• Journal of Mushroom
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• v.13 no.4
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• pp.275-281
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• 2015

An auxin-producing bacteria (A-1) was isolated from soils of Oyster mushroom farmhouse in Daejeon city, South Korea. The strain A-1 was classified as a novel strain of Ochrobactrum anthropi based on a chemotaxanomic and phylogenetic analyses. The isolate was confirmed to produce indole-3-acetic acid (IAA), one of auxin hormones, by TLC and HPLC analyses. The maximum concentration of IAA, $5.6mg\;L^{-1}$ was detected from the culture broth of O. anthropi A-1 incubated for 24 h at $35^{\circ}C$ in R2A broth containing 0.1% L-tryptophan. To investigate the growth-promoting effects to the crops, the culture broth of O. anthropi A-1 was inoculated to water cultures and seed pots of mung bean as well as lettuce. In consequence, the adventitious root induction and root growth of mung bean and lettuce were 2.7 and 1.4 times higher than those of the non-inoculated, respectively.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.172-176
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• 2004

Bacterial isolates TRL2-3 and TRK2-2 showing anti-fungal activity in vitro test against some plant pathogens were identified as Pseudomonas putida and Micrococcus luteus, respectively. Pre-treatment with both bacterial isolates at the concentration 1.0$\times$ $10^7$ and $10^6$cfu/ml in the rhizosphere could trigger induced systemic resistance in the aerial part of cucumber plants against anthracnose caused by Colletotrichum orbiculare. However, the pre-treatment with the higher concentration at 1.0 $\times$ $10^8$ cfu/ml of both isolates could not induce resistance after challenge inoculation with C. orbiculare. As a positive control, the treatment with DL-3 amino butyric acid caused a remarkable reduction of disease severity whereas the lesions on the leaves of untreated plants developed apparently after the fungal inoculation. From these results, it was recomended that disease control using both bacterial isolates inducing systemic resistance in the field where chemical application is forbid.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10b
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• pp.14-14
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• 2003

The aim of the present study isto assess the importance of siderophore producing rhizosphere bacteria on the growth of Brassica junceaunder chromium stress. Pseudomonassp. (A4) produced an iron chelating substance siderophores in iron deficient medium. Under chromium stress condition Pseudomonassp. (A4) markedly increased the root and shoot length and also biomass of Brassica juncea as compared to Pseudomonas sp. (A3). This plant growth promotion has been related to the microbial production of siderophore.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10a
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• pp.20-29
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• 2003

The aim of the present study isto assess the importance of siderophore producing rhizosphere bacteria on the growth of Brassica junceaunder chromium stress. Pseudomonassp. (A4) produced an iron chelating substance siderophores in iron deficient medium. under chromium stress condition Pseudomonassp. (A4) markedly increased the root and shoot length and also biomass of Brassica juncea as compared to Pseudomonas sp. (A3). This plant growth promotion has been related to the microbial production of siderophore.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1250-1258
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• 2009

Bacillus spp., as a type of plant growth-promoting rhizobacteria (PGPR), were studied with regards promoting plant growth and inducing plant systemic resistance. The results of greenhouse experiments with tobacco plants demonstrated that treatment with the Bacillus spp. significantly enhanced the plant height and fresh weight, while clearly lowering the disease severity rating of the tobacco mosaic virus (TMV) at 28 days post-inoculation (dpi). The TMV accumulation in the young non-inoculated leaves was remarkably lower for all the plants treated with the Bacillus spp. An RT-PCR analysis of the signaling regulatory genes Coil and NPR1, and defense genes PR-1a and PR-1b, in the tobacco treated with the Bacillus spp. revealed an association with enhancing the systemic resistance of tobacco to TMV. A further analysis of two expansin genes that regulate plant cell growth, NtEXP2 and NtEXP6, also verified a concomitant growth promotion in the roots and leaves of the tobacco responding to the Bacillus spp.

• Korean Journal of Organic Agriculture
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• v.26 no.3
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• pp.463-475
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• 2018

Salinity and extreme temperature stresses affect growth and productivity of crops negatively. Beneficial bacteria, including plant growth-promoting rhizobacteria (PGPR) induce growth promotion and tolerance of plants under abiotic stress conditions. In the present study, 20 strains were selected from 1944 isolated bacteria based on three plant growth-promoting (PGP) traits-aminocyclopropane-1-carboxylate deaminase activity, phosphate solubilization, indole-3-acetic acid production, and growth ability under salinity and extreme temperature stress conditions. Seven among the 20 strains were selected based on growth-promoting effects on plants under saline or temperature stresses in tomato plants. It was expected that the seven strains could induce tolerance of tomato plants under salinity or extreme temperature stresses, which implies that these seven strains can act as potential inducers of multiple stresses tolerance in tomato plants.

