• Microbiology and Biotechnology Letters
• /
• v.22 no.5
• /
• pp.557-560
• /
• 1994

The optimum medium composition for the production of L-tryptophan with Klebsiella pnuemoniae pheA tyrA trpE trpR/pSC 101-trp$^{+}$ and the effect of precusors in the optimum medium were studied. The specific growth rate in the optimum medium was almost the same as that in the basal medium, the former showing 1.01 and the latter 1.07 hr $$^{-1}$, but the produced tryptophan was increased 45% in the optimum medium. The maximum amount of produced tryptophan was 159 mg/l within 14 hours. Tryptophan production was ceased by casamino acid addition over 4 g/l in medium, but cell maSS increased with its addition. Indole and anthranilate as precusors had toxic effect on growth and tryptophan production at experimented concentration range (over 20 mg/l), but L-serine had good effect on tryptophan production, resulting in 175 mg/l tryptophan within 14 hours.

• KSBB Journal
• /
• v.7 no.4
• /
• pp.284-289
• /
• 1992

The optimum conditions for the production of tryptophan using a recombinant Klebsiella pnuemoniae phe A tyr A trp R/pSC 101-$trp^{+}$ and its plasmid stability during tryptophan production were studied. The optimum temperature was $37^{\circ}C$ and the specific growth rate was 1.05$h^{-1}$ at $37^{\circ}C$. Tryptophan production was increased by glucose fed-batch culture, and tryptophan was accumulated to 0.175 g/l after 36 hrs. This amount was about 1.2 and 1.6 times greater than that obtained from batch culture and flask culture, respectively. The stability of the strain in fed-batch cu1ture was greatly different from that in repeated flask culture. After 6 generation, 95% of total cells was stable in repeated flash culture, but in fed-batch culture only 50% was stable.

• Korean Journal of Microbiology
• /
• v.43 no.2
• /
• pp.116-123
• /
• 2007

The purpose of this study was typing the plasmid mediated extended spectrum ${\beta}-lactamases$ produced by enteric bacteria isolated from rivers in Pusan. Six strains of Eschericha coli and fifteen strains of Klebsiella pneumoniae transferred their plasmid mediated extended spectrum ${\beta}-lactamase$ genes to the recipient strain Eschericha coli J53 $Azid^{R}$. The plasmid mediated extended spectrum ${\beta}-lactamase$ genes were sequenced directly after PCR and the types were determined by the BCM Search Launcher and GenBank nucleotid database. Determined types of the plasmid mediated extended spectrum ${\beta}-lactamases$ were TEM-52 and SHV-12. TEM-52 was isolated from both Escherichia coli and Klebsiella pneumoniae. However SHV-12 was isolated from Klebsiella pneumoniae only. The results indicated that the plasmid mediated extended spectrum ${\beta}-lactamase$ producing bacteria spreded over the area of clinical to the nature in Korea.

• Korean Journal of Microbiology
• /
• v.42 no.2
• /
• pp.125-130
• /
• 2006

The emergence of extended spectrum ${\beta}$-lactamase producing bacteria is causing very serious problems in Korea. Although there have been many reports about these bacteria Isolated from patients and clinical specimens, there is no report of extended spectrum ${\beta}$-lactamase producing organisms isolated from natural environment in Korea. This study was conducted to investigate the biological characteristics and extended spectrum ${\beta}$-lactamase types of eighteen strains of extended spectrum ${\beta}$-lactamase producing Klebsiella pneumoniae and Escherichia coli isolated from a slaughterhouse in Pusan in Korea during 2002 to 2004. Extended spectrum ${\beta}$-lactamases were identified by double-disk synergy test, conjugation, isoelectric focusing values and gene sequencing. Eight strains of Klebsiella pneumoniae and two strains of Eschericha coli were isolated kom pigs and transferred extended spectrum ${\beta}$-lactamase genes to recipient Escherichia coli J53 (sodium azide resistant and ceftazidime senstive) strain by conjugation. The conjugants of extended spectrum ${\beta}$-lactamase genes were alignments and translated to amino acids by BCM and NCBI blast. Eight conjugants of Klebsiella pneumonae were typed TEM-52, and two strains of Escherichia coli, SHV-12, but CMY-1 type were not detected in this study.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.9
• /
• pp.1586-1592
• /
• 2016

