• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.4
• /
• pp.636-641
• /
• 1995

Proteolytic activities were compared using three species involving in squid jeotkal fermentation and showing positive reaction upon casein test : Pseudomonas D2, Flavovacterium odoratum and Acinetobacter calcoaceticus. Pseudomonas D2 produced highest activity of protease at 72h when incubated in our own modified medium(polypeptone, 0.5% ; tryptone, 0.5% ; NaCl, 3% ; pH, 7.5). Thus, this specie was selected for the further study. The growth pattern was coincided with the production of protease. Thus purification of protease was proceeded by ethanol precipitation, sephadex G-100 gel filtration, and DEAE sepharose ion exchange chromatography. The purified protease showed highest activity at pH 7.0 and 5$0^{\circ}C$. The enzyme was very stable over the wide ragnes of the temperature ; even with one hour heat treatment at 7$0^{\circ}C$, the enzyme showed substantial amount of the activity toward casein. In addition, the enzyme was stable over the wide range of pH. Molecular weight of the protease was determined to be 17.4 kD by SDS-PAGE.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.3
• /
• pp.371-376
• /
• 2002

A biosurfactant-producing bacterial strain was selected from diesel-contaminated soil by measuring the oil-film collapsing activity and identified as Pseudomonas aeruginosa D2D2. When glucose and olive oil were used as carbon sources, 11.46 g/1 of biosurfactant was obtained. Based on TLC analysis, the biosurfactant produced from P. aeruginosa D2D2 was identified as a glycolipid, consisting of two types of biosurfactants (Type I and Type II). The purified glycolipid reduced the surface tension of the culture from 72 dyne/cm to 27 dyne/cm. The hydrophilic and hydrophobic moiety of the biosurfactant were rhamnose and ${\beta}$-hydroxydecanoic acid, as determined by FAB-MS and NMR analyses, respectively.

• Journal of Microbiology and Biotechnology
• /
• v.10 no.2
• /
• pp.258-263
• /
• 2000

2-Hydroxy-6-oxo-6phenylhexa-2,4-dienoate (HOPDA) hydrolase catalyzes the hydrolytic cleavage of HOPDA to bemzpate and 2-hydroxypenta-2, 4-dienoate (HPD) during microbial catabolism of biphenyl and polychlorinated biphenyls. A HOPDA hydrolase gene (pcbD) was isolated from the genomic library of Pseudomonas sp. P20 and designated as pCNUO1201; a 7.5-kb XbaI DNA fragment from Pseudomonas sp. P20 was inserted into the pBluescript SK(+) XbaI site. E. coli HB101 harboring pCNU1201 exhibited HOPDA hydrolase activity. The open reading frame (ORF) corresponding to the pcbD gene consisted of 855 base pairs with an ATG initiation codon and a TGA termination codon. The ORF was preceded by a rebosome-binding sequence of 5'-TGGAGC-3' and its G+C content was 55 mol%. The pcbD gene of Pseudomonas sp. P20 was located immedeately downstream of the pcbC gene encoding 2,3- dihydroxybiphenyl 1,2-dioxygenase, and approximately 4-kb upstream of the pcbE gene encoding HPD hydratase. The pcbK gene was able to encode a polypeptide with a molecular weight of 31,732 containing 284 amino acid residues. The deduced amino acid sequence of the HOPDA hydrolase of Pseudomonas sp. P20 exhibited high identity (62%) with those of the HOPDA hydrolases of P. putida KF715, P. pseudoalcaligenes KF707, and Burkholderia cepacia LB400, and also significant homology with those of other hydrolytic enzymes including esterase, transferase, and peptidase.

• 한국생물공학회:학술대회논문집
• /
• 2000.04a
• /
• pp.497-500
• /
• 2000

A biosurfactant producing bacteria strain, D2D2 was selected from diesel-contaminated soil, and identified as Pseudomonas aeroginosa. A glycolipid produced by P. aeroginosa D2D2 was purified by ethyl acetate extraction and adsorption chromatography. The biosurfactant was Identified as glycolipid which has two types of biosurfactants as a results of TLC analysis. The purified glycolipid biosurfactant reduced the surface tension of water to 27 dyne/cm. In time course studies of growth and rhamnolipid production in a minimal salts medium containing 1.5% glucose and 1.5% olive oil, a maximum rhamnolipid yield of $11.45gL^{-1}$ was obtained after 5 days.

• Korean Journal of Agricultural Science
• /
• v.40 no.1
• /
• pp.27-34
• /
• 2013

To investigate the distribution of psychrotrophic bacteria, raw milk was collected from farms in nine different regions located around Kyunggi province in South Korea at four different seasons. Psychrotrophic counts were higher in winter than in other seasons as $3.0{\times}10^4$ CFU/mL (p<0.05). Among nine regions, the population in raw milk sampled from B region was in significantly greater numbers and those from C and D province were in significantly lower numbers than any other regions, $2.4{\times}10^5$ CFU/mL and $8.7{\times}10^3$ CFU/mL, respectively (p<0.05). In addition, among 706 bacterial isolates, the predominant class was Gamma-proteobacteria (81.02%) and genus was Pseudomonas (32.34%), especially Pseudomonas fluorescens (39.46%). Compared to the regional predominance, Acinetobacter johnsonii in A region, Pseudomonas fluorescens in B region, Enterobacter amnigenus in C region, Psychrobacter maritimus in D region, Acinetobacter johnsonii in E region, Acinetobacter haemolyticus in F region, Pseudomonas fluorescens in G region, Acinetobacter jounsonii in H region, and Pseudomonas mucidolens in I region were found.

