• Journal of Nutrition and Health
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• 제28권11호
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• pp.1065-1072
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• 1995

Mugwort was successively fractionated with n-hexane, chloroform, ethyl acetate, n-butanol and water and the fractions were evaluated by their growth-promoting activites for Bifidobacterium sp. in vitro experiments. The growths of Bifidobacterium adolescentis, B. bifidum, B. infantis and B.longum were enhanced with the addition of the water fraction, while the fractions of chloroform and ethylacetate inhibited Clostridium perfringens. When the wate fraction was added to media at a concentration of 0.01-0.5%(w/v), the growhts of Bifidobacterium sp. were increased according to the concentration of water fraction used. The water fraction stimulated also the growth of lactobacillus acidophillus, whereas those of E. coli and Enterococcus faecalis were not affected. The growth-promoting activity of water fraction was stable at the range of pH 2 to pH 10 and kept in thermal treatment at 10$0^{\circ}C$ for 30 minutes.

• Journal of Applied Biological Chemistry
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• 제43권4호
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• pp.264-268
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• 2000

High activity of acidic ethylacetate extract from the culture supernatant of ginseng growth-promoting bacterium Pseudomonas fluorescens KGPP 207 and its fractions were demonstrated through wheat coleoptile bioassay. The following auxins and auxin-like compounds were identified in these fractions by combined gas chromatography-mass spectrometry: indole-3-acetic acid, indole-3-acetic acid methyl and ethyl ester, indole-3-butyric acid, indole-3-lactic acid and its methyl ester, indole-3-propionic acid, indole-3-pyruvic acid, p-hydroxyphenyl acetic acid, p-hydroxyphenyl acetic acid methyl and ethyl ester, phenyl acetic acid and its methyl ester. The bacterium KGPP 207 belongs to the strain of P. fluorescens which produces plant growth regulators and its beneficial effect on the ginseng growth may be due to the formation of the identified compounds.

• Journal of Microbiology and Biotechnology
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• 제20권11호
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• pp.1577-1584
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• 2010

In total, 140 halotolerant bacterial strains were isolated from both the soil of barren fields and the rhizosphere of six naturally growing halophytic plants in the vicinity of the Yellow Sea, near the city of Incheon in the Republic of Korea. All of these strains were characterized for multiple plant growth promoting traits, such as the production of indole acetic acid (IAA), nitrogen fixation, phosphorus (P) and zinc (Zn) solubilization, thiosulfate ($S_2O_3$) oxidation, the production of ammonia ($NH_3$), and the production of extracellular hydrolytic enzymes such as protease, chitinase, pectinase, cellulase, and lipase under in vitro conditions. From the original 140 strains tested, on the basis of the latter tests for plant growth promotional activity, 36 were selected for further examination. These 36 halotolerant bacterial strains were then tested for 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Twenty-five of these were found to be positive, and to be exhibiting significantly varying levels of activity. 16S rRNA gene sequencing analyses of the 36 halotolerant strains showed that they belong to 10 different bacterial genera: Bacillus, Brevibacterium, Planococcus, Zhihengliuella, Halomonas, Exiguobacterium, Oceanimonas, Corynebacterium, Arthrobacter, and Micrococcus. Inoculation of the 14 halotolerant bacterial strains to ameliorate salt stress (150 mM NaCl) in canola plants produced an increase in root length of between 5.2% and 47.8%, and dry weight of between 16.2% and 43%, in comparison with the uninoculated positive controls. In particular, three of the bacteria, Brevibacterium epidermidis RS15, Micrococcus yunnanensis RS222, and Bacillus aryabhattai RS341, all showed more than 40% increase in root elongation and dry weight when compared with uninoculated salt-stressed canola seedlings. These results indicate that certain halotolerant bacteria, isolated from coastal soils, have a real potential to enhance plant growth under saline stress, through the reduction of ethylene production via ACC deaminase activity.

• Journal of Microbiology and Biotechnology
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• 제20권11호
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• pp.1491-1499
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• 2010

