Table 2.

Distribution of type I and type II methanotrophs isolated under various extinction-dilution enrichment series

Enrichment conditionsMethanotroph isolate affiliationc
Series letter designationNMS medium strengthaInitial pHbApprox air/CH4/CO2 headspace ratioType IType II
A0.2×4.890:9:109
C4.890:9:170
D6.890:9:130
E0.2×4.850:45:506
F0.2×6.850:45:524
G4.850:45:530
H6.850:45:520
  • a For the lower-strength enrichment series, the NMS medium (25) was diluted fivefold (0.2×).

  • b Initial pHs of some media were adjusted with concentrated phosphoric acid.

  • c Affiliation was determined by screening isolate DNA with type I and type II methanotroph-specific primer pairs.