• Journal of Microbiology and Biotechnology
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• v.19 no.1
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• pp.99-107
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• 2009

Strain PUPC1 produces an antifungal protease as well as plant growth promoting enzymes such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase and phosphatase. Morphological, cultural, and physiological characteristics as well as 16S rRNA gene-sequence-based phylogenetic analysis confirmed the taxonomic affiliation of PUPC1 as Chryseobacterium aquaticum. The optimum growth of PUPC1 was observed at pH 6.0 and $30^{\circ}C$, and maximum protease production was observed in medium B amended with 1% tryptone, 0.5% sucrose, and 0.005% $MnCl_2$. The protease was purified by ammonium sulfate precipitation, Sephadex G-75 gel filtration chromatography, and electroelution from preparative SDS-PAGE. The protease had a molecular mass of 18.5 kDa. The optimum pH and temperature stability of the protease were pH 5.0-10.0 and temperature $40-70^{\circ}C$. Chryseobacterium aquaticum PUPC1 and its protease showed a broad-spectrum antifungal activity against phytopathogenic fungi. Strain PUPC1 also exhibited plant growth promoting traits. The objective of the present investigation was to isolate a strain for agricultural application for plant growth promotion and biocontrol of fungal diseases.

• The Plant Pathology Journal
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• v.27 no.2
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• pp.164-169
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• 2011

Previous studies have addressed the management of phyllosphere pathogens by leaf and root-associated microbes. The present study evaluated the effect of the foliar application of three strains of Bacillus spp. on plant growth and fruit quality. The application of a bacilli spore preparation significantly improved leaf growth parameters such as leaf thickness and photosynthesis capacity, indicating that bacilli treatment directly promoted leaf growth. In addition, foliar treatment resulted in an improvement in the key indicators of fruit quality including water, glucose, and sucrose contents. The present results suggest that foliar spraying of beneficial bacilli is a potential treatment of wide application for the improvement of apple quality. Foliar application of bacilli preparation as effective plant growth-promoting rhizobacteria broadens the spectrum of their availability for orchard application.

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

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.1
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• pp.1-7
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• 2014

The objective of this study was to determine the effect of single and co-inoculation of plant growth promoting bacteria (PGPB) on early plant growth in Saemangeum reclaimed soil. Plant growth promoting Brevibacterium iodinum RS16 and Methylobacterium oryzae CBMB20 were inoculated on maize (Zea mays L.) and sorghum-sudangrass hybrid (Sorghum bicolor L.) grown in Saemangeum reclaimed soil. Single and co-inoculation of B. iodinum RS16 and M. oryzae CBMB20 increased plant height, dry biomass accumulation and macro-nutrient accumulation of maize and sorghum-sudangrass hybrid. M. oryzae CBMB20 treatment increased plant height in maize by 41.2% at 30 days after sowing (DAS), shoot dry weight and total dry weight compared to non-inoculated treatment. Macro-nutrient accumulation (N and P) in maize roots was significantly increased with co-inoculation treatment, K and Ca content was significantly increased at B. iodinum RS16 treatment compared to non-inoculated treatment. Macro-nutrient accumulation (P, K, Ca and Mg) in shoot was higher with M. oryzae CBMB20 treatment compared to non-inoculated treatment. In case of sorghum-sudangrass hybrid, co-inoculation treatment showed 33.7% increase in plant height compared to non-inoculated treatment at 30 DAS. M. oryzae CBMB20 treatment increased root dry weight and total dry weight, macro-nutrient accumulation in roots and N, Ca and Mg accumulation in shoot compared to non-inoculated treatment. P and K accumulation in shoot was significantly increased at co-inoculation treatment compared to non-inoculated treatment. This pot culture experiment demonstrated that single and co-inoculation of B. iodinum RS16 and M. oryzae CBMB20 increased the early growth and nutrient accumulation of maize and sorghum-sudangrass hybrid.

• Research in Plant Disease
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• v.29 no.2
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• pp.174-183
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• 2023

The limited effectiveness of current plant disease management treatments necessitates the development of new methods for controlling diseases using beneficial microbes. Demanding sustainable agriculture is increasingly highlighted as a biocontrol approach, particularly Streptomyces species known to produce a variety of antibiotic compounds and secondary metabolites. The Streptomyces globisporus SP6C4 strain and Streptomyces sp. S8 have been reported as potent antifungal agents and are gaining attention for improving crop growth in sustainable agriculture. In this study, we investigated the use of Streptomyces species formulations to enhance bacterial growth with nitrogen sources. Specifically, the addition of L-glutamic acid and L-cysteine resulted in earlier sporulation and bacterial growth in Streptomyces strains, respectively. This approach could expand the range of fermentation techniques in agriculture and be useful for controlling plant growth-promoting bacteria.

