• Archives of Pharmacal Research
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• v.15 no.4
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• pp.360-364
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• 1992

Methylcatechol 2, 3-dioxygenase encoded in pWWO megaplasmid of Pseudomonas putida mt-2 has been cloned and overexpressed in Escherichia coli. This enzyme gene has been localized inside 2. 3-kb XhoI fragment derived from the pWWO megaplasmid. Analysis of enzyme activity and SDS-PAGE showed that the cloned methylcatechol 2, 3-dioxygenase gene in E. coli was about 100 fold overexpressed compared with the parental gene in P. putida mt-2 (pWWO). The cloned enzyme exhibited higher ring-fission activity to catechol than catechol derivatives including 3-methylcatechol, 4-methylcatechol, and 4-chlorocatechol.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.2
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• pp.119-124
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• 2015

Pyoverdines (PVDs) are organic compounds produced by the fluorescent Pseudomonads under iron starvation conditions. Among the isolated rhizosphere pseudomonads strains, P. putida KNUK9 showed the highest production of PVDs and its production reached to 62.81% siderophores units. DNA isolation, ligation, PCR amplification, and transformation using E. coli $DH5{\alpha}$ cells were carried out for preparing the strong pyoverdine producer strains. We detected seven genes playing the fundamental roles in the pyoverdine metabolism in Pseudomonads. According to data and analysis obtained from the study, we deduced that the strain P. putida KNUK9 contains the essential genes required for pyoverdine biosynthesis.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.10-19
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• 1997

Fusarium wilt of radish (Raphanus sativus L.) is caused by the Fusarium oxysporum f. sp. raphani (FOR) which mainly attacks Raphanus spp. The pathogen is a soil-borne and forms chlamydospores in infected plant residues in soil. Infected pathogen colonizes the vascular tissue, leading to necrosis of the vascular tissue. Growth promoting beneficial organisms such as Pseudomonas fluorescens WCS374 (strain WCS374), P. putida RE10 (strain RE10) and Pseudomonas sp. EN415 (strain EN415) were used for microorganisms-mediated induction of systemic resistance in radish against Fusarium wilt. In this bioassy, the pathogens and bacteria were treated into soil separately or concurrently, and mixed the bacteria with the different level of combination. Significant suppression of the disease by bacterial treatments was generally observed in pot bioassy. The disease incidence of the control recorded 46.5% in the internal observation and 21.1% in the external observation, respectively. The disease incidence of P. putida RE10 recorded 12.2% in the internal observation and 7.8% in the external observation, respectively. However, the disease incidence of P. fluorescens WCS374 which was proved to be highly suppressive to Fusarium wilt indicated 45.6% in the internal observation and 27.8% in the external observation, respectively. The disease incidence of P. putida RE10 mixed with P. fluorescens WCS374 or Pseudomonas sp. EN415 was in the range of 10.0-22.1%. On the other hand, the disease incidence of P. putida RE10 mixed with Pseudomonas sp. EN415 was in the range of 7.8-20.2%. The colonization by FOR was observed in the range of $2.4-5.1{\times}10^3/g$ on the root surface and $0.7-1.3{\times}10^3/g$ in the soil, but the numbers were not statistically different. As compared with $3.8{\times}10^3/g$ root of the control, the colonization of infested ROR indicated $2.9{\times}10^3/g$ root in separate treatments of P. putida RE10, and less than $3.8{\times}10^3/g$ root of the control. Also, the colonization of FOR recorded $5.1{\times}10^3/g$ root in mixed treatments of 3 bacterial strains such as P. putida RE10, P. fluorescens WCS374 and Pseudomonas sp. EN415. The colonization of FOR in soil was less than that of FOR in root part. Based on soil or root part, the colonization of ROR didn't indicate a significant difference. The colonization of introduced 3 fluorescent pseudomonads was observed in the range of $2.3-4.0{\times}10^7/g$ in the root surface and $0.9-1.8{\times}10^7/g$ in soil, but the bacterial densities were significantly different. When growth promoting organisms were introduced into the soil, the population of Pseudomonas sp. in the root part treated with P. putida RE10 was similar in number to the control and recorded the low numerical value as compared with any other treatments. The population density of Pseudomonas sp. in the treatment of P. putida RE10 indicated significant differences in the root part, but didn't show significant differences in soil. The population densities of infested FOR and introduced bacteria on the root were high in contrast to those of soil. P. putida RE10 and Pseudomonas sp. EN415 used in this experiment appeared to induce the resistance of the host against Fusarium wilt.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.6
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• pp.389-393
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• 2013

The purpose of this study is to investigate the biodegradation characteristics of the xylene by BTEX-degrading bacteria, Pseudomonas putida BJ10, isolated from oil-contaminated soil and bio-degradation pathway of the xylene. The removal efficiencies of o, m, p-xylene in mineral salts medium (MSM) by P. putida BJ10 were 94, 90 and 98%, respectively for 24 hours. It shows clear difference compared with the control groups which were below 3%. The removal efficiencies of BTEX by P. putida BJ10 in gasoline-contaminated soil were 66% for 9 days. They were clearly distinguished from the control groups (control and sterilized soil) which were 32 and 8%. 3-methylcatechol and o-toluic acid were detected after 6 and 24 hours during the o-xylene biodegradation pathway. Therefore, we confirmed o-toluic acid as the final metabolite. And intermediate-products were somewhat different with previously published studies of the transformation pathway from o-xylene to 3-methylcatechol.

