초록
The impact of anaerobiosis strategy on 1,3-propanediol production during cultivation of Clostridium butyricum VPI 1718 in different size bioreactors was studied. In batch trials with N<SUB>2</SUB> gas infusion, the fermentation was successfully accomplished, regardless of initial glycerol concentration imposed and bioreactor geometry. However, in the absence of N<SUB>2</SUB> continual sparging, significant variations concerning the biochemical response of the strain were observed. Specifically, at 1-L bioreactor, the absence of N<SUB>2</SUB> infusion at high initial glycerol concentration induced lactate dehydrogenase activity and thus lactic acid synthesis, probably due to partial blockage of phosphoroclastic reaction caused by insufficient self-generated anaerobiosis environment. During fed-batch cultivation with continual N<SUB>2</SUB> sparging, the strain produced ~71gL<SUP>-1</SUP> of 1,3-propanediol, whereas under self-generated anaerobiosis, 1,3-propanediol pathway was evidently restricted, as only 30.5gL<SUP>-1</SUP> of 1,3-propanediol were finally produced. Apparently, N<SUB>2</SUB> infusion strategy paired with bioreactor geometry can alter the biochemical behavior of the particular strain.