• Microbiology and Biotechnology Letters
• /
• v.21 no.3
• /
• pp.239-246
• /
• 1993

Producing an extracellular alkaline lipase, this isolate JM123 was identified as a Pseudomonas aeruginosa strain from the results of the analyses of its morphological, biochemical and physiological properties. This strain showed the highest productivity of alkaline lipase when grown at pH 9.0 and 30C for 13-20 hours in the medium of 2% starch, 1% soytone, 0.5% peptone and 1% MgSO4.7H2O. However, this enzyme was greatly repressed when grown in the glucose containing medium. The culture broth was fractionated by the order of the ammonium sulfate precipitation, Sephadex G-200 gel filtration, DEAE-cellulose column chromatography, and Sephadex G-150 gel filtration.

• Journal of Veterinary Clinics
• /
• v.36 no.5
• /
• pp.245-247
• /
• 2019

Taylorella equigenitalis (T. equigenitalis), Klebsiella pneumoniae (K. pneumoniae), and Pseudomonas aeruginosa (P. aeruginosa) are sexually transmittable bacteria known to cause venereal diseases (VD) in horses. T. equigenitalis causes contagious equine metritis (CEM), which is a considerable concern for equine breeding industry. K. pneumoniae and P. aeruginosa may cause endometritis and infertility in susceptible mares. The purpose of this study was to investigate the prevalence of these bacteria among breeding Thoroughbreds in South Korea. External genital swabs were collected from 178 breeding Thoroughbreds, including 11 stallions and 167 mares. The samples were tested using a commercial multiplex real-time PCR kit. T. equigenitalis, P. aeruginosa, and K. pneumoniae were present in 5.6%, 7.3%, and 5.6% of tested Thoroughbreds, respectively. The results highlight the need for regular testing of South Korean Thoroughbreds, particularly those used for breeding, for these bacteria. The regular pre-breeding test for these bacteria will prevent health complications for the horse and financial losses for the owner as a result of VD.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.10
• /
• pp.1701-1707
• /
• 2016

Lipoxygenase (LOX) is an industrial enzyme with wide applications in food and pharmaceutical industries. The available structure information indicates that eukaryotic LOXs consist of N terminus β-barrel and C terminus catalytic domains. However, the latest crystal structure of Pseudomonas aeruginosa LOX shows it is significantly different from those of eukaryotic LOXs, including the N-terminal helix domain. In this paper, the functions of this N-terminal helix domain in the soluble expression and catalysis of P. aeruginosa LOX were analyzed. Genetic truncation of this helix domain resulted in an insoluble P. aeruginosa LOX mutant. The active C-terminal domain was obtained by dispase digestion of the P. aeruginosa LOX derivative containing the genetically introduced dispase recognition sites. This functional C-terminal domain showed raised substrate affinity but reduced catalytic activity and thermostability. Crystal structure analyses demonstrate that the broken polar contacts connecting the two domains and the exposed hydrophobic substrate binding pocket may contribute to the insoluble expression of the C terminus domain and the changes in the enzyme properties. Our data suggest that the N terminus domain of P. aeruginosa LOX is required for its soluble expression in E. coli, which is different from that of the eukaryotic LOXs. Besides this, this N-terminal domain is not necessary for catalysis but shows positive effects on the enzyme properties. The results presented here provide new and valuable information on the functions of the N terminus helix domain of P. aeruginosa LOX and further improvement of its enzyme properties by molecular modification.

