• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.46-50
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• 1989

A high concentration of inorganic phosphate (above 25 mM), which was suboptimal for vegetative growth in the minimal production medium, suppressed cephalosporin C (CPC) production in Cephalosporium acremonium. Results from the determination of intracellular concentrations of ATP, ADP and AMP with phosphate-starved resting cells indicated that phosphate exerted its effect indirectly by regulating the ratio of adenylated nucleotides, the so-called adenylated energy charge. It was also found that the type of phosphate regulation of CPC biosynthesis was not a repression effect but an inhibition effect.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.221-226
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• 2000

Cephalosporin-C deacetylase (CAH) catalyzes the deacetylation of cephalosporin derivatives. A novel gene encoding the CAH from Bacillus sp. KCCM10143 was cloned and sepuenced. The uncleotide sequence contained an open reading frame encoding a polypeptide consisting of 217 amino acids and a molecular weight of 24 kDa which was in good agreement with the value obtained by sodium dodecylsulfate-polyacrylamide gel electrophoresis. An expression plasmid was constructed by inserting the CAH gene into the region of the pTrc99A expression vector. An active from of the CAH protein was expressed in the soluble fraction obtained after cell disruption. in fermentation using a 5-1 jar fementer, the transformant E. coli JM109 (pDST654) produced 4.12 U of CAH per ml of culture during 16 h of incubation.

• KSBB Journal
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• v.10 no.3
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• pp.264-270
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• 1995

Trigonopsis variabilis is a strong producer of D-amino acid oxidase that can transform cephalosporin C(ceph C) to ${\alpha}$-keto-adipyl-7-aminocephalosporanic acid(AKA-7ACA). Polymerase chain reaction (PCR) was applied to isolate the D-AAO gene from T. variabilis. To clone the PCR fragment, four different methods were examined using enzymatic reactions of Taq DNA polymerase, Klenow, T4 DNA polymerase I, Alkaline phosphatase Calf Intestinal, and T4 kinase. Ligation of phosphorylated blunt-end PCR fragment and dephosphorylated blunt-end of pUC18 plasmid yielded the best cloning efficiency One of recombinant E. coli transformants showed D-AAO activity against ceph C in both cell extracts and permeabilized cells.

• Journal of the Korean Chemical Society
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• v.38 no.7
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• pp.521-525
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• 1994

New cephalosporin antibiotics, 7-[(3,4-dihydro-6-methoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl)acetamido]-3-heterocyclothiomethyl-3-cephem-4-carboxylic acid derivatives(2a∼2d) were synthesized. Antibacterial activities of these new cephalosporin derivatives and the relationship between their structures and their activities were examined. Among them,7-[(3,4-dihydro-6-methoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl)acetamido]-3-[(2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl]-3-cephem-4-carboxylic acid exhibited the broad antibacterial activities against Gram(+) and Gram(-) bacteria.

• YAKHAK HOEJI
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• v.42 no.4
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• pp.364-369
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• 1998

New cephalosporin antibiotics. 7-[(1H-tetrazolyl)acetamidol]-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid trisodium salt 2,7-[(5-ethylthio-3-hydroxyisothiazol-4-yl)carbox-amidol-3-[(4-carboxy-3-hydroxyisothiazo1-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 3,7-[(2-aminothiazol-4-yl)acetamido]-3-[(4-carboxy-3-hydroxyisothiazol-5-yl]thiomethyl]-3-cephem-4-caboxylic acid 4,7-[(Z)-2-(2-aminothiazol-4-yl)-2-(alkoxyimino)acetamido)-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 5-9 were synthesized. Antibacterial activities of these new cephalosporin derivatives and the relationship between their structures and activities were examined. Among them, 7-((Z)-2-(2-aminothiazol-4-yl)-2-(carboxymethoxyimino)acetamido)-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 8 and 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(l-carboxy-1-methylethoxyimino)acetamido]-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 9 exhibited good antibacterial activities compared with those of cefotaxime and ceftriaxone.

• Journal of Microbiology
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• v.37 no.4
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• pp.200-205
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• 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.

