• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.284.2-284
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• 2000

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.590-596
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• 2006

Clavulanic acid (CA) produced by Streptomyces clavuligerus is degraded during the bacterial cultivation. The degradation was examined in three different aspects, including physical, chemical, and enzymatic effects, in order to understand the degradation during the cultivation. The result showed that CA was unstable in the production medium containing ammonium salts and amino acids, owing to ammonium ions and amine groups. In addition, the degradation was not only due to instability of CA by metabolites and proteins, but also enzymes from S. clavuligerus such as $\beta-lactamase$ and penicillin-binding proteins. However, the degradation caused by these enzymes was not highly significant compared with the degradation during the cultivation, owing to irreversible reactions between CA and enzymes.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.109-112
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• 2011

A new derivative of tacrolimus was evaluated for its molecular weight, using LC-MS of the tacrolimus bulk active pharmaceutical ingredient (API) recovered through the purification of crude tacrolimus produced by Streptomyces clavuligerus CKD-1119. In addition, the molecular weight of the new derivative of tacrolimus was found to be at m/z 818 and was identified by $^{13}C$-NMR with peak assignments based on the differences in methyl group location resulting from the chemical structure. The structure of the new derivative, an unknown impurity of tacrolimus, was found to be 18-methyltacrolimus through comparison of the spectral data of the structural differences between ascomycin, tacrolimus, and the new derivative 18-methyltacrolimus.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.523-530
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• 1998

Rapid and quantitative analysis of physiological change and clavulanic acid production was studied by the combination of pyrolysis mass spectrometry (PyMS) and artificial neural network (ANN) in Streptomyces clavuligerus. Firstly, the continuous culture studies were carried out to get the physiological background and PyMS samples. Clavulanic acid production was inversely related to growth rate: Mycelium growth and $q_{cal}$ were optimum at 0.1 $h^{-1}\; and \;0.025 h^{-1}$ respectively. Changes in specific nutrient uptake rates ($q_{gly}$ and $q_{amn}$) also affected clavulanic acid production since clavulanic acid production appeared to be stimulated by the limitation of carbon and nitrogen. Fermentation broth containing mycelium taken from continuous cultures was analyzed by PyMS, and the PyMS spectra were analyzed with multivariate statistics. PCCV plots revealed that samples harvested under the same culture condition were clustered together but samples from different culture conditions formed separate clusters. To deconvolute the pyrolysis mass spectra so as to obtain quantitative information on the concentration of clavulanic acid, ANN was trained on Py MS data using a radial basis function classifier. The results showed that the physiological stages with different growth rate were successfully differentiated and it was possible to monitor the clavulanic acid production precisely and rapidly.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1689-1695
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• 2010

Pantothenate kinase (PanK) catalyzes the first step in the biosynthesis of the essential and ubiquitous cofactor coenzyme A (CoA) in all organisms. Here, we report the identification, cloning, and characterization of panK-sp from Streptomyces peucetius ATCC 27952. The gene encoded a protein of 332 amino acids with a calculated molecular mass of 36.8 kDa and high homology with PanK from S. avermitilis and S. coelicolor A3(2). To elucidate the putative function of PanK-sp, it was cloned into pET32a(+) to construct pPKSP32, and the PanK-sp was then expressed in E. coli BL21(DE3) as a His-tag fusion protein and purified by immobilized metal affinity chromatography. The enzyme assay of PanK-sp was carried out as a coupling assay. The gradual decrease in NADH concentration with time clearly indicated the phosphorylating activity of PanK-sp. Furthermore, the ca. 1.4-fold increase of DXR and the ca. 1.5-fold increase of actinorhodin by in vivo overexpression of panK-sp, constructed in pIBR25 under the control of a strong $ermE^*$ promoter, established its positive role in secondary metabolite production from S. peucetius and S. coelicolor, respectively.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.949-954
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• 2003

The argG gene of Corynebacterium glutamicum encoding argininosuccinate synthetase (EC6345) was cloned and sequenced. The gene was cloned by heterologous complementation of an Escherichia coli arginine auxotrophic mutant (argG/sup -/). The cloned DNA fragment also complements E. coli argD, argF, and argH mutants, suggesting a clustered organization of the genes in the chromosome. The coding region of the argG gene is 1,206 nucleotides long with a deduced molecular weight of about 44 kDa, comparable with the predicted size of the expressed protein on the SDS-PAGE. Computer analysis revealed that the amino acid sequence of the argG gene product had a high similarity to that of Mycobacterium tuberculosis and Streptomyces clavuligerus. Two conserved sequence motifs within the ArgG appear to be ATP-binding sites which correspond to 2 of the 3 conserved regions found in sequences of all known argininosuccinate synthetases.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.174-179
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• 1986

Augmentin is a formulation of amoxycillin trihydrate and potassium clavulanate, a fused beta-lactam molecule produced by the fermentation of Streptomyces clavuligerus. Most clinically important resistance is due to the production by bacteria of antibiotic destroying enzymes. In the case of penicillins and cephalosporins these enzymes are termed beta-lactamase as they destroy the beta-lectern ring of these antibiotics, completely inactivating them. The presence of clavulanic acid extends the spectrum of amoxycillin to include bet On clinical study of the intravenous Augmentin in the field of thoracic and cardiovascular surgical cases, we selected randomly 30 patients, 21 male and 9 female, age from 13 to 72, in the period from April to December 1985. Among the total 30 patients, 22 were preoperatively infected [11 thoracic empyema, 5 lobar pneumonia, 2 lung abscess, 2 bronchiectasis, one acute pyelonephritis with ureter stone and one rheumatic carditis], and 8 were not infected preoperatively [Table 1, 2]. Of the preoperatively infected group, 11 cases [50%] were culture positive [4 staphylococcus, 3 pseudomonas, 2 Serratia group, and one E. coli], and preoperatively non-infected group [8 cases] revealed expectedly negative findings on bacterial culture. All of the culture positive bacteria were sensitive to Augmentin on disc culture sensitivity test except one case of E. coli. Daily doses of intravenous Augmentin were 2.-1-6.0gm divided in 2-5 injections. Every injection administered [1.2gm at Augmentin dissolved in 20ml distilled water] slowly for more than 20 minutes. Duration of injection was variable according to the clinical conditions from minimum 5 to maximum 31 days. The results of antibiotic treatment with Augmentin and some other antibiotic combinations pre- and postoperatively were subgrouped as EXCELLENT, EFFECTIVE, and FAILURE. Clinical criteria of the therapeutic result were symptomatic, objective and laboratory improvement. 8 cases were excellent, 13 effective, and one failure among the preoperatively infected group, and all 8 cases of the preoperatively non-infected group were effective as pro;hylactive antibiotic therapy. Overall effective ratio was 97% in both subgroup. There was no side effect clinically and laboratory study including liver and kidney function test during and after the I.V. administration of Augmentin. Oral swallow tablets which were administered after discharge from hospital also revealed good effects with some degree of gastrointestinal trouble.