2.2 Microorganism
G. oxydans NL71 was derived from ATCC621. The strain was
preserved in sorbitol-agar medium containing 50 g/L sorbitol, 5 g/L
yeast extract and 15 g/L agar, at 4 ℃. The inoculum was cultivated in a
baffled Erlenmeyer flask at 30 ℃ for 24-36 h, with continual agitation
at 220 rpm using a shaking table (New Brunswick Scientific). The
nutrient medium was composed of 100 g/L sorbitol and 10 g/L yeast
extract. The cultured cells were centrifuged at 6000 rpm and 4 ℃, for
5-10 min by freezing centrifuge (Avanti J-26 XP, Beckman Coulter). The
centrifuged cells were washed 3 times in sterile saline and sterile
water for reserve, respectively(Zhou et al., 2018).