Optimization of Methanotroph Growth Conditions for Use in Industrial Applications Through Comparative Transcriptomics

Catherine Tays1,2, Lisa Stein2 and Dominic Sauvageau1.
1Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada.
2Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.

Methane, a potent greenhouse gas contributing significantly to global warming, is a common by-product of industrial activities. However, it can also serve as a useful and economical feedstock for a specialized class of bacteria known as the methanotrophs. Methanotrophs, able to consume methane as a sole energy source, have long been noted as having immense potential in the field of biotechnology, including applications in bioremediation, biotransformation, catalysis, and the synthesis of desirable biomaterials and value-added products. This project is aimed at the latter: the identification and optimization of ideal growth and bioproduction conditions in different methanotroph strains by incorporating global gene expression analysis (transcriptomics) in the development of bioprocessing strategies.

A fundamental understanding of growth behaviours is key to forming a reliable bioprocess. Therefore, optimization of methanotrophic bioproduction requires characterization of substrate-dependent growth and morphology of strains under various experimental conditions. Once growth in a number of strains under varying culturing conditions was evaluated, a global gene expression analysis was performed. Analysis of transcriptomes was aimed at identification of relevant bioproduction pathways and triggers for various growth states and highlighted differences in genomic regulation induced by the available carbon and nitrogen substrates. This approach is vital to optimizing biomass and bioproduction and achieving a cost-efficient means of production of any number of bioproducts synthesized by methanotrophs, including the storage molecule polyhydroxybutyrate (PHB), a precursor to next generation bioplastics made by many methanotroph isolates. This multi-component analysis examines both large-scale growth and molecular function, leading to an industrially applicable and reliable method of value-added product generation through the bioconversion of methane effluents. This project could result in production of biomaterials that are environmentally safe, useful for industrial application, and profitable for both bioindustry and those industries releasing methane as a by-product.