Interactive effect of Cu2+/Fe2+ ratio on methane oxidation and PHA (PHB) accumulation in methanotrophic consortia

In this study, two different methanotrophic consortia were established form landfill topcover (landfill biomass [LB]) and compost soils (compost biomass [CB]), through cultivation under CH4:CO2:air (30:10:60) in batch systems. The established cultures were then used as inoculi in continuous stirred tank reactors(CSTRs) aerated with CH4:CO2:air at 0.25 L/min-1. Under stable CSTRs operating conditions, the effect of spiking with 1:1 copper:iron at day 5, 1:10 at day 10 and 1:15 at day 15 was tested. Methane oxidation capacity (MOC), biomass dry weight (DWbiomass), PHB, and fatty acid methyl esters (FAMEs) contents were used as effect parameters. Change in the methanotrophic community composition, with respect to copper and ion ratios was characterised using 16srDNA sequencing.