Table 2.
Medium and high quality MAGs affiliated to Methylococcales in Lake Lovojärvi as well as their genes encoding enzymes involved in microaerobic (i.e. oxygen scavenging and high-affinity oxidases) and anaerobic metabolism (i.e. NOx− reduction [denitrification], extracellular electron transfer [EET, i.e. electron transfer to Fe3+ and Mn4+ minerals and organic EAs] and fermentation) in Lovojärvi. The MAGs are ordered based on their vertical distribution pattern group (see Table 1). Full names of the enzymes are provided in table footnote1.
| MAG | Vertical distribution group | NO3− → NO2− | NO2− → NO | NO → N2O | EET genes | Fermentation | Microaerobic metabolism |
|---|---|---|---|---|---|---|---|
| MAG 1608 | 1A | narGHIJ | aniA | MtoA; MtrB2 | hoxFGHY; sdhABCD; mdh | cydA | |
| MAG 2248 | 1A | nirS | norBC | MtoA; MtrB | ackA; hoxFH; sdhABC; fumC | McHr; cydA | |
| MAG 2500 | 1A | MtoA; MtrB | hoxFGHY; sdhABC; sfcA; mdh | McHr; cydA | |||
| MAG 3581 | 1B | narGH | aniA | norC | MtoA; MtrB | hoxGHY; sdhABC; fumC; sfcA | McHr |
| MAG 4043 | 1B | napAB | nirS | norBC | MtoA; MtrB | ackA; hoxFGHY; sdhABC; mdh | McHr; cydA |
| MAG 2066 | 2A | norBC | hoxH; sdhABD; mdh | cydA | |||
| MAG 2588 | 2A | aniA | norBC | MtoA; MtrB | phbA; pta; hoxFG; sdhABCD | McHr | |
| MAG 2715 | 2A | napAB | nirS | MtoA; MtrB | ackA; sdhAB; sfcA; mdh | McHr; cydA | |
| MAG 1620 | 2B | narGHIJ | nirS; aniA | MtoA; MtrB | ackA; hoxFGH; sdhABCD; sfcA; mdh | McHr; cydA | |
| MAG 959 | 2B | narHIJ | aniA | norBC | MtoA; MtrB | pta; hoxFGHY; sdhABCD; fumC; mdh | McHr; cydA |
1) napAB = periplasmic nitrate reducatse, narGHIJ = membrane-bound nitrate reductase, nirS = cd1-type nitrite reductase, aniA = Cu-type nitrite reductases, norBC = nitric oxide reductase, MtoA = A decaheme c-type cytochrome, MtrB = decaheme-associated outer membrane protein, ackA = acetate kinase, sdhABCD = succinate dehydrogenase, sfcA = NAD(P)-dependent malic enzyme, mdh = malate dehydrogenase, phbA = 3-hydroxyacyl-CoA dehydrogenase, pta = phosphate acetyltransferase, hoxFGHY = NAD-reducing hydrogenase, fumC = fumarate hydratase class II, McHr = bacteriohemerythrin, cydA = cytochrome bd ubiquinol oxidase
2) MtoA is classified as ‘probable iron oxidation and possible iron reduction’ while MtrB is classified as ‘dissimilatory iron reduction’ or ‘probable iron reduction’ by FeGenie (Garber et al. 2020)