• Journal of Microbiology
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• v.44 no.5
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• pp.473-479
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• 2006

A well characterized naphthalene-degrading strain, Pseudomonas putida PpG7 was observed to utilize limonin, a highly-oxygenated triterpenoid compound as a sole source of carbon and energy. Limonin concentrations evidenced a 64% reduction over 48 h of growth in batch cultures. Attempts were made to acquire a plasmid-less derivative via various methods (viz. Ethidium Bromide, SDS, elevated temperature & mitomycin C), among which the method involving mitomycin C ($20{\mu}g/ml$) proved successful. Concomitant with the loss of plasmid in P. putida PpG7 strain, the cured derivative was identified as a $lim^-$ phenotype. The $lim^+$ phenotype could be conjugally transferred to the cured derivative. Based on the results of curing with mitomycin C, conjugation studies and presence of ndo gene encoding naphthalene 1,2 dioxygenase, it was demonstrated that genes for the limonin utilization were encoded on an 83 kb indigenous transmissible Inc. P9 NAH plasmid in Pseudomonas putida PpG7 strain.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1214-1220
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• 2005

Decreased porin-mediated outer membrane penetration of hydrophilic antibiotics is a common mechanism of antibiotic resistance in Gram-negative bacteria. This study was undertaken to determine whether a null mutation in Pseudomonas putida would suppress porin synthesis, and therefore reduce the susceptibility of the organism to streptomycin, norfloxacin, and tetracycline. Inverse PCR amplification and double-stranded DNA sequencing were used to identify chromosomal genes carrying TnphoA'-1 inserts. Genome database available was used to identify putative homologue genes, one of which encodes protein with homology to domains of the MutS of P. putida, suggesting a crucial role in the multidrug resistance. Increased resistance to streptomycin, norfloxacin, and tetracycline might be due to accumulation of compensatory mutations. Either no growth or slow growth was observed in P. putida KH1027 when grown in minimal medium containing gluconate, glucose, or citrate; however, it is not clear whether the growth patterns contributed to the multidrug resistance.

• Microbiology and Biotechnology Letters
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• v.16 no.3
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• pp.199-204
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• 1988

A strain capable of growth on naphthalene minimal medium was isolated from soil by selective enrichment culture and identified as Pseudomonas putida N3 according to its morphological and physiological characteristics. The optimum pH and temperature for growth of the isolate were 7.0 and 3$0^{\circ}C$, respectively. This strain was resistant to ampicillin, chloramphenicol, kanamycin and streptomycin but. sensitive to tetracycline and rifampicin. Of the naphthalene related compounds, 1, 5-dihydroxynaphthalene was more easily utilized than naphthalene due to its solubility. And catechol was degraded through meta-cleavage pathway. A 110 Kb plasmid which encodes for a single set of enzymes responsible for the degradation of naphthalene was obtained.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.859-862
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• 2004

An isolate of Pseudomonas putida has been found to aggressively colonize root tips and induce plant resistance to Fusarium wilt. However, P. putida mutants lacking Fe-superoxide dismutase (SOD) or both FeSOD and MnSOD activities are less competitive in root tip colonization. In the current study, the growth of an FeSOD mutant was found to be more sensitive than that of the wild-type or a MnSOD mutant to oxidative stress imposed by paraquat treatment and culturing with the soil fungus Talaromyces flavus, which generates reactive oxygen species. Also, the loss of culturability with an aging stationary-phase culture was greater for a double SOD mutant than an FeSOD mutant, while no reduction in culturability was observed with the wild-type and a MnSOD mutant under the same protracted stationary-phase conditions. Accordingly, it was concluded that FeSOD activity is the major form of SOD in P. putida and plays an essential role in survival under stress conditions when increased oxidative stress is encountered.

• Korean Journal of Microbiology
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• v.25 no.3
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• pp.198-204
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• 1987

Biparental clones and recombinant clones were obtained by spheroplast fusion of Pseudomonas putida KU218R-3 and P.putida KU428. Formation of the fusion product was the most effective when the Pseudomonas spheroplast mixture were treated with 40% plyethyleneglycol(PEG) 6000 for 10min at room temperature, The fusants which selected by indirect method were obtained at an average frequency of 10.8%. Most of the fusants were biparental clones (10.4%) and the recombinant clones were produced in low yield (0.42%). Fusants, at the frequency of 4% were obtained without PEG 6000, which shows that fusion is not strictly dependant on PEG. The stability of fusants were examined. Most of the biparental clones were segregated to parental form amd late recombinants were formed on further propagation of biparental clone but the recombinant clones were nery stable.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.282-289
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• 1987

The characteristics of the plasmid pKU10 isolated from Pseudomonas putida KU816 were investigated and its restriction map was constructed. The pKU10 plasmid was a small R plasmid carrying genes for resistance to ampicillin, tetracyclin, and chloramphenicol, and cured by treatment with mitomycin C. The molecular size of pKU10 was estimated to be 9.4Kb. Pseudomonas strains and E. coli cells could be transformed for antibiotic resistance characters specified by pKU10 plasmid DNA. By incompatibility test with other plasmids, pKU10 is grouped into IncP-1. EcoRI, XhoI, SalI, BglII, and SmaI cleaved pKU10 once, while PstI cleaved at two sites, and HindIII cleaved at six sites. The restriction map was constructed by partial and complete digestion of the purified plasmid DNA with single, double, or triple restriction enzymes. Thus, pKU10 is expected to be used for a cloning vector in Pseudomonas cells.