• Food Science and Preservation
• /
• v.8 no.4
• /
• pp.462-468
• /
• 2001

To develop natural food preservative, antimicrobial activity of Pinus densiflora Sieb. et Zucc. (PD) ethanol extract against pathogens were investigated. The growth of pathogens such as Staphylococcus aureus ATCC 29737, Bacillus subtils KCTC 1021, Bacillus megaterium KCTC 3007 and Vibrio parahaemolyticus ATCC 17802 was inhibited as much as 4 to 6 log cycle in tryptic soy broth containing 40mg/㎖ of PD extract but Salmonalla typhimurium ATCC 14028 and Pseudomonas fluorescens ATCC 21541 were not inhibited. The total, gram negative and psychrotrophic bacterial count were inhibited in minced pork containing 40mg/㎖ of PD extract for 20 days at 4$\^{C}$. The sensory quality of hamburger patty such as taste, flavor and overall acceptability were not decreased by the addition of 40mg/㎖ PD(p<0.05).

• Journal of the Korean Chemical Society
• /
• v.13 no.4
• /
• pp.355-364
• /
• 1969

Cross-hybridizations between DNA of two pseudomonads and a xanthomonad suggested that the three DNA types had a considerable section in common. The existence of this common part was proved by hybridization of preselected DNA, i.e. DNA resulting from a previous hybridization between any one set of two DNA types, with the third type. It was thus shown that about 50% of the DNA of the three organisms was similar. This common part was isolated in pure state and its % (G+C) was found to be indentical to the overall base composition of the native DNA. The evolutionary drift in % (G+C) could thus not be detected. The total molecular weight of the chromosornal DNA/bacterial nucleoid was determined to be 2.4 ${\times} 10^9$daltons. It can therefore be estimated that the common putida-fluorescenspelargonii DNA part consists of some 2,000 cistrons. P. putida and P. fluorescens share an additional 1,300 cistrons, and all xanthomonads share at least an additional 1,000 cistrons.

• Mycobiology
• /
• v.35 no.3
• /
• pp.129-134
• /
• 2007

Systemic effect of two plant growth-promoting rhizobacterial (PGPR) strains, viz., Pseudomonas fluorescens (Pf4) and P. aeruginosa (Pag), was evaluated on pea (Pisum sativum) against the powdery mildew pathogen Erysiphe pisi. Foliar spray of the two PGPR strains was done on specific nodal leaves of pea and conidial germination of E. pisi was observed on other nodal leaves, distal to the treated ones. Conidial germination was reduced on distant leaves and at the same time, specific as well as total phenolic compounds increased in the leaves distal to those applied with PGPR strains, thereby indicating a positive correlation. The strains induced accumulation of phenolic compounds in pea leaves and the amount increased when such leaves were get inoculated with E. pisi conidia. Between the two strains, Pag was found to be more effective than Pf4 as its effect was more persistent in pea leaves. Foliar application of PGPR strains for the control of powdery mildew of pea is demonstrated in vitro while correlating it with the increased accumulation of plant phenolics.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.3
• /
• pp.441-449
• /
• 2013

This study was conducted to ferment high quality vinegar by using Omija fruit. Strains of bacteria producing acetic acid were isolated from spoiled Omija wine (OV1 and OV2) and traditional rice vinegar (RA). The bacterium was from optimally-oxidized Omija wine containing 6.0% ethanol and from Omija vinegar with 5.21% acetic acid by 14 days of fermentation. The Omija vinegar got the highest sensory score (5.80) among several commercial vinegars. The Omija vinegar showed a potent antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas fluorescens by the paper disc test, while Omija wine had limited antibacterial activity against S. aureus and P. fluorescens. The diameter of the clear zone formed by the paper disc test using Omija vinegar was not less than 9.5 mm. The DPPH free radical-scavenging activity of Omija wine was higher than that from Omija water extracts. The nitrite scavenging ability of Omija wine (36.98% of all nitrites present) and vinegar (31.14%) was higher than that from Omija water extracts (22.53%). Omija vinegar exhibited strong antibacterial and antioxidant activities. In conclusion, we prepared high quality vinegar from dried Omija.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.4
• /
• pp.471-476
• /
• 1998

