Assessment of the Effects of Methanotrophic Growth Conditions on Methane Biocatalysis for Lipid Production: An Initiative towards Climate change Mitigation

Methanotrophs are bacteria that can consume methane as their sole carbon and energy source to produce a wide variety of bio-products such as lipids. The lipids derived from methanotrophs are vital precursors for the production of green fuels and oleochemical feedstocks. Thus, this research aimed to establish the suitable growth conditions for methanotrophs consortium present in wastewater sludge that maximizes methane consumption, biomass concentration, yield coefficient and lipid content. Growth parameters were varied to study the effects of two media types [nitrate mineral salts (NMS) and synthetic wastewater (SW)], initial pH (4.0 and 6.8) and CH₄ to air ratio (1:1 and 1:4 vol.) on the bioconversion of CH₄ to lipids. After 18 days of incubation, the consortium that was cultivated in SW medium, at pH=4.0, and CH₄ to air volume ratio of 1:1 showed the highest CH₄ consumption of 43.24 ml/L which also corresponds to the highest lipid content of 459.33 mg/L. These results provide the basis of conditions for further optimization. Additionally, the findings highlight the potential of natural microbial consortium to convert methane into lipids using wastewater as medium that could address concerns on GHG emissions as well as for value-added resources recovery