• Journal of Mushroom
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• v.15 no.1
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• pp.8-13
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• 2017

An auxin-producing bacterial strain, designated 4-3, was isolated from waste button mushroom compost in Boryeong-si, Chungnam. The strain 4-3 was classified as a novel strain of Leucobacter tardus, based on chemotaxonomic and phylogenetic analyses. TLC and HPLC the isolated L. tardus strain 4-3 produced indole-3-acetic acid (IAA), the auxin. Maximum IAA productionof $94.3mg\;L^{-1}$ was detected for bacteria cultured in R2A medium with 0.1% l-tryptophan, incubated for 24 h at $35^{\circ}C$. Negative correlationwas observed between IAA production and pH of the culture medium, indicating that the increase inIAA caused acidification ofthe medium. The effect of supplementation with varying concentrations of l-tryptophan, a known precursor of IAA, was also assessed. production was maximal at 0.1% l, but decreased at lconcentrations above 0.2%. To investigate the plant growth-promoting effects of the bacterium, L. tardus strain 4-3 culture broth was used to inoculate water cultures and seed pots of mung bean. We found thatadventitious root induction and root growth were 2.2-times higher in thethan in the non-inoculated plants.

• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.556-566
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• 2011

A total of 31 Acinetobacter isolates were obtained from the rhizosphere of Pennisetum glaucum and evaluated for their plant-growth-promoting traits. Two isolates, namely Acinetobacter sp. PUCM1007 and A. baumannii PUCM1029, produced indole acetic acid (10-13 ${\mu}g$/ml). A total of 26 and 27 isolates solubilized phosphates and zinc oxide, respectively. Among the mineral-solubilizing strains, A. calcoaceticus PUCM1006 solubilized phosphate most efficiently (84 mg/ml), whereas zinc oxide was solubilized by A. calcoaceticus PUCM1025 at the highest solubilization efficiency of 918%. All the Acinetobacter isolates, except PUCM1010, produced siderophores. The highest siderophore production (85.0 siderophore units) was exhibited by A. calcoaceticus PUCM1016. Strains PUCM1001 and PUCM1019 (both A. calcoaceticus) and PUCM1022 (Acinetobacter sp.) produced both hydroxamate-and catechol-type siderophores, whereas all the other strains only produced catechol-type siderophores. In vitro inhibition of Fusarium oxysporum under iron-limited conditions was demonstrated by the siderophore-producing Acinetobacter strains, where PUCM1018 was the most potent inhibitor of the fungal phytopathogen. Acinetobacter sp. PUCM1022 significantly enhanced the shoot height, root length, and root dry weights of pearl millet seedlings in pot experiments when compared with controls, underscoring the plant-growth-promoting potential of these isolates.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.105.1-105
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• 2003

The Plant growth Promoting rhizobacteria (PGPR), Pseudomonas sp. (A3) and Bacillus sp. (AT33) were isolated from the rhizosphere of Amaranthus blitum collected from soil contaminated with chromium. Both bacterial strains quantitatively reduced hexavalent chromium to trivalent chromium. Pseudomonas sp. broughter greater conversion of Cr6+ in the medium (100％) as compared to Bacillus sp.(62％). Phaseolus mungo seeds inoculated with Pseudomonas sp. or Bacillus sp. were grown under different concentration of chromium. The monitored parameters included elongation of shoot and root, fresh weight, dry weight and concentration of chromium in the shoot and root systems. As compared to non inoculated seedlings those inoculated with A3 and AT33 exhibited better growth.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10b
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• pp.57-57
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• 2003

The plant growth promoting rhizobacteria (PGPR), Pseudomonas sp. (A3) and Bacillus sp. (AT33) were isolated from the rhizosphere of Amaranthus blitum collected from soil contaminated with chromium. Bothbacterial strains quantitatively reduced hexavalent chromium to trivalent chromium. Pseudomonas sp. broughter greater conversion of Cr6+ in the medium (100%) as compared to Bacillus sp.(62%). Phaseolus mungo seeds inoculated with Pseudomonas sp. or Bacillus sp. were grown under different concentration of chromium. The monitoredparameters included elongation of shoot and root, fresh weight, dry weight and concentration of chromium in the shoot and root systems. As compared to non inoculated seedlings those inoculated with A3 and AT33 exhibited better growth.