Microbial conversion of methane to value-added chemicals is a potential technology for reducing dependence on petroleum-based products in an environmentally friendly manner. However, the poor mass transfer rate of sparingly soluble methane is a major barrier in the successful design and operation of such a process at large-scale.

This sub-project will develop a novel methane fermentation system using gas permeable membranes that will significantly improve the methane transfer rate to microorganisms. We will address a number of issues limiting mass transfer rate and efficiency by optimising methane partial pressure, surface area to volume ratio and recirculation rate.

Recently, we developed a membrane biofilm reactor (MBfR) that can produce volatile fatty acids (VFAs) from methane fermentation under oxygen-limiting conditions. However, the pathway and the key microorganisms involved in methane conversion are still not clear.

This sub-project will develop MBfR technology for high-rate cultivation of methanotrophs for multiple applications, including VFA/solvent production, single cell protein production, and bioremediation of oxidized contaminants such as selenate and perchlorate in groundwater.

Funding

  • FL170100086

Project Outcomes

The key purpose of this project is to:

  1. Identify key microorganisms and metabolic pathways for conversion of methane to liquid chemicals under micro-aerobic conditions
  2. Determine roles of oxygen/nitrate/methane/CO2 in VFA production
  3. Develop biotechnology for methane fermentation, specifically a hybrid MBfR reactor to enable efficient gas transfer
  4. Develop applications of methane-based biotechnology
    • Bioremediation of nitrate, nitrite, perchlorate, and selenate from contaminated water
    • Single-cell protein production

Publications

1. Chen, H.; Zhao, L.; Hu, S.; Yuan, Z.; Guo, J., 2018. High-rate production of short-chain fatty acids from methane in a mixed-culture membrane biofilm reactor. Environmental Science & Technology Letters, 5, 662-667.

2. Chen, H.; Luo, J.; Liu, S.; Yuan, Z.; Guo, J., 2019. Microbial methane conversion to short-chain fatty acids using various electron acceptors in membrane biofilm reactors. Environmental science & technology, 53, 12846-12855.

4. Wu M.; Luo J.; Hu S.; Yuan Z.; Guo J., 2019. Perchlorate bio-reduction in a methane-based membrane biofilm reactor in the presence and absence of oxygen. Water Research, 157, 572-578.

3. Chen, H.; Liu, S.; Liu, T.; Yuan, Z.; Guo, J., 2020. Efficient nitrate removal from synthetic groundwater via in situ utilization of short-chain fatty acids from methane bioconversion. Chemical Engineering Journal, 393, 124594.

5. Wang Y.; Lai C.; Wu M.; Song Y.; Hu, S.; Yuan, Z.; Guo, J., 2021. Roles of oxygen in methane-dependent selenate reduction in a membrane biofilm reactor: stimulation or suppression. Water Research, 198, 117150.

6. Zhao L.; Chen H.; Yuan Z.; Guo J., 2021. Interactions of functional microorganisms and their contributions to methane bioconversion to short-chain fatty acids. Water Research, 199, 117184.

7. Wang Y.; Lai C.; Wu M.; Lu X.; Hu, S.; Yuan, Z.; Guo, J., 2022. Copper stimulation on methane-supported perchlorate reduction in a membrane biofilm reactor. Journal of Hazardous Materials, 425, 127917.

Project members

Associate Professor Jianhua Guo

UQ Amplify Fellow
Australian Centre for Water and Environmental Biotechnology

Dr Mengxiong Wu

Postdoctoral Research Fellow
Australian Centre for Water and Environmental Biotechnology

Professor Zhiguo Yuan

Centre Dir & ARC Laureate Fellow
Australian Centre for Water and Environmental Biotechnology

Other members

  • Dr Lei Zhao