• YAKHAK HOEJI
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• v.44 no.2
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• pp.155-161
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• 2000

New cephalosporin antibiotics , 3-[(4-carboxy-5-ethylthioisothiazol-3-yl)oxymethyl]-7-[(1H-tetra-zol-1-yl)acetamido]-3-cephem-4-carboxylic acid 2, 3-[(4-carboxy-5-ethylthioisothiazol-3-yl) oxymethyl]-7-[(2-aminothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid 3, 3-[(4-carb oxy-5-ethylthioisothiazol-3-yl)-oxymethyl]-7-[5-(ethylthio-3-hydroxyisothiazol-4-yl)carboxamido]-3-cephem-4-carboxylic acid 4, 3-[(4-car-boxy-5-ethylthioisothiazo1-3-yl)oxymethy1]-7-[(Z)-2-(fur-2-yl)-2-(methoxyimino)acetamido]-3-cephem-4-carboxylic acid 5, 7-[(Z)-2-(2-aminothiazol-4-yl)-2-[(alkoxyimino)acetamido]-3-[(4-carboxy-5-ethylthioisothiazol-3-yl)oxymethyl]-3-cephem-4-carboxylic acid 6-8 were synthesized. Antibacterial activities and structure-activity relationships of these new cephalosporin derivatives were examined. Among them, 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-[(4-carboxy-5-ethylthylth-ioisothiazol-3-yl)oxymethyl]-3-cephem-4-carboxylic acid 7 exhibited good antibacterial activities compared to cefotaxime and ceftriaxone.

• Archives of Pharmacal Research
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• v.15 no.3
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• pp.234-238
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• 1992

Using cell-free extract of Lysobacter lactamgenus, enzymatic conversion of $\delta$-L-($\alpha$-aminoadiphyl)-L-cysteinyl-D-valine (ACV) the first substrate of $\beta$-lactam biosynthesis, into antibiotic compounds was attempted. In high performance liquid chromatographic (HPLC) analysis, the biosynthetic intermediates for cephalosporin antibiotics including isopenicillin N, deacetoxycephalosporin C, deacetylcephalosporin C and unknown cephem compound were detected in reaction mixtures. It implies that cephabacin compounds from L lactamgenus could be produced by biosynthetic routes through penicillin ring formation and its expansion to cephalosporin ring, likely as cephalosporin C from Cephalosporium or cephamycin C from Streptomyces. Among biosynthetic enzyme in cell-free extract, the ring formation activity (isopenicillin N synthetase activity) was separated in 50-60% of ammonium sulfate fraction, and ring expansion activity (deacetoxycephalosporin C synthetase activity) was found to be in 40-50% fraction. The partially purified isopenicillin N synthetase could convert as much as 90% ACV to isopenicillin N during 6-hour reaction.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.89-92
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• 1998

The results of chromosome aberration test in mammalian cells in culture (Chinese hamster lung fibroblast cells) showed no induction of structural and numerical aberrations by YH1226, a cephalosporin antibiotic regardless of metabolic activation, while positive control group (mitomycin C and benzo(a)pyrene) showed structural chromosome aberrations of 25% and 10%, respectively. The in vivo induction of micronuclei was measured in polychromatic erythrocytes in bone marrow of male ddY mouse given YH1226 at 500, 250, 125 mg/kg by i.p. once. After 24 hours, animals were sacrificed and evaluated for the incidence of micronucleated polychromatic erythrocytes in whole erythrocytes. Although a positive response for induction of micronuclei in animals treated with mitomycin C demonstrated the sensitivity of the test system for detection of a chemical clastogen, YH1226 did not induce microunclei in bone marrow of ddY male mice.

• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.229-233
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• 1995

Acremonium chrysogenum was immobilized in ionotropic gel beads to develop semi-continuous production of cephalosporin C (CPC). Barium alginate beads were more stable than calcium alginate or strontium alginate beads in chemically defined media. The gel stability of Ba-alginate was further increased by cross-linking with polyethyleneimine (PEI). The presence of carboxymethyl cellulose inside Ba-alginate beads did not reduce mass transfer resistance. Ba-alginate microbeads that had little diffusion limitation increased CPC production rate 1.6 fold higher than that of normal beads. CPC fermentation with immobilized cells in Ba-alginate microbeads was performed continuously for 40 days by way of repeated fed-batch operations. Mathematical modeling was developed to describe the repeated fed-batch fermentation system. Results of the computer simulation agreed well with the experimental data, which made it possible to predict an optimal feeding rate that could maximize total CPC productions.