• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2002년도 총회 및 추계학술발표회
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• pp.51.1-51
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• 2002

• 한국미생물·생명공학회지
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• 제51권3호
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• pp.303-305
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• 2023

In this study, we report the complete genome sequence of Priestia megaterium strain HyangYak-01, which was isolated from the rhizosphere soil of Centella asiatica. The genome consists of 5,086,279 bp of sequences with 38.2 percent GC content and 5,111 coding genes. The genome contains several important genes related to plant growth-promoting activities, which were also confirmed with in vitro media assays.

• Journal of Microbiology and Biotechnology
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• 제17권8호
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• pp.1300-1307
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• 2007

This study assessed the possible role of different traits in selected plant growth-promoting rhizobacteria (PGPR) for improving wheat growth and yield under natural conditions. Rhizobacteria exhibiting 1-aminocyclopropane-1-carboxylate (ACC)-deaminase activity were isolated and screened for their growth-promoting activity in wheat under axenic conditions. Five isolates belonging to Pseudomonas and one Burkholderia caryophylli isolate that showed promising performances under axenic conditions were selected and characterized for in vitro ACC-deaminase activity, chitinase activity, auxin production, P solubilization, and root colonization. These isolates were then used as inocula for wheat cultivated under natural conditions in pot and/or field trials. Significant increases in root elongation, root weight, tillers per pot, 1,000-grain weight, and grain and straw yields were observed in response to inoculation with PGPR in the pot trials. Inoculation with these PGPR was also effective under field conditions and increased the wheat growth and yield significantly. However, the efficacy of the strains was inconsistent under the axenic, pot, and field conditions. Pseudomonas fluorescens ($ACC_{50}$), which exhibited a relatively high in vitro ACC-deaminase activity, chitinase activity, auxin production, and P solubilization and more intensive root colonization, was the most efficient isolate under the field conditions. Therefore, these results demonstrated that ACC-deaminase activity is an efficient parameter for the selection of promising PGPR under axenic conditions. However, additional traits of PGPR, including auxin production, chitinase activity, P solubilization, and root colonization, are also important for selecting PGPR as biofertilizers.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.403-412
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• 2021

본 연구에서는 토양 및 근권에 존재하는 Bacillus 속의 식물 생장 촉진 활성, 식물 병원성 곰팡이의 생장 억제활성, 미네랄 가용화능 및 세포 외 효소활성을 확인해 보고자 하였다. 식물 병원성 곰팡이에 대한 항진균 활성에서 DDP257은 10종의 병원성 곰팡이에서 항진균 활성이 모두 나타났다. 식물 생장 촉진 인자인 indole-3-acetic acid 생성능에서는 ANG20이 70.97 ㎍/ml로 가장 높게 나타났다. 추가적으로 1-aminocyclopropane-1-carboxylate deaminase 생성능 조사에서는 총 10종에서 생성능을 확인하였고, 질소 고정능과 siderophore 생성능 조사에서는 대부분의 분리균주에서 활성을 확인하였다. 이후 분리된 균주에 대하여 phosphate, calcite, zinc과 같은 미네랄 가용화능을 확인하였으며 세포외 효소활성에서도 대부분의 효소에서 활성이 나타났다. 특히 alkaline phosphatase, esterase (C4), acid phosphatase, naphtol-AS-BI-phosphohydrolase에서 선별된 균주 모두 유사한 활성을 보였다. 이는 Bacillus 속이 다양한 유기물과 항생물질 및 세포 외 효소를 분비함으로써 이러한 결과가 나타난 것으로 판단된다. 따라서, 본 연구 결과를 통해 토양의 환경 개선에 기여하는 균주를 활용하여 미생물 제제로써의 가능성을 제시한다.

• 한국식물병리학회지
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• 제14권1호
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• pp.13-18
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• 1998

The use of bioluminescence as a sensitive marker for the detection of Pseudomnas sp. in the rhizosphere was investigated. Transposon Tn4431 which contains a promoterless luciferase operon and tetracycline resistant gene was used. This transposon, present on a suicide vector (pUCD623) in E. coli HB101, was mated with spontaneous rifampicin mutant of Pseudomonas fluorescens B16, a plant growth promoting rhizobacteria (PGPR), and then rifampicin and tetracycline resistant survivors were isolated. Twenty tow mutants wer isolated from the conjugants between E. coli HB101 and P. fluorescens B16. One of these, B16::Tn4431 (L22) recombinant which glowed brightly in the dark was selected for analysis. The cucumber seeds inoculated with L22 were grown in moisten two layers of filter paper and nonsterile soil contained in half cut PVC pipe. The roots were removed from the filter paper and PVC pipe, then placed on the 1/2 LB media plates. The plates were incubated at room temperature for 16 hr. L22 could successfully be detected in the rhizoplane by using the ordinary negative camera film (ASA100-400) with 30 minutes exposure under dark condition. The root colonizing ability and the plant growth promoting effect of L22 were not reduced compared to the untreated bacteria and wild type. L22 was superior to will type.

