• Journal of Microbiology
• /
• 제37권4호
• /
• pp.200-205
• /
• 1999

7-Aminocephalosporanic acid (7-ACA) is the initial compound in preparation of cephalosporin antibiotics widely used in clinical treatment. Bacteria producing glutaryl 7-ACA acylase, which convert cephalosporin C to 7-ACA, has been screened in soil samples. A bacterial strain exhibiting high glutaryl 7-ACA acylase activity, designated KAC-1, was isolated and identified as a strain of Pseudomonas diminuta by characterizing its morphological and physiological properties. The screening procedures include culturing on enrichment media containing glutaric acid, glutamate, and glutaryl 7-aminocephalosporanic acid as selective carbon sources. To enhance enzyme production, optimal cultivation conditions were investigated. This strain grew optimally at pH 7 to 9 and in temperatures of 20 to 40 C, but acylase production was higher when the strain was grown at 25 C. Glutaric acid, glutamate and glucos also acted as inducers for acylase production. In a jar fermenter culture, P. diminuta KAC-1 produce acylase in a growth-associated manner. The substrate specificity of KAC-1 acylase by cell extract showed that this enzyme had specificity toward glutaryl 7-ACA, glutaryl 7-ADCA, but not cephalosporin C.

• Journal of Microbiology and Biotechnology
• /
• 제11권3호
• /
• pp.452-457
• /
• 2001

The glutaryl 7-aminocephalosporanic acid (glutaryl 7-ACA) acylase was purified from Pseudomonas diminuta KAC-1 cells isolated from soil, and characterized. The acylase was purified by procedures including ammonium sulfate fractionation and column chromatographies on DEAE-Sepharose, Phenyl-Sepharose, Q-Sepharose, and Superose 12H/R. The negative acylase was found to be composed of two subunits with molecular masses of approximately 55 kDa and 17 kDa, respectively. The isoelectric point of the enzyme was 4.0. The specific activities of the purified acylase were 8.0 and 7.0 U/mg on glutaryl 7-ACA and glutaryl 7-aminodesacetoxy cephalosporanic acid (glutaryl 7-ADCA), respectively, and $K_m$ values were 0.45 mM for glutaryl 7-ADCA and 0.67 mM for glutaryl 7-ADCA. The enzyme had a pH optimum at 8.0 and a tmperature optimum at $40^{\circ}C$. The acylase catalyzed the synthesis of glutaryl 7-ACA from glutaric acid and 7-ACA as well as the hydrolysis of glutaryl 7-ADCA, although the reaction rate of the synthesis was slower than that of the hydrolysis. In addition, it was found that the enzyme had a glutaryl transferase activity, thereby transferring the glutaryl group from one cephalosporin nucleus to another.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제10권6호
• /
• pp.510-515
• /
• 2005

Pseudomonas cepacia BY21 was found to produce glutaryl acylase that is capable of deacylating glutaryl-7-aminocephalosporanic acid (glutaryl-7-ACA) to 7-aminocephalosporanic acid (7-ACA), which is a starting material for semi-synthetic cephalosporin antibiotics. Amino acids of the reported glutaryl acylases from various Pseudomonas sp. strains show a high similarity (>93% identity). Thus, with the known nucleotide sequences of Pseudomonas glutaryl acylases in GenBank, PCR primers were designed to clone a glutaryl acylase gene from P. cepacia BY21. The unknown -subunit gene of glutaryl acylase from chromosomal DNA of P. cepacia BY21 was cloned successfully by PCR. The -subunit amino acids of P. cepacia BY21 acylase (GenBank accession number AY948547) were similar to those of Pseudomonas diminuta KAC-1 acylase except that Asn408 of P. diuminuta KAC-1 acylase was changed to Leu408.