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研究论文

Control module for dissolved oxygen in a novel bioflocculant production from Corynebacterium glutamicum

摘要：在3L发酵罐上系统研究溶氧水平对谷氨酸棒杆菌菌体生长及新型生物絮凝剂REA 11合成的影响,提出生物絮凝剂REA 11合成的分阶段供氧控制策略:发酵过程0～16h维持体积传氧系数kLa为100h^-1,16h后降低kLa为40h^-1至发酵结束,整个发酵过程通气量保持在1L·L^-1·min^-1.采用该分阶段供氧控制策略,生物絮凝剂最终产量达到900mg·L^-1,发酵周期缩短到30h,比恒定kLa为40h^-1条件下的REA-11产量(549mg·L^-1)提高了64%,产率提高了45%,生产强度也比kLa恒定为40h^-1,100h^-1和200h^-1的分批发酵过程分别提高了81.2%,120%和420%,实现了高细胞生长速率和高产物产率的统一.

Abstract：The effect of dissolved oxygen tension （DOT） on cell growth and flocculant production by Corynebacterium glutamicum CCTCC M201005 was systematically investigated in an automatic 3-litre fermentor. A stepwise oxygen supply strategy was employed to maintain the oxygen-transfer coefficient （k_La） to be 100h^-1 in the first 16 hours of the fermentation, then to decrease k_La to be 40h^-1 till the end of fermentation, while the aeration rate was maintained to be 1L·L^-1·min^-1 during the entire fermentation process. With this strategy the yield of REA-11 was greatly improved especially in the late period of fermentation. The ultimate flocculant yield reached 900mg·L^-1, improved by 63.9%; Y_p/s improved by 45% and the fermentation time was shortened to 30 hours compared with those from the fermentation mode with constant k_La (40h^-1). The productivity was also improved by 81.2%, 120% and 420% compared with those from fermentations with different constant k_La set at 40h^-1,100h^-1 and 200h^-1, respectively. High cell growth rate and high bioflocculant production were thus simultaneously obtained with this stepwise oxygen supply strategy.