Цепочка превращения CH4-->HCOH-->C6HnO6-->C2H5OH-->CH3COOH
CH4+02=HCOH+H2O
6HCOH+6CH2O====Ca(OH)2====C6H12O6
C6H12O6==дрожжи==2С2H5OH+2CO2 C2H5OH+2[O]=CH3COOH+H2O.