Klebsiella pneumoniae is a gram-negative, non-motile, rod-shaped, and encapsulated bacterium in the normal flora of the intestines, mouth, skin, and food, and has decarboxylation activity, which results in generation of diamines (cadaverine, agmatine, and putrescine). However, there is no specific information on the exact mechanism of decarboxylation in K. pnuemoniae. Specifically lysine decarboxylases that generate cadaverine with a wide range of applications has not been shown. Therefore, we performed a functional study of lysine decarboxylases. Enzymatic characteristics such as optimal pH, temperature, and substrates were examined by overexpressing and purifying CadA and LdcC. CadA and LdcC from K. pneumoniae had a preference for L-lysine, and an optimal reaction temperature of 37℃ and an optimal pH of 7. Although the activity of purified CadA from K. pneumoniae was lower than that of CadA from E. coli, the activity of K. pneumoniae CadA in whole cell bioconversion was comparable to that of E. coli CadA, resulting in 90% lysine conversion to cadaverine with pyridoxal 5'-phosphate L-lysine.

• The Journal of Dong Guk Oriental Medicine
• /
• v.7 no.2
• /
• pp.121-140
• /
• 1999

The various oriental herbal medicines, which have usually been used for treatment of reducing fever, purging intense heat and detoxication, were screened to determine the antibacterial activity and the minimal inhibitory concentration against pulmonary disease-causing Klebsiella pneumoniae, Streptococcus pyogenes, and Streptococcus pneumoniae. The results obtained were as follows: 1. Among the 23 oriental medicines tested, the water-soluble extracts of Coptis japonica, Scutellaria baicalensis and Picrorrhiza kurrooa showed the antibacterial activity against K.pneumoniae and that of C. japonica against S. pyogenes. The antibacterial activities of C. japonica, Prunusmume, Schizandra chinesis, Scutellaria baicalensis were also found against S.pneumoniae. When C.japonica was used, the high antibacterial activity was shown against Bacillus subtilis and other extracts showed a little activity against B. subtilis and E. coli as a control. 2. The ethanol-soluble extracts of Patrinia scabriosaefolia, P. mume, S. baicalensis, S. chinesis showed the antibacterial activity against K. pneumoniae and those of S. baicalensis, C. japonica, S. chinesis, P. mume agaist S. pyogenes and S. pnuemoniae. However, those extract showed a little antibacterial activity against B. subtilis and E. coli except for that the extract of C. japonica showed comparatively high growth inhibition of B. subtilis. 3. Among the medicinal herbs tested, the water and ethanol extrats of C. japonica showed very extcellent antibacterial activity against the pathogenic bacteria and controls. 4. When the water-soluble extracts of C. japonica and S. baicalensis, minimal inhibitory concentrations (MICs) against K. pneumoniae were $10mg/m{\ell}$ and $22 mg/m{\ell}$, respectively. The MICs of the ethanol-soluble extracts of P. mume and P. scabriosaefolia were $5mg/m{\ell}$ and $20mg/m{\ell}$, respectively. 5. For the MICs against S.pyogenes, C. japonica showed $15mg/m{\ell}$ with the water-soluble extract and P. mume and C. japonica with the ethanol-souble extract did $5mg/m{\ell}$ and $10mg/m{\ell}$, respectively. 6. For the MICs against S. pneumoniae, C. japonica and P. mume with the water- and ethanol-souble extract showed $5mg/m{\ell}$ and $10mg/m{\ell}$, respectively. As a result, the highest antibacterial activity was found in the water- and ethanol-soluble extracts of C. japonica against pulmonary disease-causing bacteria, K. pneumoniae, S. pyogenes. and S. pnuemoniae. Also, the water- and ethanol-soluble extracts of S.chinesis. P.mume, S.baicalensis, and P.kurrooa showed hight antibacterial activities.