Rhizosphere microorganisms possessing phytase activity are considered important for rendering phytate-phosphorus (P) available to plants. In the present study, the Citrobacter braakii phytase gene (appA) was overexpressed in rhizobacteria possessing plant growth promoting (PGP) traits, for increasing their potential as bioinoculants. AppA was cloned under the lac promoter in the broadhost-range expression vector pBBR1MCS-2. Transformation of the recombinant construct pCBappA resulted in high constitutive phytase activity in all of the eight rhizobacterial strains belonging to genera Pantoea, Citrobacter, Enterobacter, Pseudomonas (two strains), Rhizobium (two strains), and Ensifer that were studied. Transgenic rhizobacterial strains were found to display varying levels of phytase activity, ranging from 10-folds to 538-folds higher than the corresponding control strains. The transgenic derivative of Pseudomonas fluorescens CHA0, a well-characterized plant growth promoting rhizobacterium, showed the highest expression of phytase (~8 U/mg) activity in crude extracts. Although all transformants showed high phytase activity, rhizobacteria having the ability to secrete organic acid showed significantly higher release of P from Ca-phytate in buffered minimal media. AppA overexpressing rhizobacteria showed increased P content, and dry weight (shoot) or shoot/ root ratio of mung bean (Vigna radiata) plants, to different extents, when grown in semisolid agar (SSA) medium containing Na-phytate or Ca-phytate as the P sources. This is the first report of the overexpression of phytase in rhizobacterial strains and its exploitation for plant growth enhancement.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1724-1734
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• 2010

A phosphate-solubilizing bacterial strain isolated from Hippophae rhamnoides rhizosphere was identified as Rahnella sp. based on its phenotypic features and 16S rRNA gene sequence. The bacterial strain showed the growth characteristics of a cold-adapted psychrotroph, with the multiple plant growth-promoting traits of inorganic and organic phosphate solubilization, 1-aminocyclopropane-1-carboxylate-deaminase activity, ammonia generation, and siderophore production. The strain also produced indole-3-acetic acid, indole-3-acetaldehyde, indole-3-acetamide, indole-3-acetonitrile, indole-3-lactic acid, and indole-3-pyruvic acid in tryptophan-supplemented nutrient broth. Gluconic, citric and isocitric acids were the major organic acids detected during tricalcium phosphate solubilization. A rifampicin-resistant mutant of the strain exhibited high rhizosphere competence without disturbance to the resident microbial populations in pea rhizosphere. Seed bacterization with a charcoal-based inoculum significantly increased growth in barley, chickpea, pea, and maize under the controlled environment. Microplot testing of the inoculum at two different locations in pea also showed significant increase in growth and yield. The attributes of cold-tolerance, high rhizosphere competence, and broad-spectrum plant growth-promoting activity exhibited the potential of Rahnella sp. BIHB 783 for increasing agriculture productivity.

• 한국균학회지
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• 제43권1호
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• pp.71-76
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• 2015

수생식물 샘플은 낙동강과 금호강이 만나는 달성습지에서 자라풀을 채집하였다. 자라풀의 뿌리에서 내생균류를 분리하고 형태가 다른 균주를 관찰하여 최종적으로 16개 균주를 선발하였다. 내생균류의 배양여과액은 식물생장촉진활성 검정을 위하여 난장이벼에 처리하여 스크리닝하였으며, HD1008 균주가 식물생장촉진활성이 가장 높은 것으로 확인되었다. HD1008 균주의 배양여과액을 HPLC와 GC/MS-SIM을 이용하여 분석하였고, HD1008 균주가 식물호르몬인 지베렐린 $GA_1$ (1.2 ng/100 mL)과 $GA_4$ (5 ng/100 mL) 를 생산하는 것을 정량분석을 통하여 확인하였다. 또한, HD1008균주의 beta-tubulin 유전자 염기서열을 이용하여 동정에 이용하였으며, 분자적인 방법과 형태적인 방법으로 관찰하였을 때, 지베렐린을 생산하는 새로운 P. trzebinskii로 동정되었다.

• The Plant Pathology Journal
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• 제34권3호
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• pp.218-235
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• 2018

Plant growth promoting rhizobacteria and endophytic bacteria were isolated from different varieties of turmeric (Curcuma longa L.) from South India. Totally 50 strains representing, 30 PGPR and 20 endophytic bacteria were identified based on biochemical assays and 16S rDNA sequence analysis. The isolates were screened for antagonistic activity against Pythium aphanidermatum (Edson) Fitzp., and Rhizoctonia solani Kuhn., causing rhizome rot and leaf blight diseases in turmeric, by dual culture and liquid culture assays. Results revealed that only five isolates of PGPR and four endophytic bacteria showed more than 70% suppression of test pathogens in both assays. The SEM studies of interaction zone showed significant ultrastructural changes of the hyphae like shriveling, breakage and desication of the pathogens by PGPR B. cereus (RBacDOB-S24) and endophyte P. aeruginosa (BacDOB-E19). Selected isolates showed multiple Plant growth promoting traits. The rhizome bacterization followed by soil application of B. cereus (RBacDOB-S24) showed lowest Percent Disease Incidence (PDI) of rhizome rot and leaf blight, 16.4% and 15.5% respectively. Similarly, P. aeruginosa (BacDOB-E19) recorded PDI of rhizome rot (17.5%) and leaf blight (17.7%). The treatment of these promising isolates exhibited significant increase in plant height and fresh rhizome yield/plant in comparison with untreated control under greenhouse condition. Thereby, these isolates can be exploited as a potential biocontrol agent for suppressing rhizome rot and leaf blight diseases in turmeric.