• Journal of Applied Biological Chemistry
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• v.55 no.2
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• pp.129-133
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• 2012

To exploit plant growth promoting bacteria in the roots of Miscanthus sacchariflorus, a biomass energy crop, total 64 bacteria were isolated. For the investigation of plant growth promoting effects from the isolated bacteria, production of indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activities were tested and other cultural conditions were examined. As results, 8 isolates showed plant growth promoting effects on the M. sacchariflorus and an isolate designated Agrobacterium sp. BE516 has the highest activity by enhancing the shoot elongation over 2-fold than the control. Agrobacterium sp. BE516 produced 64 ${\mu}g$ IAA per mL and showed ACC deaminase activity which is involved in the resistance to environmental stress such as high salt and drought. It could grow at low temperature in the range from 4 to $15^{\circ}C$, at pH 4.0 and at 4% NaCl. These results indicate that the Agrobacterium sp. BE516 can be useful as a bio-fertilizer for M. sacchariflorus under the stressed conditions.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.55.1-55
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• 2002

• The Plant Pathology Journal
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• v.17 no.3
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• pp.174-179
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• 2001

The plant growth-promoting Pseudomonas strains, WR8-3 (Pseudomonas fluorescens), WR9-11 (Pseudomonas sp.) and WR9-16 (P.putida), which induced resistance systematically in watermelon to gummy stem rot were investigated on their induced systemic resistance(ISR)-related characteristics. The pyoverdine production was repressed in the standard succinate medium by increasing the concentration of $\textrm{FeCL}_3$. But the iron-binding ability on chrome azurol S agar media (CAS) was observed only in the strains, WR8-3 and WR9-16. When the two strains were mutated, the resulting iron-binding siderophore-negative mutants, WR8-3m and WR 9-16m, failed to promote the growth of watermelon and to induce resistance. The strains, WR8-3 and WR 9-16, slightly inhibited the growth of Didymella bryoniae at a low concentration of $\textrm{FeCL}_3$ on Kong's medium B, but not to exert control dffect. The strain WR9-11 showed antagonism in the concentration of $\textrm{FeCL}_3$ from 0 to $1,000\mu\textrm{M}$. When the crude lipoplysaccharide of each strain was treated in the rhizosphere of watermelon, mean lesion area was similar to that of the untreated control. The strains, WR9-11 and WR9-16 produced some level of hydrogen cyanide (HCN). Salicylic acid production was not detected in all of the strains.

• Horticultural Science & Technology
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• v.35 no.1
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• pp.11-20
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• 2017

The objective of this study was to determine whether inoculation with Bacillus licheniformis MH48 as a plant growth-promoting rhizobacterium (PGPR) could promote nutrient uptake of seedlings of the ornamental plant Camellia japonica in the Saemangeum reclaimed coastal land in Korea. B. licheniformis MH48 inoculation increased total nitrogen and phosphorus content in soils by 2.2 and 20.0 fold, respectively, compared to those without bacterial inoculation. In addition, B. licheniformis MH48 produced auxin, which promoted the formation of lateral roots and root hairs, decreased production of growth-inhibiting ethylene, and alleviated salt stress. Total nitrogen and phosphorus uptake of seedlings subjected to bacterial inoculation was 2.3 and 3.6 fold higher, respectively, than the control. However, B. licheniformis MH48 inoculation had no significant effect on the growth of seedlings. Our results suggest that inoculation with B. licheniformis MH48 can be used as a PGPR bio - enhancer to stimulate fine root development, promote nutrient uptake and alleviate salt stress in ornamental plant seedlings grown in the high-salinity conditions of reclaimed coastal land.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.637-649
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• 2011

Soil microorganisms play a major role in improving soil fertility and plant health. Symbiotic arbuscular mycorrhizal fungi (AMF) form a key component of the soil microbial populations. AMF form a mutualistic association with the host plant and exert a positive influence on its growth and nutrient uptake. The establishment of mycorrhizal symbioses with the host plant can positively be influenced by plant growth promoting rhizobacteria through various mechanisms such as increased spore germination and hyphal permeability in plant roots. Though there are evidences that combined interactions between AMF and PGPR can promote the plant growth however mechanisms of these interactions are poorly understood. Better understanding of the interactions between AMF and other microorganisms is necessary for maintaining soil fertility and enhancing crop production. This paper reviews current knowledge concerning the interactions between AMF and PGPR with plants and discusses on enhanced nutrient availability, biocontrol, abiotic stress tolerance and phytoremediation in sustainable agriculture.