• Journal of Bio-Environment Control
• /
• v.12 no.4
• /
• pp.207-216
• /
• 2003

Most severe problem in production of potted kalanchoe during summer season is retardation of growth caused by high temperature. The aim of this experiment was aimed to investigate the effects of natural products such as algin-oligosacchride and glucosamine oligosaccharide, plant growth promoting rhizovacteria such as Pseudomonas sp. B and Pseudomonas sp. D2, and AG-solution on the growth of potted kalanchoe under the different root zone temperature in the greenhouse. Growth characteristics in terms of plant height, leaf length, leaf width, leaf area, leaf weight, fresh weight of shoot and root and root length were recorded under three root zone temperatures (25$^{\circ}C$, 30$^{\circ}C$, 35$^{\circ}C$). In 25$^{\circ}C$, the mixed treatment of Pseudomonas sp. B and glucosamine oligosaccharide resulted in the best growth in terms of plant height, leaf area and root weight. In 3-$^{\circ}C$, glucosamine oligosaccharide treatment gave fair result in plant height and leaf weight, but the mixed treatemtn of Pseudomonas sp. D2 and algin-oligosaccharide showed better growth on leaf area and root weight. In 35$^{\circ}C$, the mixed treatment of Pseudomonas sp. B and glucosamine oligosaccharide could greatly improve the plant height, leaf area, leaf weight and root weight. These results demonstrated that the mixed treatment of natural products and microorganisms could overcome the detrimental effects caused by high temeprature in the production of kalanchoe.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.6
• /
• pp.763-770
• /
• 2012

Pseudomonas fluorescens 2112, isolated in Korea as an indigenous antagonistic bacteria, can produce 2,4-diacetylphloroglucinol (2,4-DAPG) and the siderophore pyoveridin2112 for the control of phytophthora blight of red-pepper. P. fluorescens 2112 was classified into a new genotype C among the 17 genotypes of 2,4-DAPG producers, by phlD restriction fragment length polymorphism (RFLP). The colonizing ability of P. fluorescens 2112 in pea rhizosphere was equal to the well-known pea colonizers, P. fluorescens Q8r1 (genotype D) and MVP1-4 (genotype P), after 6 cycling cultivations for 18 weeks. Four tested 2,4-DAPG-producing Pseudomonas spp. could colonize with about a 96% dominance ratio against total bacteria in pea rhizosphere. The strain P. fluorescens 2112 was as good a colonizer as other Pseudomonas spp. genotypes in pea plant growth-promoting rhizobacteria.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2000.04a
• /
• pp.116-123
• /
• 2000

The purpose of this work was to investigate the induction of stress shock proteins (SSPs) in Burkholderia sp. YK-2 in response to 2,4-dichlorophenoxyacetic acid (2,4-D), and Pseudomonas sp. DJ-12 to benzoate, 4-chlorobenzoate (4-CBA), 4-hydroxybenzoate, and biphenyl. The SSPs, which contribute to the resistance of the cytotoxic effect of the toxic aromatic compounds including 2,4-D and 4-CBA, were induced at different concentrations of the compounds in exponentially growing cultures of Burkholderia sp. YK-2 or Pseudomonas sp. DJ-12. This response involved the induction of a 43 kDa DnaK and 41 kDa GroEL proteins in Burkholderia sp. YK-2, characterized by SDS-PAGE and Western blot using the anti-DnaK and anti-GroEL monoclonal antibodies. In Pseudomonas sp. DJ-12, 70 kDa DnaK and 60 kDa GroEL proteins was induced as SSPs, respectively. The total SSPs were analyzed by 2-D PAGE. Survival of Burkholderia sp. YK-2 or Pseudomonas sp. DJ-12 with time in the presence of different concentrations of the compounds was monitored, and viable counts paralleled the induction of the SSPs in these strains. Cells treated with the increased concentrations of toxic compounds showed some destructive openings on the cell envelopes.

• Journal of Microbiology
• /
• v.39 no.4
• /
• pp.334-337
• /
• 2001

The degradative pathway of homoprotocatechuate (HPC) is the bacterial routhe wherby 3,4-dihydrox-yphenylactic acid is catabolized to pyruvate and succinate by a series of sequential reactions . The HPC is catalzed by homoprotocatechuate 2, 3-dioxygenase(HPC-2,3O) to from 5-carboxymethy1-2-hydroxy-muco semialdehyde. In this study, the hha D gene encoding. HPC, 2, 3O was Cloned from the chromo-somal DNA of Pseudomonas sp. DJ-12 and its nucleotide sequence was analyzed. The open reding frame of hpaD gene was found to be composed of 864 nucleotide pairs and to encode a poypetide with 287 amino acide residues. The deduced amino acid sequence of the HPC-2,3O from Pseudomonas. sp. DJ-12 exhibited 60~64% homology with those of the corresponding enzymes from E. coli. Salmonella enterica, and Klebsiella pneumoniae.

• Korean Journal of Pharmacognosy
• /
• v.49 no.2
• /
• pp.108-112
• /
• 2018

Four quinolone alkaloids, 2-heptyl-4-quinolone (1), 2-nonyl-4-quinolone (2), 2-undecyl-4-quinolone (3), and 2-undecen-1'-yl-4-quinolone (4), together with two nitrogen derived benzoic acid derivatives, N-acetylanthranilic acid (5) and o-acetamidobenzamide (6) have been isolated from the Arctic bacterial strain, Pseudomonas aeruginosa. The structures of the compounds were determined by 1D and 2D NMR, and MS experiments, as well as by comparison of their data with published values. To the best of our knowledge, compounds 3-6 were isolated for the first time from P. aeruginosa.