Microbiological spoilage of marine fish is complex process occurring by bacteria, yeasts and molds. There have been rare study for saprophytic yeasts although having enormous numbers of bacteriological studies on the spoilage of marine fish. The 14 genera of yeasts isolated from mackerel (Scomber japonicus) with high frequency of occurrence were Candida sp., Rhodotorula sp., Torulopsis sp., Cryptotoccus sp. and Tricosporon sp. Among these ones Candida lipolytica was identified as the strongest proteolytic yeast, then named Candida lipolytica FM5 (C. lipolytica FM5). C. lipolytica FM5 showed optimum growth at $25^{\circ}C$, pH 7.0 and could grow at $5^{\circ}C$ and in medium containing $10\%$ sodium chloride, To evaluate the saprophytic activity of the selected strain, C, lipolytica FM5 and Pseudomonas fluorescens ATCC 17571 which is one of representative spoilage bacteria were individually inoculated into the sterilized fish muscle homogenates, and then pH changes and volatile basic nitrogen (VBN) values were checked during the storage at various temperatures. According to the experimental results, the productions of VBN by C. lipolytica FM5 in the fish muscle homogenates were 50 mg-N/100 g at $5^{\circ}C$, 152 mg-N/100 g at $15^{\circ}C$ and 379 mg-N/100 g at $25^{\circ}C$ for 1 week storage, respectively. Above results were nearly same as in case of Ps. fluorescens ATCC 17571 inoculation. It suggest that sapyophytic yeasts also have important role in spoilage of marine fish.

• Korean Journal of Soil Science and Fertilizer
• /
• v.23 no.1
• /
• pp.53-59
• /
• 1990

The antagonistic fluorescent pseudomonas, which was isolated from continuous cropping rhizosphere of pepper and cucumber, was identified as Pseudomonas fluorescens (P.f.). For further study, transformant was derived from the isolated P.f. after spontaneous mutation to give antibiotic resistance to nalidixic acid and rifampicin as marked strain. Both P.f. and transformant strains were used for this study and the results obtained were summarized as follows. 1. One of the most effective antagonistic strain, KR164, was selected against F. solani, F. oxysporum, R. solani and this strain was identified and classified as Pseudomonas fluorescens biotype IV. 2. Transformant, KR1641, was derived from strain KR164 and both strains had the same biological and biochemical characteristics. 3, Mycelial lysis and abnormal mycelia of plant pathogenic fungi were microscopically observed after simultaneous culture of fungus and given bacterial strain. 4. The length of chinese cabbage to the autolyzed became longer with given bacterial strain in dark culture. 5. Percentage of germination, number of leaves, length of height, and length of root in chinese cabbage in pot experiment were improved by inoculation of given bacterial strain. 6. The number of given bacterial strain kept generally stable until 34 days after inoculation of itself in pot experiment. Inoculation of given bacterial strain did affect the number of plant disease fungi to be decreased but did not affect the number of other bacteria, Bacillus, in pot experiment.

• Journal of Ecology and Environment
• /
• v.33 no.2
• /
• pp.141-147
• /
• 2010

This study compared the antimicrobial activity and chemical composition of two plants used as "Injin" (Korean herbal medicine), namely, Injinho (Artemisia capillaris Thunberg) and Haninjin (Artemisia iwayomogi Kitamura). The ethyl acetate and ether fractions of crude methanol extracts from A. capillaris and A. iwayomogi were tested against three grampositive bacteria (Bacillus cereus, Bacillus subtilis, Staphylococcus aureus), two gram-negative bacteria (Escherichia coli, Pseudomonas fluorescens), and a yeast (Saccharomyceus cerevisiae). The antimicrobial activity of the ethyl acetate and ether fraction of both plants was strong, but that of A. iwayomogi extracts was higher than that of A. capillaris extract for the microbes tested. The minimum inhibitory concentration of the ether and ethyl acetate fraction of A. iwayomogi was highest for P. fluorescens and lowest for S. aureus and E. coli. We analyzed the chemical composition of the ethyl acetate fraction of A. capillaris and A. iwayomogi using gas chromatography-mass spectrometry. The main components of A. capillaris and A. iwayomogi were escoparone (86.82%) and scopoletin (20.47%), respectively.

