216 Chapter 7 Methanoperedens” MAGs revealed the potential for EET via MHC proteins or OmcZlike subunits, possibly forming nanowires (Figure 3 and 4). 'Ca. Methanoperedens sp.' strain BLZ2 [GCF 002487355.1] MnO2 MAG Methanoperedens 'Ca. Methanoperedens sp.' LFW-24 [GCA 902384525.1] 'Ca. Methanoperedens manganicus' [GCA 012026795.1] 'Ca. Methanoperedens sp.' Vercelli strain [GCA 905339155.1] 'Ca. Methanoperedens ferrireducens' [GCA 003104905.1] Sed MAG Methanoperedens 5 Sed MAG Methanoperedens 3 'Ca. Methanoperedens sp.' nzgw24 [GCA 023249105.1] 'Ca. Methanoperedens sp.' LFW-280_4 [GCA 902386255.1] 'Ca. Methanoperedens sp.' nzgw23 [GCA 023249275.1] 'Ca. Methanoperedens sp.' DeMMO4_29 [GCA 020062365.1] 'Ca. Methanoperedens sp.' S2.57 [GCA 022013335.1] 'Ca. Methanoperedens sp.' DeMMO5_32 [GCA 020062615.1] 'Ca. Methanoperedens sp.' KR11_N3.mb.44 [ZGCA 018899795.1] 'Ca. Methanoperedens sp.' N1.45 [GCA 022013355.1] 'Ca. Methanoperedens sp.' KR11_0.1_MetaG.mb.84 [GCA 018900975.1] Sed MAG Methanoperedens 2 Sed MAG Methanoperedens 1 'Ca. Methanoperedens sp.' LFW-280_2_2 [GCA 902386115.1] 'Ca. Methanoperedens sp.' LFW-280_1_1 [GCA 902386085.1] 'Ca. Methanoperedens sp.' Fe_173 [GCA 021409285.1] 'Ca. Methanoperedens manganireducens' [GCA 012026835.1] 'Ca. Methanoperedens sp.' LFW-280_3_2 [GCA 902386205.1] 'Ca. Methanoperedens sp.' LFW-280_3_1 [GCA 902386135.1] 'Ca. Methanoperedens Vercelli' (type strain) [GCF 900196725.1] 'Ca. Methanoperedens nitroreducens' (type strain) [GCF 000685155.1] 'Ca. Methanoperedens sp.' BE2012_43_12 [GCA 020724545.1] 'Ca. Methanoperedens sp.' HGW-Methanoperedenaceae-1 [GCA 002839545.1] 'Ca. Methanoperedens sp.' Kmv03 [GCA 014859785.1] 'Ca. Methanoperedens sp.' UBA10536 [GCA 013331375.1] 100 100 100 100 100 100 100 100 100 100 72 100 73 100 100 100 100 0.1 Metagenomic potential EET Experiment EET EET and/or NITRATE REDUCTION Experiment EET + Nitrate reduction Nitrate reduction Groundwater Iron-rich subsurface Sediment Iron Nitrate Manganese MnO2 environment Cadagno bioreact or Mud volcano SOURCE ENERGY CONSERVING HYDROGENASE Present Absent Co-existence: Methanoperedenaceae & Desulfobacterota c. QYQD01 Wetland 1 1 2 3 4 2 3 4 Figure 3. Phylogenomic tree of Methanoperedeneacae MAGs with Lake Cadagno representatives highlighted in bold. The tree has been generated using GTDB-Tk classification tools with multiple sequence alignments of 53 archaeal phylogenetic markers. Four MAGs that were not in the GTDB database at the time of analysis were additionally included: GCA_022013355.1 & GCA_022013335.1 (Bell et al., 2022) and GCA_020062615.1 & GCA_020062365.1 (Casar et al., 2021). Extracellular electron transfer (EET) and presence/absence of hydrogenases are only indicated for MAGs with shown or suspected EET. Branch lengths represent the average number of amino acid substitutions per site. Bootstrap values are shown for > 70% branching support. Distinct multi-heme c-type cytochrome (MHC) and OmcZ-like nanowires assigned to Lake Cadagno “Ca. Methanoperedens” spp. Intrigued by the high AOM activity in the manganese oxide incubation and the enrichment of “MnO2 MAG Methanoperedens”, we analyzed the metagenomes carefully for putative EET mechanisms. We investigated the amount, type, and similarity of MHC proteins plus their OmcZ-like subunits putatively forming conductive nanowire proteins (Figure 4, Supplementary Figure 3-4 and Supplementary Table 8). “MnO2 MAG Methanoperedens” and “Sed MAG
RkJQdWJsaXNoZXIy MTk4NDMw