Sustainable and environmentally friendly energy production has become essential due to limited natural energy reserves and an increase in global warming. Biomethane as a renewable energy source represents a substantial opportunity to mitigate climate change by decreasing the total greenhouse gas emissions to the atmosphere when compared to fossil fuels. Anaerobic digestion of organic matter (biological decomposition without oxygen) is the major route of biomethane production with 57 EJ/year global energy potential. It can serve as one of the main energy supplies for the UK, where the primary energy consumption is ~10 EJ/year in 2013. Yet, anaerobic treatment of sulfate-containing wastewaters, such as from the brewery, pulp and paper, food processing, and tannery industries, generate very little methane. This is because, sulfate-reducing bacteria typically outcompete methane-producers for organic compounds when there is available sulfate. Evidence shows that a cooperative lifestyle may also be observed and these processes can occur simultaneously in ecosystems such as in anaerobic digesters of wastewater treatment plants. Nevertheless, the diversity and interactions (competitive or cooperative) of the key microbial groups in anaerobic digesters are largely unknown. The aim of this project is to enhance methane generation from sulfate-containing wastewaters through understanding the diversity, interactions and metabolism of anaerobic microorganisms.
We will operate laboratory-scale anaerobic reactors using sulfate-containing wastewaters (at Imperial College), and characterise the microbial diversity, function and interaction under different sulfate concentrations and carbon sources. This will be achieved via advanced molecular microbiology tools such as stable-isotope probing, high-throughput sequencing and metagenomics.