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首页> 外文期刊>Bioprocess and Biosystems Engineering >Enzymatic synthesis of cefazolin using immobilized recombinant cephalosporin-acid synthetase as the biocatalyst
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Enzymatic synthesis of cefazolin using immobilized recombinant cephalosporin-acid synthetase as the biocatalyst

机译：固定化重组头孢菌酸合成酶催化生物合成头孢唑啉

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摘要

A method for the synthesis of -lactam antibiotic cefazolin (CEZ) by enzymatic acylation of 7-amino-3-(5-methyl-l,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (TDA) using immobilized cephalosporin-acid synthetase (IECASA) from recombinant E. coli strain VKPM B-12316 has been developed. A stepwise pH gradient designed on the basis of investigations on the solubility of components was applied for synthesis. This helped in avoiding the precipitation of TDA in the reaction when its initial concentration was high (150-200mM). Thus, under optimal conditions a high yield of CEZ (relative to TDA) of 92-95% was obtained. Where the final reaction mixture contained 65-85mg/mL of CEZ, 4-5mg/mL of unreacted TDA, and 40-60mg/mL of the by-product, 1(H)-tetrazolylacetic acid (TzAA). Testing of optimized CEZ synthesis using IECASA in a batch reactor has proved sufficiently high operational stability of the biocatalyst, with its residual activity after the 25th cycle accounting for about 83 +/- 2% of its starting value. The half-inactivation period of IECASA was estimated as 85 cycles of CEZ synthesis.
机译：通过氨基7-氨基-3-（5-甲基-1,3,4-噻二唑-2-基）硫甲基-3-cephem-4-羧酸的酰化反应合成-内酰胺抗生素头孢唑啉的方法已经开发了使用来自重组大肠杆菌菌株VKPM B-12316的固定化头孢菌素酸合成酶（IECASA）的DNA（TDA）。基于对组分溶解度的研究而设计的逐步pH梯度用于合成。当其初始浓度较高（150-200mM）时，这有助于避免TDA在反应中沉淀。因此，在最佳条件下，可获得92-95％的高CEZ产量（相对于TDA）。最终反应混合物中含有65-85mg / mL的CEZ，4-5mg / mL的未反应TDA和40-60mg / mL的副产物1（H）-四唑基乙酸（TzAA）。在间歇反应器中使用IECASA对优化的CEZ合成进行的测试证明，该生物催化剂具有足够高的运行稳定性，在第25个循环后其残留活性约占其起始值的83 +/- 2％。 IECASA的半灭活期估计为CEZ合成的85个循环。

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