2.2 Tolerance and degradation test in E. coli
All tolerance and degradation were studied for E. coli Bgl4146 at 37°C with 200 rpm. The seed solution was inoculated into Lysogeny broth (LB) and cultured overnight at 37°C. Then the seeds were inoculated (2% working volume) into 50 mL M9 minimal medium supplemented with 5 g/L glutarate as the only carbon source for glutarate degradation or different concentrations of acetate(0 g/L, 3 g/L, 6 g/L, 9 g/L, 12 g/L) as the single carbon source for acetate degradation. The glutarate tolerance test was performed in an optimized super optimal broth (SOB)( Zhao, Li, & Deng, 2018), which was also used in glutarate production by the engineered strains as described below. Briefly, SOB medium with different final concentrations (0, 5, 10, 15, 20, 30, 40, 50, 100, or 150 g/L glutarate and adjusted to pH 7.00) were inoculated and initial OD600 remained around 0.3.