Effects of pulse feeding of beet molasses on recombinant benzaldehyde lyase production by Escherichia coli BL21(DE3)
Effects of pulse feeding of beet molasses on recombinant benzaldehyde lyase production by Escherichia coli BL21(DE3)
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DOI：
10.1007/s00253-009-2060-2
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发表时间：
2009-11-01
影响因子：
5
通讯作者：
Levent, Hande
中科院分区：
文献类型：
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作者：
Calik, Pinar;Levent, Hande
研究了分批补料操作（FBO）策略对重组大肠杆菌BL 21（DE 3）pLySs生产苯甲醛裂解酶（BAL）的影响。在用30 g l（-1）预处理的甜菜糖蜜（由7.5 g l（-1）葡萄糖和7.5 g l（-1）果糖组成）分批培养后，在溶解氧（=40%）级联到空气流速下应用三种FBO策略。在FBO 1中，当空气流速显著降低时，以脉冲方式向系统提供进料，使得预处理的甜菜糖蜜浓度增加10 kg m（-3）（含有2.5 g l（-1）葡萄糖+2.5 g l（-1）果糖）;然而，空气流速的降低仅证明葡萄糖而不是果糖的缺乏。因此，在FBO 2时，果糖和葡萄糖被完全利用，预处理的甜菜糖蜜脉冲进料和其浓度增加了10克升（-1）。在FBO 3中，随着预处理甜菜糖蜜量的减少，（6 g l（-1）），避免了从葡萄糖消耗到果糖消耗的转换反应时间，葡萄糖和果糖消耗与空气流速有很好的相关性，最高C（X）（8.04 g l（-1））和BAL（2，315 U ml（-1））产量（t = 24 h），细胞和产物形成的底物产率最高。
The effect of fed-batch operation (FBO) strategy was investigated using pretreated-beet molasses, containing galactose that induces the lac promoter, on benzaldehyde lyase (BAL) production by recombinant Escherichia coli BL21(DE3)pLySs. After batch cultivation with 30 g l(-1) pretreated-beet molasses consisting of 7.5 g l(-1) glucose and 7.5 g l(-1) fructose, three FBO strategies were applied at dissolved oxygen (=40%) cascade to air-flow rate. In FBO1 when air-flow rate decreased considerably, feed was given to the system in pulses in such a way that pretreated-beet molasses concentration increased by 10 kg m(-3) (containing 2.5 g l(-1) glucose+2.5 g l(-1) fructose); however, decrease in air-flow rate demonstrated only the absence of glucose but not fructose. Thus, in FBO2 when fructose and glucose were completely utilized, pretreated-beet molasses was pulse-fed and its concentration increased by 10 g l(-1). In FBO3 with the decreased amount of pretreated-beet molasses (6 g l(-1)), shift response time from glucose to fructose consumption was avoided, and glucose and fructose consumptions were well correlated with air-flow rate, and the highest C (X) (8.04 g l(-1)) and BAL (2,315 U ml(-1)) production were obtained (t = 24 h) with the highest substrate yield on cell and product formation.