Engineered Methylococcus capsulatus Bath for efficient methane conversion to isoprene

• Published in: Bioresource technology 2024-02, Vol.393, p.130098-130098, Article 130098
• Main Authors: Emelianov, Georgii, Song, Dong-Uk, Jang, Nulee, Ko, Minji, Kim, Seong Keun, Rha, Eugene, Shin, Jonghyeok, Kwon, Kil Koang, Kim, Haseong, Lee, Dae-Hee, Lee, Hyewon, Lee, Seung-Goo
• Format: Article
• Language: English
• Subjects: Isoprene; Methane valorization; Methanotroph; Mevalonate
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2023.130098

[Display omitted] •M. capsulatus Bath was engineered for methane-to-isoprene via MVA pathway.•Knockout mutant prevents sMMO-mediated isoprene oxidation leading to cell toxicity.•Metabolic pathway and fermentation optimization improved isoprene production.•A substantially high production of isoprene (228.6 mg/L) was achieved. Isoprene has numerous industrial applications, including rubber polymer and potential biofuel. Microbial methane-based isoprene production could be a cost-effective and environmentally benign process, owing to a reduced carbon footprint and economical utilization of methane. In this study, Methylococcus capsulatus Bath was engineered to produce isoprene from methane by introducing the exogenous mevalonate (MVA) pathway. Overexpression of MVA pathway enzymes and isoprene synthase from Populus trichocarpa under the control of a phenol-inducible promoter substantially improved isoprene production. M. capsulatus Bath was further engineered using a CRISPR-base editor to disrupt the expression of soluble methane monooxygenase (sMMO), which oxidizes isoprene to cause toxicity. Additionally, optimization of the metabolic flux in the MVA pathway and culture conditions increased isoprene production to 228.1 mg/L, the highest known titer for methanotroph-based isoprene production. The developed methanotroph could facilitate the efficient conversion of methane to isoprene, resulting in the sustainable production of value-added chemicals.