• Journal of Microbiology
• /
• v.41 no.4
• /
• pp.271-276
• /
• 2003

The inoculation of some microorganisms into a microcosm containing soil from a barren lakeside area at Lake Paro in Kangwon-do enhanced plant growth significantly. The direct and viable counts of soil bacteria and soil microbial activities measured by electron transport system assay and fluorescein diacetate hydrolysis assay were higher in inoculated soil. The plant growth promoting effect of this inoculation may be caused by phytohormone production and the solubilization of insoluble phosphates by the inoculated bacteria. Three inoculated strains of Pseudomonas fluorescens produced several plant growth promoting phytohormones, including indole-3-acetic acid (auxin), which was confirmed by thin layer chromatography and GC/MS. P. fluorescens strain B16 and M45 produced 502.4 and 206.1 mg/l of soluble phosphate from Ca3(PO4)2 and hydroxyapatite, respectively. Bacillus megaterium showed similar solubilization rates of insoluble phosphates to those of Pseudomonas spp. We believe that this plant growth promoting capability may be used for the rapid revegetation of barren or disturbed land.

• The Plant Pathology Journal
• /
• v.32 no.3
• /
• pp.216-227
• /
• 2016

Biological control agents (BCAs) from different microbial taxa are increasingly used to control bacterial wilt caused by Ralstonia solanacearum. However, a quantitative research synthesis has not been conducted on the role of BCAs in disease suppression. Therefore, the present study aimed to meta-analyze the impacts of BCAs on both Ralstonia wilt disease suppression and plant (host) growth promotion. The analysis showed that the extent of disease suppression by BCAs varied widely among studies, with effect size (log response ratio) ranging from -2.84 to 2.13. The disease incidence and severity were significantly decreased on average by 53.7% and 49.3%, respectively. BCAs inoculation also significantly increased fresh and dry weight by 34.4% and 36.1%, respectively on average. Also, BCAs inoculation significantly increased plant yield by 66%. Mean effect sizes for genus Pseudomonas sp. as BCAs were higher than for genus Bacillus spp. Among antagonists tested, P. fluorescens, P. putida, B. cereus, B. subtilis and B. amyloliquefaciens were found to be more effective in general for disease reduction. Across studies, highest disease control was found for P. fluorescens, annual plants, co-inoculation with more than one BCA, soil drench and greenhouse condition were found to be essential in understanding plant responses to R. solanacearum. Our results suggest that more efforts should be devoted to harnessing the potential beneficial effects of these antagonists, not just for plant growth promoting traits but also in mode of applications, BCAs formulations and their field studies should be considered in the future for R. solanacearum wilt disease suppression.

• The Plant Pathology Journal
• /
• v.16 no.6
• /
• pp.312-317
• /
• 2000

The selected five plant growth-promoting rhizobacteria (PGPR) strains, WR8-3 (Pseudomonas fluorescens), WR8-6 (P. putida), WR9-9 (P. fluorescens), WR9-11 (Pseudomonas sp.), and WR9-16 (P. putida) isolated in the rhizosphere of watermelon plants were tested on their growth promotion and control effect against gummy stem rot of watermelon. Strains, WR8-3 and WR9-16 significantly increased stem length of watermelon, and there was a little increase in leaf area, fresh weight and root length when strains, WR8-3, WR9-9 and WR9-16 were treated. Generally, seed treatment was better for plant growth promotion than the soil drench, but there was no significant difference. Seed treatment and soil drench of each bacterial strain also significantly reduced the mean lesion area (MLA) by gummy stem rot, but there was no significant difference between the two treatments. At initial inoculum densities of each strain ranging from 10$^6\;to\;10^{15}$ cfu/g seed, approximately the same level of disease resistance was induced. But resistance induction was not induced at the initial inoculum density of 10$^3$ cfu/g seed. Resistance was induced by treating the strains, WR9-9, WR9-11 and WR9-16, on all of four watermelon varieties tested, and there was no significant difference in the decrease of gummy stem rot among varieties. Populations of the strains treated initially at log 9-10 cfu/g seed, followed with a rapid decrease from planting day to 1 week after planting, but the population density was maintained above log 5.0 cfu/g soil until 4 weeks after planting. Generally no or very weak in vitro antagonism was observed at the strains treated excepting WR9-11. Rifampicin-resistant bacteria which had been inoculated were not detected in the stems or leaves, which suggesting that the bacterium and the pathogens remained spatially separated during the experiment. This is the first report of rsistance induction in watermelon to gummy stem rot by PGPR strains.