2.3 Initial tolerance test of C. pasteurianum C8 to crude glycerol
To evaluate the inhibition of crude glycerol, initial tolerance test was performed in batch culture. A cyro stock culture stored in -80°C was first grown in anaerobic bottle with the pre-culture medium described above which contained 30 g/L pure glycerol. Then the culture in exponential growth phase was inoculated into the pre-culture medium containing various concentrations of crude glycerol (10, 15, 20, 25, 30, 40, 60, 80 g/L); a pre-culture medium with pure glycerol (30 or 80 g/L) was also inoculated and used as control. After anaerobic cultivation at 35°C for 12 h, OD600 of the culture was determined and compared. All tests were conducted in triplicates.