• Journal of Microbiology and Biotechnology
• /
• v.29 no.8
• /
• pp.1299-1309
• /
• 2019

As an opportunistic bacterial pathogen, Pseudomonas aeruginosa PAO1 contains two phenazine-producing gene operons, phzA1B1C1D1E1F1G1 (phz1) and phzA2B2C2D2E2F2G2 (phz2), each of which is independently capable of encoding all enzymes for biosynthesizing phenazines, including phenazine-1-carboxylic acid and its derivatives. Other previous study reported that the RpoS-deficient mutant SS24 overproduced pyocyanin, a derivative of phenazine-1-carboxylic acid. However, it is not known how RpoS mediates the expression of two phz operons and regulates pyocyanin biosynthesis in detail. In this study, with deletion of the rpoS gene in the $PA{\Delta}phz1$ mutant and the $PA{\Delta}phz2$ mutant respectively, we demonstrated that RpoS exerted opposite regulatory roles on the expression of the phz1and phz2 operons. We also confirmed that the phz1 operon played a critical role and especially biosynthesized much more phenazines than the phz2 operon when the rpoS gene was knocked out in P. aeruginosa. By constructing the translational reporter fusion vector lasR'-'lacZ and the chromosomal fusion mutant $PA{\Delta}lasR::lacZ$, we verified that RpoS deficiency caused increased expression of lasR, a transcription regulator gene in a first quorum sensing system (las) that activates overexpression of the phz1 operon, suggesting that in the absence of RpoS, LasR might act as an intermediate in overproduction of phenazine biosynthesis mediated by the phz1 operon in P. aeruginosa.

• The Journal of Korean Medicine
• /
• v.32 no.1
• /
• pp.130-140
• /
• 2011

Objectives: This study was performed in order to investigate the anti-hemolytic effect of Chunghyuljihwang-tang(CHJHT, Qingxuedihuang-tang) on phenylhydrazine-induced hemolytic anemia in Rats. Materials and Methods: Hemolytic anemia model of rats were induced by phenylhydrazine(PHZ, 40mg/kg/day, i.p.) for 3days. Male Sprague-Dawley rats were divided into three groups for their treatment. Normal group was injected normal saline for 3 days with distilled water(d.w.) orally, control group was injected PHZ for 3 days with d.w. and CHJHT group was injected PHZ for 3 days with administration of CHJHT for 10 days. RBC(Red blood cell), Hb(hemoglobin), mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, reticulocyte were determined on day 0, 4, 7, 10. Body weight was investigated on day 0, 2, 4, 6, 8, 10 and the weight of spleen was measured on day 10. Results: For CHJHT group, the levels of RBC and Hb were significantly higher than control group on day 4, and the concentration of hemoglobin on day 7 was increased more than control group. Moreover, reticulocyte was significantly decreased on day 10 more than control group. These results could be concluded that CHJHT suppressed the hemolytic anemia by PHZ and improved hematological values of anemia earlier.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.3
• /
• pp.326-330
• /
• 2012

Antifungal metabolites were isolated from a culture of Pseudomonas aurantiaca IB5-10. Chemical structures of the metabolites were elucidated as phenazine-1-carboxylic acid (PCA; 1), 2-hydroxyphenazine (2-OH-PHZ; 2), and cyclo-(L-Pro-L-Val; 3), respectively, based on spectroscopic methods. Among them, 3 was isolated for the first time from this strain. The antifungal activities of 1-3 were evaluated against a variety of plant pathogens. To the best of our knowledge, the antifungal activities of 3 against plant fungal pathogens have been evaluated for the first time in this work. PCA (1) showed the most potent antifungal activities against Phytophthora capsici, Rhizoctonia solani AG-1(IA), and Pythium ultimum with MICs (${\mu}g/ml$) of less than 1.0, 1.3, and 2.0, respectively. On the other hand, 2-OH-PHZ (2) showed potent antifungal activity against R. solani AG-1(IA) with the MIC (${\mu}g/ml$) of 2.0, whereas it showed moderate antifungal activity against P. ultimum with the MIC (${\mu}g/ml$) of 50.0. In addition, 3 showed antifungal activity against only R. solani AG-1(IA).

• Proceedings of the Zoological Society Korea Conference
• /
• 1996.10a
• /
• pp.155.1-155
• /
• 1996

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
• /
• 1997.10b
• /
• pp.202.1-202
• /
• 1997

No Abstract, See Full Text

• Journal of People, Plants, and Environment
• /
• v.24 no.5
• /
• pp.519-527
• /
• 2021