• 한국유기농업학회지
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• 제5권2호
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• pp.105-115
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• 1997

This experiment was conducted to clarify the plant growth promoting effect of compost supplemented with cultured solution of photosynthetic bacteria(Rhodopseudomonas capsulatus) before sowing on the early growth of plug seedling of tomato and to evaluate the optimum concentration of bacterialization. Bacterializing concentrations(v/w) to the compost were 2%, 3.3%, 10%, 20% and 50%, respectively. Plant growth in terms of plant height, stem diameter, leaf area, total fresh and dry weight were promoted by the bacterialization of photosynthetic bacteria. Especially, in the plots supplemented with 10 to 20% the early growth was promoted markedly over 2 times. Compositions of photosynthetic bacteria consisted of crude protein 60.7%, soluble carbohydrates 20.1%, crude fat 7.6%, crude fiber 3.2% and crude ash 4.8, respectively.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2006년도 제47회 학술심포지움 및 추계국제학술대회
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• pp.50.1-50.1
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• 2006

• The Plant Pathology Journal
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• 제33권2호
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• pp.170-183
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• 2017

Bacterial fruit blotch (BFB), which is caused by Acidovorax citrulli, is a serious threat to watermelon growers around the world. The present study was conducted to screen effective rhizobacterial isolates against 35 different A. citrulli isolates and determine their efficacy on BFB and growth parameters of watermelon. Two rhizobacterial isolates viz. Paenibacillus polymyxa (SN-22), Sinomonas atrocyanea (NSB-27) showed high inhibitory activity in the preliminary screening and were further evaluated for their effect on BFB and growth parameters of three different watermelon varieties under greenhouse conditions. The greenhouse experiment result revealed that SN-22 and NSB-27 significantly reduced BFB and had significant stimulatory effect on total chlorophyll content, plant height, total fresh weight and total dry weight compared to uninoculated plants across the tested three watermelon varieties. Analysis of the 16S ribosomal RNA (rRNA) sequences revealed that strains SN-22 belong to P. polymyxa and NSB-27 to S. atrocyanea with the bootstrap value of 99% and 98%, respectively. The isolates SN-22 and NSB-27 were tested for antagonistic and PGP traits. The result showed that the tested isolates produced siderophore, hydrolytic enzymes (protease and cellulose), chitinase, starch hydrolytic enzymes and they showed phosphate as well as zinc solubilizing capacity. This is the first report of P. polymyxa (SN-22) and S. atrocyanea (NSB-27) as biocontrol-plant growth promoting rhizobacteria on watermelon.

• Journal of Microbiology and Biotechnology
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• 제21권8호
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• pp.777-790
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• 2011

To elucidate the biodiversity of plant growth-promoting rhizobacteria (PGPR) in Korea, 7,638 bacteria isolated from the rhizosphere of plant species growing in many different regions were screened. A large number of PGPR were identified by testing the ability of each isolate to promote the growth of cucumber seedlings. After redundant rhizobacteria were removed via amplified rDNA restriction analysis, 90 strains were finally selected as PGPR. On the basis of 16S ribosomal RNA sequences, 68 Gram-positive (76%) and 22 Gram-negative (24%) isolates were assigned to 21 genera and 47 species. Of these genera, Bacillus (32 species) made up the largest complement, followed by Paenibacillus (19) and Pseudomonas (11). Phylogenetic analysis showed that most of the Grampositive PGPR fell into two categories: low- and high- G+C (Actinobacteria) strains. The Gram-negative PGPR were distributed in three categories: ${\alpha}$-proteobacteria, ${\beta}$- proteobacteria, and ${\gamma}$-proteobacteria. To our knowledge, this is the largest screening study designed to isolate diverse PGPR. The enlarged understanding of PGPR genetic diversity provided herein will expand the knowledge base regarding beneficial plant-microbe interactions. The outcome of this research may have a practical effect on crop production methodologies.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2010년도 정기총회 및 추계학술발표회
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• pp.18-18
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• 2010

Molecular insights on the role of plant growth promoting rhizobacteria (PGPR) in potato tuberization are reported in the present study. The PGPRwere isolated from the soil collected from potato fields of Highland Agricultural Research Centre, Pyeongchang, Korea and they were identified to the genus level based on the 16S rRNA sequence analysis. These PGPR were heat-killed, filtered and the filtrates were addedindividually at a concentration of $10^7\;cfu\;mL^{-1}$ in MS (Murashige and Skoog's) medium supplemented with 7% (w/v) sucrose to study their influence on in vitro potato tuberization. Tuber initiation occurred early in untreated control, while tuber growth was pronounced in case of PGPR treatments. The control explants showed tuber formation as a result of sub-apical swelling of stolons while several sessile tubers formed directly in the axils of nodal cuttings in case of PGPR treatments, which is an indication of strong induction for tuberization. Theexplants cultured on MS medium supplemented with bacterial isolate 6 (Bacillus firmus strain 40) showed highest average tuber yield (Ca. 12.56 g per treatment) after 30 days of culture, which was 3 folds increase over the untreated control. A significant increase in lipoxygenase (LOX1) mRNA expression and activity of LOX enzyme were also detected in the tubers induced on PGPR treatments as compared to untreated control. This LOX expression level correlated with increased tuber growth and tuber yield. Further studies focused on the role of bacteria cell wall components, growth regulators and signal molecules released by PGPR are under investigation to elicit clues for PGPR-mediated signal pathway controlling potato tuberization.