溶氧对地衣芽孢杆菌DW2合成杆菌肽的影响

本文研究了3L发酵罐中不同供氧水平对地衣芽孢杆菌发酵杆菌肽的影响。结果表明，地衣芽孢杆菌DW2发酵杆菌肽的总效价和A组分比例随发酵搅拌转速或通风比的提高而增加；通过比较发酵溶氧水平分别为20％和5％的杆菌肽发酵过程，初步探讨了溶氧对杆菌肽发酵的影响机制。控制发酵液溶氧20％以上，发酵液中的丙酮酸，柠檬酸和α-酮戊二酸等有机酸浓度都高于5％溶氧水平的，说明高溶氧强化了菌体EMP途径和TCA循环；分析发酵液中的Glu、Ash、His、Ile、Lys和Asp等杆菌肽组成性氨基酸浓度，都高于5％溶氧水平的，说明高溶氧还通过促进氨基酸代谢提高杆菌肽效价。

Effect of dissolved oxygen on bacitracin fermentation by Bacillus licheniformis DW2

Effect of oxygen supply on bacitracin fermentation by Bacillus licheniformis DW2 in a 3L tank was studied. The results showed that the bacitracin title and the composition ratio of A increased by speeding up the agitation and raising the aeration rate. The preliminary mechanism of dissolved oxygen on bacitracin fermentation was investigated by controling the dissolved oxygen at 20% or 5% respectively. When the dissolved oxygen maintained at 20%, the concentrations of organic acid, such as pyruvic acid and citric acid, ct - ketoglutaric acid, were higher than those under the condition of 5% dissolved oxygen, which showed that rising of dissolved oxygen could strengthen the EMP and the TCA cycle, meanwhile, the concentration of constitutive amino acids of bacitracin such as Glu, Asn, His, ile, Lys and Asp were higher than those of 5% dissolved oxygen, which showed that the high level of dissolved oxygen would improve the production of bacitracin by promoting the metabolism of amino acids.