2.3 Whole-cell catalysis
The G. oxydans catalyzed bioprocess for primary diols was
conducted in a 250-mL Erlenmeyer flask containing 0.5 g/L
MgSO4, 1 g/L KH2PO4, 2
g/L K2HPO4, 5 g/L
(NH4)2SO4 and 5 g/L yeast extract. The
previously washed spare cells were measured at a wavelength of 600 nm by
ultraviolet spectrophotometry(Yao et al., 2017). Then, the cells with
OD600 = 2 concentration were centrifuged and inoculated
into the catalytic medium containing primary diols. The whole course was
performed at a constant temperature of 30 ℃, with continual agitation at
220 rpm using a shaking table. Moreover, the ultra-high titer 5-HPA was
conducted in a sealed oxygen supplied bioreactor (SOS-BR) in which pure
oxygen (Purity≥99.9%) was fed into the bioreactor with an oxygen
cylinder replacing the air compressor and the pressure of the bioreactor
was controlled at 0.03-0.05 MPa by an exhaust valve(Hua et al., 2020).