Ribosomal, 16S/genetics* ; China ; Cities ; Geologic Sediments/microbiology* ; Archaea/classification* ; Metagenomics ; Metagenome

As thermostable enzymes and organisms are much more needed, researches on heat shock proteins(HSPs) of hyperthermophilic archaea have drawn more concerns. HSPs from hyperthermophilic archaea are concise only with HSP60, sHSP, prefoldin and AAA+proteins, but without HSP100s, HSP90s, HSP70 (DnaK), HSP40 (DnaJ) and GrpE which are common in mesophilic or thermophilic archaea. Accordingly, studies on the structure, function and operation mechanism of these four groups are much more important and meaningful. This review focuses on the recent progress in the researchs on the structure, function, operation mechanism and cooperation of the HSPs from hyperthermophilic archaea. The problems and obfuscations in these HSPs are analyzed, and farther research direction and key points are put out.
Archaea ; classification ; metabolism ; Archaeal Proteins ; metabolism ; Chaperonin 60 ; metabolism ; Heat-Shock Proteins ; genetics ; metabolism ; Molecular Chaperones ; metabolism