A methanol-resistant microbial strain capable of multiplying approximately 1.7 times faster in high-concentration methanol has been developed. This foundational technology is expected to accelerate the commercialization of "bio-refinery" processes, where microorganisms produce petrochemical products using methanol as feedstock.
A research team led by Professor Kim Dong-hyuk at the Department of Energy and Chemical Engineering at Ulsan National Institute of Science and Technology (UNIST) announced on January 23 that they have created a methanol-resistant strain for "C1 bio-refinery" applications using adaptive evolution technology and identified the genetic mutations in this strain.
C1 bio-refinery technology involves feeding single-carbon molecular compounds (C1) to microorganisms to produce materials such as plastic precursors that were traditionally manufactured in petroleum-based refineries. Among C1 feedstocks, methanol is particularly attractive due to its low cost and ease of transportation and storage.
The strain developed by the research team can multiply 1.68 times faster than conventional strains even in methanol concentrations as high as 2.5%. For bio-refinery technology to achieve economic viability, strains must proliferate rapidly in high-concentration methanol environments. However, typical strains experience growth inhibition when methanol concentrations exceed 1%.
The research team obtained this strain through adaptive evolution—a method that progressively increases methanol concentration levels while selecting and re-cultivating only the surviving microbes at each stage. Through this process, only "super strains" with methanol resistance remain.
By analyzing the genome of this "super strain," the team also identified evolutionary mutations. Mutations were found in genes involved in toxic byproduct synthesis (metY) and cellular energy consumption (kefB). These mutations respectively suppress the synthesis of the toxic substance methoxine and enable more efficient energy utilization.
Lead author Lee Gyu-min, a researcher, explained, "This study has secured the genetic blueprint for high-performance microorganisms for methanol-based bio-refinery processes. Using this genetic mutation information, methanol-resistant strains can be designed and produced in large quantities within a short time using tools such as gene scissors, without having to repeat the adaptive evolution process."
Professor Kim Dong-hyuk expressed expectations that "this will help lower processing costs and increase production volumes in bioplastic and organic acid production, thereby improving economic viability."
The research findings were published online on January 12 in the international academic journal "Journal of Biological Engineering."
The research was supported by the Ministry of Science and ICT's C1 Gas Refinery Project, Basic Research Laboratory Support Program, Bio-Medical Technology Development Program, and the Donggrami Foundation.