• Korean Journal of Microbiology
• /
• v.45 no.4
• /
• pp.362-367
• /
• 2009

Among total 176 strains with antialgal effects isolated from So-ok stream in Korea, Pseudomonas aeruginosa AJ1 showed the highest removal efficiency for an algal species Microcystis aeruginosa (clear zone of diameter 50.0 mm on algal lawn after 20 days). The algal growth was suppressed even when the supernatant of AJ1 culture was applied, suggesting that extracellular substances are responsible for its antialgal activity. The removal activity of AJ1 was optimal under the following condition: pH 8, $30^{\circ}C$, and mannitol as a carbon source. The antialgal activity of AJ1 appeared to be dependent of the growth phase of M. aeruginosa, i.e., the highest at the early phase, but not its own phase. As expected, the algicidal effect was improved as the amount of the treated supernatant was increased; the highest removal efficiency (80.3%) was achieved when 40 ml/L of the supernatant was used. Interestingly, however, the removal rate was opposite. The highest removal rate ($8.2{\mu}g$ chl-a/ml supernatant/day) was achieved when low concentration (10 ml/L) was applied. These results suggest that P. aeruginosa AJ1 is a promising biological agent to control the problematic algal bloom.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.626-629
• /
• 2000

The Pseudomonas aeruginosa BYK-2(KCTC 18012p) produced three kinds of glycolipids on olive oil as a substrate and purified two types of major glycolipids(Rf=0.48, BS-1; Rf=0.65, BS-2) using silica gel chromatography, TLC, HPLC, etc. From the analysis of the chemical structure, the glycolipid of BS-1 was estimated as rhamnolipid($2-O-{\alpha}-L-rhamnopyranosyl- {\alpha}-L-rhamnopyranosyl-{\beta}-hydroxyldecanoyl-{\beta}-hydroxydecanoic$ acid; M.W. 650) and BS-2 was detected as rhamnolipid methyl ester($2-O-{\alpha}-L-rhamnopyranosyl-{\alpha}-L-rhamnopyranosyl-{\beta}-hydroxyldecanoyl-{\beta}-hydroxydecanoic$ acid methyl ester; M.W. 664) by FT-IR, FAB Mass spectrometry, $^1H-NMR$, $^{13}C$ FT-NMR, DEPT, 2D-NMR (TOCSY, RELAY, NOESY, HSQC, HMBC). In particular, It was found that a marine bacterium Pseudomonas aeruginosa BYK-2(KCTC 18012P) remarkably produced rhamnolipid and rhamnolipid methyl ester simultaneously.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.8
• /
• pp.1539-1548
• /
• 2017

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen that commonly causes fatal infections in cystic fibrosis and burn patients as well as in patients who are hospitalized or have impaired immune systems. P. aeruginosa infections are difficult to treat owing to the high resistance of the pathogen to conventional antibiotics. Despite several efforts, no effective prophylactic vaccines against P. aeruginosa are currently available. In this study, we investigated the activity of the CIA06 adjuvant system, which is composed of alum and de-O-acylated lipooligosaccharide, on a P. aeruginosa outer membrane protein (OMP) antigen vaccine in mice. The results indicated that CIA06 significantly increased the antigen-specific IgG titers and opsonophagocytic activity of immune sera against P. aeruginosa. In addition, the antibodies induced by the CIA06-adjuvanted vaccine exhibited higher cross-reactivity with heterologous P. aeruginosa strains. Finally, mice immunized with the CIA06-adjuvanted vaccine were effectively protected from lethal P. aeruginosa challenge. Based on these data, we suggest that the CIA06 adjuvant system might be used to promote the immunogenicity and protective efficacy of the P. aeruginosa OMP vaccine.

• Microbiology and Biotechnology Letters
• /
• v.22 no.1
• /
• pp.92-98
• /
• 1994

The bacteria which secrete surface-active agent and decrease the surface tension of culture broth were isolated from soil samples. Among them, biosurfactant producing strain KK-7 was selected and emulsification was also detected. The KK-7 produced biosurfactant not only lipid but also glucose by using carbon source. Taxonomical characterization tests have demostrated the strain KK-7 to be Pseudomonas aeruginosa. The media composition of the P. aeruginosa KK-7 for the biosurfactant production was 1% glucose, 0.5% tryptone, 0.2% yeast extract, 0.15% potas sium phosphate mono-dibasic, 0.05% MgSO$_{4}$, initial pH 8.5, at 30$\circ $C for 2 days. In this condition, the concentration of biosurfactant was reached CMC 5 in the culture broth. Surface active material was produced maximum at stationary8 phase, but emulsification power was higher at log phase than stationary phase. It was considered that P. aeruginosa KK-7 produced biosurfactant more than one type having defferent properties and each maximum production time was different. The minimun surface tension of biosurfactant in 50 mM Tris buffer (pH8.0) was 28 dyn/cm, and CMC was 1 g/L.

