Zhou W, Holzhauer-Rieger K, Dors M, Schügerl K
Institut für Technische Chemie, Universität Hannover, F.R.G.
J Biotechnol. 1992 May;23(3):315-29. doi: 10.1016/0168-1656(92)90078-n.
Cephalosporin production by a highly productive Cephalosporium acremonium strain was carried out and optimized by fed-batch operation in a 40 l stirred tank reactor using a complex medium containing 30-120 g l-1 peanut flour. The concentrations of cephalosporin C (CPC) and its precursors: penicillin N (PEN N), deacetoxy cephalosporin C (DAOC), and deacetyl cephalosporin C (DAC) were monitored with an on-line HPLC. The concentrations of amino acids valine (VAL), cysteine (CYS), alpha-amino adipic acid (alpha-AAA), the dipeptide alpha-amino-adipyl-cysteine (AC), and the tripeptide alpha-amino-adipyl-cysteinyl-valine (ACV), were determined off-line by HPLC. The RNA content and dry weight of the sediment as well as the oxygen transfer rate (OTR) and the CO2 production rate (CPR) were used to calculate the cell mass concentration (X). The influences of peanut flour (PF) and the on-line monitored and controlled medium components: glucose (GLU), phosphate, methionine (MET) as well as the dissolved oxygen (DOC) on the cell growth, the product formation, and the pathway of cephalosporin C biosynthesis were investigated and evaluated. When the glucose fed-batch cycle was optimized and oxygen transfer limitation was avoided (DOC greater than 20% of the saturation value), high process performance (103.5 g l-1 X, 11.84 g l-1 CPC, a maximum CPC productivity of 118 mg l-1 h-1, and the whole concentration of the beta-lactam antibiotics CPC, DAC, DAOC, PEN N 17.34 g l-1) was achieved by using 100 g l-1 PF in the medium with the optimum concentration of phosphate (260-270 mg l-1) and a low glucose concentration (less than 0.5 g l-1). The cultivations with different medium concentrations demonstrated that the product formation was directly proportional to the cell mass concentration. On the average, the cell mass-based yield coefficient of CPC: YCPC/X amounted to 0.115 g CPC per g cell mass.
使用含有30 - 120 g l-1花生粉的复合培养基，在40升搅拌罐反应器中通过补料分批操作进行并优化了高产顶头孢霉菌株生产头孢菌素的过程。用在线高效液相色谱法监测头孢菌素C（CPC）及其前体：青霉素N（PEN N）、去乙酰氧基头孢菌素C（DAOC）和去乙酰头孢菌素C（DAC）的浓度。通过高效液相色谱法离线测定氨基酸缬氨酸（VAL）、半胱氨酸（CYS）、α-氨基己二酸（α-AAA）、二肽α-氨基己二酰-半胱氨酸（AC）和三肽α-氨基己二酰-半胱氨酰-缬氨酸（ACV）的浓度。利用沉淀物的RNA含量和干重以及氧传递速率（OTR）和二氧化碳产生速率（CPR）来计算细胞质量浓度（X）。研究并评估了花生粉（PF）以及在线监测和控制的培养基成分：葡萄糖（GLU）、磷酸盐、蛋氨酸（MET）以及溶解氧（DOC）对细胞生长、产物形成和头孢菌素C生物合成途径的影响。当优化葡萄糖补料分批循环并避免氧传递限制（溶解氧大于饱和度值的20%）时，通过在培养基中使用100 g l-1 PF、最佳磷酸盐浓度（260 - 270 mg l-1）和低葡萄糖浓度（小于0.5 g l-1），实现了高工艺性能（103.5 g l-1 X、11.84 g l-1 CPC、最大CPC生产率为118 mg l-1 h-1以及β-内酰胺抗生素CPC、DAC、DAOC、PEN N的总浓度为17.34 g l-1）。不同培养基浓度的培养表明，产物形成与细胞质量浓度成正比。平均而言，基于细胞质量的CPC产率系数：YCPC/X为每克细胞质量0.115克CPC。
