Bio-isopropanol production in Corynebacterium glutamicum: Metabolic redesign of synthetic bypasses and two-stage fermentation with gas stripping

• DOI: 10.1016/j.biortech.2022.127171
• Publication Date: 2022-04-25T08:54:24Z
• Authors: Young Jin Ko; Joy Cha; Wu-Young Jeong; Myeong-Eun Lee; Byeong-Hyeon Cho; Bhardwaj Nisha; Hyun Jin Jeong; Sung Eun Park; Sung Ok Han
• Keywords: 2-Propanol; Corynebacterium glutamicum; 0301 basic medicine; 03 medical and health sciences; Metabolic Engineering; Fermentation; Succinic Acid

Isopropanol is a commodity chemical widely used as a biofuel, fuel additive, rubbing alcohol and intermediate in various fields. Here, an engineered Corynebacterium glutamicum overproducing isopropanol was developed. To our knowledge, despite a representative industrial host to produce valuable chemicals, the high-level production of isopropanol in C. glutamicum has never been reported. First, the problem of the inability to produce isopropanol was solved by finding a key factor in its metabolism. The consolidation and modular optimization of synthetic bypasses including succinate and mevalonate bypasses enhanced isopropanol production. Flux redistribution of central metabolism significantly directed the carbon flux toward isopropanol biosynthesis. The final engineered strain produced 10.25 ± 1.12 g/L isopropanol in two-stage fed-batch fermentation with an optimized gas stripping, which is the highest titer, yield and productivity in C. glutamicum. These strategies could be useful for the high-level production of isopropanol in C. glutamicum.