• Journal of Preventive Medicine and Public Health
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• 제48권5호
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• pp.231-238
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• 2015

Objectives: The present study aimed to analyze the factors that could affect the health-promoting behaviors of North Korean adolescent refugees residing in South Korea. Methods: Questions about their sociodemographic variables, subjective health status, healthy living habits, and health-promoting behaviors were asked. Results: Statistically significant differences were found in religion (t=2.30, p<0.05), having family members in South Korea (t=2.02, p<0.05), and subjective health status (t=4.96, p<0.01). Scores on health-responsible behaviors were higher with higher age (t=2.90, p<0.01) and for subjects without family or friends (t=2.43, p<0.05). Higher physical-activity behaviors were observed in males (t=3.32, p<0.01), in those with better subjective health status (t=3.46, p<0.05) and lower body mas index (t=3.48, p<0.05), and in smokers (t=3.17, p<0.01). Nutritional behaviors were higher in those who followed a religion (t=2.17, p<0.05). Spiritual growth behaviors were higher in those who followed a religion (t=4.21, p<0.001), had no family in South Korea (t=2.04, p<0.05), and had higher subjective health status (t=5.74, p<0.01). Scores on interpersonal relationships and stress-management behaviors were higher for those with higher subjective health status. A multiple regression analysis showed greater effects on health-promoting behaviors when subjective health status was better. Older people and non-smokers exhibited more health-responsible behaviors, while more physical-activity behaviors and spiritual growth activities were observed when subjective health status was better. Interpersonal relationship behaviors had positive effects on those with good subjective heath status and on non-smokers. Conclusions: Based on the results of the current study, an alternative was suggested for promoting health in North Korean adolescent refugees.

• Food Science and Biotechnology
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• 제15권4호
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• pp.543-548
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• 2006

The effects of food grade fructooligosaccharide (FOS), isomaltooligosaccharide (MOS), galactooligosaccharide (GOS), and inulin on the growth of five strains of bifidobacteria in fermented milk were investigated. Their effect on culture viability during refrigerated storage was also determined. FOS showed the highest growth-promoting activity for all bifidobacteria except for Bifidobacterium bifidum. Growth rates of B. adolescentis, B. breve, and B. infantis were stimulated by oligosaccharides and inulin, whereas B. longum growth was stimulated by the oligosaccharides but not inulin. In contrast, growth of B. bifidum was enhanced only by inulin. Both acetic and lactic acid production by Bifidobacterium spp. was also enhanced in the presence of 5.0% oligosaccharides. The viability of bifidobacteria cultured with oligosaccharides and inulin, particularly with FOS, was significantly higher than control cultures after 4 weeks of refrigerated storage. The utilization of oligosaccharides is likely to enhance the growth rate, activity, and viability of bifidobacteria.

• 미생물학회지
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• 제51권1호
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• pp.14-20
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• 2015

동해안에 자생하는 해안식물인 개질경이를 채집하였고, 뿌리로부터 형태적으로 다른 내생균류 20균주를 선발하였다. 개질경이 뿌리에 공생하는 내생균류의 ITS-rDNA 염기서열을 분석하였으며, 분리된 내생균류의 유연관계는 Bayesian 프로그램을 이용하여 계통분석을 하였다. 모든 내생균류의 농축배양여과액을 난장이벼에 처리하여 식물생장촉진활성을 스크리닝하였고, 분리된 균류 중에서 E/PC/10/1 균주가 생장촉진활성이 우수한 것으로 확인되었다. E/PC/10/1 균주의 배양여과액을 HPLC와 GC/MS-SIM을 이용하여 분석한 결과, 식물호르몬인 지베렐린 $GA_1$, $GA_3$, $GA_4$가 정량분석 되었다. 그리고 E/PC/10/1 균주의 명확한 동정을 위하여, beta-tubulin 유전자 염기서열을 이용한 분자적인 방법과 현미경을 이용한 형태적인 방법으로 동정하였다. 최종적으로 E/PC/10/1 균주는 GAs을 생산하는 새로운 P. spinulosum으로 동정되었다.