Acidophilic methanotrophs: Occurrence, diversity, and possible bioremediation applications

Methanotrophs have been identified and isolated from acidic environments such as wetlands, acidic soils, peat bogs, and groundwater aquifers. Due to their methane (CH4) utilization as a carbon and energy source, acidophilic methanotrophs are important in controlling the release of atmospheric CH4, an important greenhouse gas, from acidic wetlands and other environments. Methanotrophs have also played an important role in the biodegradation and bioremediation of a variety of pollutants including chlorinated volatile organic compounds (CVOCs) using CH4 monooxygenases via a process known as cometabolism. Under neutral pH conditions, anaerobic bioremediation via carbon source addition is a commonly used and highly effective approach to treat CVOCs in groundwater. However, complete dechlorination of CVOCs is typically inhibited at low pH. Acidophilic methanotrophs have recently been observed to degrade a range of CVOCs at pH < 5.5, suggesting that cometabolic treatment may be an option for CVOCs and other contaminants in acidic aquifers. This paper provides an overview of the occurrence, diversity, and physiological activities of methanotrophs in acidic environments and highlights the potential application of these organisms for enhancing contaminant biodegradation and bioremediation.

Automated summary

Methanotrophs found in acidic environments play a vital role in controlling the release of atmospheric methane and in the biodegradation and bioremediation of pollutants. They utilize methane as a carbon and energy source and can degrade chlorinated volatile organic compounds under low pH conditions. This paper provides an overview of the occurrence, diversity, and physiological activities of these methanotrophs, highlighting their potential applications in contaminant biodegradation and bioremediation.