Background and objective: This study was conducted to establish a Plant Hardiness Zone (PHZ) map, investigate the effect of global warming on changes in PHZ, and elucidate the difference in the distribution of evergreen trees between the central and southern region within hardiness Zone 7b in Korea. Methods: Mean annual extreme minimum temperature (EMT) and related temperature fluctuation data for 40 years (1981 to 2020) in each of the meteorological observation points were extracted from the Open MET Data Portal of the Korea Meteorological Administration. Using EMT data from 60 meteorological observation points, PHZs were classified according to temperature range in the USDA Plant Hardiness Zone Map. Changes in PHZs for each decade related to the effects of global warming were analyzed. Temperature fluctuation before and after the day of EMT were analyzed for 4 areas of Seoul, Suwon, Suncheon, and Jinju falling under Zone 7b. For statistical analysis, descriptive statistics and ANOVA were performed using the IBM SPSS 22 Statistics software package. Results: Plant hardiness zones in Korea ranged from 6a to 9b. Over four decades, changes to warmer PHZ occurred in 10 areas, especially in colder ones. Based on the analysis of daily temperature fluctuation, the duration of sub-zero temperatures was at least 2 days in Seoul and Suwon, while daily maximum temperatures were above zero in Suncheon and Jinju before and after EMT day. Conclusion: It was found that the duration of sub-zero temperatures in a given area is an important factor affecting the distribution of evergreen trees in PHZ 7b.

• Proceedings of the Zoological Society Korea Conference
• /
• 1998.10b
• /
• pp.240.2-240
• /
• 1998

No Abstract, See Full Text

• Korean Journal of Plant Tissue Culture
• /
• v.26 no.2
• /
• pp.121-126
• /
• 1999

Calli were induced from the petiole explants of Pimpinella brachycarpa on MS medium supplemented with 0.5 mg/L 2,4-D and 0.1 mg/L BA after four weeks of culture. Compact clusters of small and dense cells among these calli were selected and suspension-cultured as the source of embryogenic calli. When transferred to MS medium with 0.1 mg/L NAA, the suspension-cultured cells grew to embryogenic callus. Somatic embryos derived from these embryogenic calli developed into plantlets. The cDNA library was constructed in the embryogenic callus and in order to screen the cDNA library, these cDNAs were plated at a density 1.5 $\times$ 10^5 plaques per 15 cm petridish. Among 19 clones showing preferential hybridization with petiole HD-Zip gene, five clones were obtained after second screening. Four clones among them, were highly homologous to P. brachycarpa shoot-tip Phz4 gene, but one clone, Phc5 was about 1.5 kb which has an extra 163 bp to 5' upstream of Phz4. The Phc5 was 1,531 bp containing poly A tails of 18 bases. ATG start codon for Phc5, was located at position 284 with an open reading frame of 906 by which encodes a polypeptide of 302 amino acids. The Phc5 protein revealed that the polypeptides between 135 and 195 contain a homeodomain as the `leucine zipper' motif.

• The Journal of Internal Korean Medicine
• /
• v.32 no.1
• /
• pp.1-9
• /
• 2011

Objectives : This study was performed in order to investigate the effect of Panax notoginseng(SCG) on phenylhydrazine (PHZ)-induced hemolytic anemia in rats. Materials and Methods : Rats were divided equally into 3 groups (Normal, Control, SCG). Anemic model rats (Control, SCG) were induced by the treatment of PHZ (40mg/kg/day, i.p.) for 3 days. Red blood cell, hemoglobin, reticulocyte count, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration were determined on days 0, 4, 7 and 10. Body weight was investigated on days 0, 2, 4, 6, 8, 10 and weight of spleen was measured on day 10. Results : In the SCG group, significantly higher levels of RBC was found on day 4 and higher concentration of Hb on days 4, 7 and 10. Furthermore, reticulocyte count was dramatically lower on day 10 compared to the control group. Conclusions : These results suggest that SCG may be beneficial in the treatment of hemolytic anemia.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.5
• /
• pp.672-680
• /
• 2015

As a global regulatory gene in Streptomyces, afsR can activate the biosynthesis of many secondary metabolites. The effect of afsR on the biosynthesis of a phenazine metabolite, lomofungin, was studied in Streptomyces lomondensis S015. There was a 2.5-fold increase of lomofungin production in the afsR-overexpressing strain of S. lomondensis S015 N1 compared with the wild-type strain. Meanwhile, the transcription levels of afsR and two important genes involved in the biosynthesis of lomofungin (i.e., phzC and phzE) were significantly upregulated in S. lomondensis S015 N1. The optimization of metal chlorides was investigated to further increase the production of lomofungin in the afsR-overexpressing strain. The addition of different metal chlorides to S. lomondensis S015 N1 cultivations showed that CaCl₂, FeCl₂, and MnCl₂ led to an increase in lomofungin biosynthesis. The optimum concentrations of these metal chlorides were obtained using response surface methodology. CaCl₂ (0.04 mM), FeCl₂ (0.33 mM), and MnCl₂ (0.38 mM) gave a maximum lomofungin production titer of 318.0 ± 10.7 mg/l, which was a 4.1-fold increase compared with that of S. lomondensis S015 N1 without the addition of a metal chloride. This work demonstrates that the biosynthesis of phenazine metabolites can be induced by afsR. The results also indicate that metal chlorides addition might be a simple and useful strategy for improving the production of other phenazine metabolites in Streptomyces.