Several strains of methane-oxidizing bacteria were isolated and studied to determine their physiological suitability for removal of methane in coal mine atmospheres. One strain, Methylomonasfodinarum ACM 3268, was selected as the most suitable culture for use in the development of a continuous biofilter to be used as a ventilation "air scrubber". The experimental biofilter utilising a biofilm of M. fodinarum was shown to reduce methane levels substantially provided the residence times were sufficiently long. In the range 0.25-1.0%0 methane in air, commonly experienced in coal mine atmospheres, more than 70% of the methane was removed with a residence time of 15 min, with a 90% reduction at 20 min. Even at a residence time of 5 min approximately 20% of the methane in air was removed. Equal quantities of 02 are consumed during the bacterial oxidation of methane and 1% methane is converted to 0.7% CO2. Scale-up and alternative biofilter packings are likely to reduce the residence times in the biofilter.

The detection of acidophilic microorganisms from mining environments by culture methods is time consuming and unreliable. Several PCR approaches were developed to amplify small-subunit rRNA sequences from the DNA of six bacterial phylotypes associated with acidic mining environments, permitting the detection of the target DNA at concentrations as low as 10 fg.