• Applied Biological Chemistry
• /
• v.36 no.6
• /
• pp.428-433
• /
• 1993

A strain that inhibited the growth of Pellicularia sasakii was isolated from the soil and identified as Pseudomonas aeruginosa 3120. A dark brownish antibiotic, MRL3120 isolated and purified from the culture broth of P. aeruginosa 3120 was soluble in ethylacetate, chloroform and methanol, and it was active against gram-positive and negative bacteria as well as fungi. The structure of MRL3120 was identified as a chelate compound consisting of two N-methyl-N-thioformyl-hydroxylamine and a copper ion by the analysis of UV, IR, and EI-MS spectra and other physico-chemical properties and supposed to have a structure of fluopsin C related compound. Addition of $CuSO_4$ into the fermentation medium containing soybean meal increased antifungal activity but no activity was found in the presence of EDTA (0.1%, v/v). However antibiotic MRL3120 was not produced in the fermentation medium containing soytone instead of soybean meal but it was rapidly produced by the addition of $CuSO_4$.

• Korean Journal of Microbiology
• /
• v.50 no.4
• /
• pp.281-284
• /
• 2014

Immune defense responses against Pseudomonas aeruginosa infection play an important role in maintaining homeostasis in the human body. Previously, we reported that expression of the bradykinin receptor (BR) is induced in response to P. aeruginosa infection. However, the factors responsible for the induction was uncertain. Here, we found that the type III secretion system (T3SS) is responsible for the induction of BR expression, and nucleoside diphosphate kinase (Ndk), as a novel T3SS effector, mediates the upregulation. The Ndk-mediated expression of BR was not induced by fliC mutant treatment, indicating the involvement of flagellin, one of the well-known pathogen-associated molecular patterns (PAMPs). Taken together, this study demonstrated that Ndk cooperates with flagella in the development of defense responses against P. aeruginosa infection.

• Journal of Korean society of Dental Hygiene
• /
• v.14 no.4
• /
• pp.601-608
• /
• 2014

Objectives : The purpose of the study is to examine the apoptotic effects of Pseudomonas aeruginosa exotoxin A(PEA) in squamous cell carcinoma(SCC) 25 cells. Methods : Cell growth reduction and apoptosis induced by PEA were confirmed by WST-1 assay, Hoechst 33258 staining, flow cytometry analysis, and Western blot assay. Results : The PEA treatment decreased the cell viability in a dose and time dependent manner: control; $100{\pm}0^e$(p<0.01), 0.1875 nM; $87{\pm}4.36^d$(p<0.01), 0.375 nM; $82{\pm}0.58^d$(p<0.01), 0.75 nM; $72{\pm}1.67^c$(p<0.01), 1.5 nM; $51{\pm}1.53^{bc}$(p<0.01), 7.5 nM; $31{\pm}1.20^{ab}$(p<0.01), 15 nM; $26{\pm}0.67^a$(p<0.01), control; $100{\pm}0^a$(p<0.05), 24 h; $51{\pm}1.53^b$(p<0.05), 48 h; $16{\pm}0.5^c$(p<0.05), 72 h; $12{\pm}1.67^d$%(p<0.05). The PEA was observed on SCC 25 cells with the half maximal inhibitory concentration(IC50) value of 1.5 nM at 24 hours. The PEA treated SCC 25 cells demonstrated several types of apoptotic indications, such as nuclear condensation, the increase of sub G1, and the cleavage of PARP-1 and DFF 45. Conclusions : PEA showed anti-cancer activity against SCC 25 cells via apoptosis. PEA may potentially contribute to human oral cancer treatment.