Team 3: Robert Clifford, Patricia Firmin,
Gen Liang, Rooma Raza

Methanotrophs

Wetlands
Where Do These Bacteria Live?
Sewage
Lake Basin Bogs

Methanotroph Groupings
Group I: Ribulose Monophosphate Cycle Group II: Serine Cycle
Optimize Enzyme MMO
Inhibit Enzyme MDH

Methane Monooxygenase pMMO – Particulate Methane Monoxygenase sMMO – Soluble Methane Monoxygenase

Advantages of using ammonia-oxidizing bacteria (AOB)
• Oxidize methane to methanol via the nonspecific action of the enzyme ammonia monooxygenase
• Contaminants such as moisture and CO2 do not post a limitation for biological conversion
• Can utilize the CO2 contained in gas mixtures for cell synthesis

Metabolism of AOB

Methanol Production by AOB
• Methanol production rate varies for conditions and performance
• Maximum specific productivity is 0.82 mg methanol/ mg biomass
(COD)/d

Industrial Challenges
• Microorganisms are limited.
• Inhibition on cell growth by H2S when methane in biogas is used.
• High-cost electron donors required for conversions
• Gas-Liquid Mass transfer limitations
• NH3 may inhibit the growth of microorganisms including methanotrophs

Methanotrophic strains from AD systems
Microbial electrosynthesis
Potential
Strategies
Changes in the reactor design by using Trickling biofilters for enhanced methane supply
Genetic engineering of
ANME

Outlook for Microbial Conversion

Batch and Semi-batch Production

Membrane Semi-batch Process

Methanol Production Results

References
• Fei, Q. G., Michael. Tao, Ling. Laurens, Lieve. Dowe, Nancy. Pienk, Philip T.os.
(2014). Bioconversion of natural gas to liquid fuel: Opportunities and challenges. 32(3), 596–614. doi: 10.1016/j.biotechadv.2014.03.011
• Ge, X., Yang, L., Sheets, J. P., Yu, Z., & Li, Y. (2014). Biological conversion of methane to liquid fuels: Status and opportunities. Biotechnology Advances,
32, 1460-1475. doi: http://dx.doi.org/10.1016/j.biotechadv.2014.09.004
• Pen, N. S., L. Belleville, M.-P. Sanchez, J. Charmette, C. Paolucci-Jeanjean, D.
(2014). An innovative membrane bioreactor for methane biohydroxylation.
Bioresource Technology, 174, 42–52. doi: 10.1016/j.biortech.2014.10.001
• Thorn, G. J. S. (2005). Development of an Immobilized Nitrosomonas europaea
Bioreactor for the Production of Methanol from Methane -
thesis_fulltext.pdf. Department of Chemical Process Engineering. University of Canterbury. Retrieved from http://ir.canterbury.ac.nz/bitstream/10092/1867/1/thesis_fulltext.pdf