• The Korean Journal of Mycology
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• v.37 no.2
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• pp.181-188
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• 2009

A Gram-positive, rod-shaped bacteria named DY5 was isolated from a peat sample collected from Daeam mountain in Korea. The culture filtrate of the bacterial isolate DY5 showed a broad spectrum of antifungal activity on various crop pathogenic fungi such as Trichoderma koningii, Fusarium oxysporum, Colletotrichum gloeosporioides, Sclerotinia sclerotiorum, Rhizoctonia solani AG-1(IA) For the identification of the DY5, morphological, biochemical, API 50 CHB test, analysis of fatty acid and molecular phylogenetic approaches were performed. The DY5 was found to be a member of the genus Paenibacillus on the basis of morphological and biochemical analysis. The 16S rRNA of DY5 showed high similarity(98%) with Paenibacillus polymyxa. On the basis of these results, the DY5 was identified as Paenibacillus polymyxa. Antifungal substance of the DY5 would be mild alkaline proteine molecule. The DY5 seems to have a great potential to be a biocontrol agent against various crop pathogens.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1575-1579
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• 2012

Paenibacillus polymyxa is known to be a plant-growth-promoting rhizobacterium. The present study describes a quantitative polymerase chain reaction (qPCR) assay for the specific detection and quantitation of P. polymyxa using a primer pair based on the sequence of a membrane-fusion protein for the amplification of a 268 bp DNA fragment. This study reports that the qPCR-based method is applicable for the rapid and sensitive detection of P. polymyxa and can be used as an alternative method for agricultural soil monitoring.

• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.379-387
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• 2007

This study was conducted to investigate the pathogenicity of Paenibacillus (R) polymyxa JB 115 and single oral dose toxicity of culture broth containing (${\beta}$-glucan (CBG-JB 115) produced from P. polymyxa JB 115 in Sprague-Dawely rats of both sexes for 14 days. After oral administration of P. polymyxa JB 115 into rats, we could not find any abnormal clinical signs and variation in the body weight and temperature as compared with control group. We also investigated the acute toxicity of CBG-JB 115. As the results, there were no clinical signs and variance in the body weight and temperature related with CBG-JB 115 in comparison with the control group. From the this experiment, we could not find out any significant pathogenicity and toxicity induced by P. polymyxa JB 115 or by CBG-JB 115. Results of this study demonstrated that consumption of P. polymyxa JB 115 and its culture broth containing (${\beta}$-glucan was not associated with any obvious signs of toxicity in Sprague-Dawely rats even following consumption of large quantities.

• Korean Journal of Organic Agriculture
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• v.29 no.2
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• pp.257-273
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• 2021

Koreans consume cham-chwi (Aster scaber thunb.) as a common vegetable in a meal because of its bitter taste and rich flavor. In addition, it is the crop with the most residual pesticides detected in the last five years. Among the detected pesticides, the most common was azoxystrobin, which is a drug used primarily to prevent the leaf spot disease of A. scaber caused by Septoria sp.. We isolated the microorganisms that antifungal activity against Septoria sp.. The optimum incubation conditions (temperature, pH and growth medium) were examined for the growth of the isolates. Additionally, cellulase and protease activity and siderophore production ability were also examined. According to 16S rRNA sequencing of the isolate was affiliated to Paenibacillus polymyxa JE201. Largest inhibition zone measuring up to 9.2 mm was observed for P. polymyxa JE201 after 7 days of inoculation. P. polymyxa JE201 strain showed antifungal activity against various fungal phytopathogens Altanaria sp., Botrytis cinerea, Colletotrichum acutatum, Fusarium oxysporum, Phytophthora capsici, Ph. drechesleria, Rhizoctonia solani and Stemphylium sp.. Based on these observations, P. polymyxa. JE201 can be used as a promising biocontrol agent for preventing the leaf spot disease and other phytopathogens.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.342-348
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• 2007

In a previous study, a new antibacterial activity was found from Paenibacillus polymyxa DY1 isolated from Korean soil, which showed a good growth inhibition against various multidrug resistant enteric bacteria. Thus the effect of nutritional factors and physicochemical conditions on the growth of P. polymyxa DY1 cells and the production of antibacterial activity were evaluated in this study. For the growth of P. polymyxa DY1 cells the optimum condition reaches by incubating at $35^{\circ}C$ for 48 hours by shaking at 180 rpm in the basal medium containing 0.6% dextrose, 1.4% ammonium phosphate dibasic, 0.9% peptone, 2.4% glutamine, and 2 mM sodium molybdate with initial pH 8.0. A maximum level of antibacterial activity was obtained when P. polymyxa DY1 was incubated at $35^{\circ}C$ for 48 hours by shaking at 180 rpm in the basal medium with initial pH 8.0 containing 1% dextrose, 1.5% ammonium sulfate, 1.1% casamino acid, 1.9% aspartic acid, and 2 mM ferrous sulfate.

• KSBB Journal
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• v.23 no.1
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• pp.65-69
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• 2008

The culture broth of a ${\beta}$-glucan-producing bacterium, Paenibacillus polymyxa JB115, was confirmed to show the antibiosis against pathogenic bacteria of livestock disease. The antibacterial substance produced by P. polymyxa JB115 exhibited strong bactericidal or bacteriostatic effect on the growth of livestock pathogenic bacteria including Staphylococcus aureus, Salmonella choleraesuis, Escherichia coli and Pseudomonas aeruginosa. This antibacterial substance also showed high stabilities in broad pH range (pH 3-11) and in broad temperature range $(40-121^{\circ}C)$, which is good enough to apply spray-dry method for the formulation of culture broth. It was also found that the antibacterial substance was very stable in artificial gastric fluid and bile acid, which implies the anticipated antibacterial activity against gastrointestinal bacteria harmful for livestocks. In conclusion, the culture broth of P. polymyxa JB115 can be developed as a multifuctional feed additive containing immune-enhancing ${\beta}$-glucan as well as antibacterial agent against livestock pathogenic bacteria.

• Korean Journal of Microbiology
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• v.43 no.1
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• pp.47-53
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• 2007

The DY1 strain of Gram-positive, rod-shaped bacteria was isolated from the soil sample collected from Daeam mountain, Korea. The culture filtrate of DY1 strain showed a broad spectrum of antimicrobial activity on various pathogenic and food poisoning enteric bacterial species tested in vitro. It showed significant growth-inhibitory effect on Salmonella enterica sp., Shigella sp., pathogenic Escherichia coli, Vibrio cholerae, Vibrio parahemolyticus, and Yersinia enterocolitica. For the identification of the DY1 strain, morphological, biochemical and molecular phylogenetic approaches were performed. The DY1 strain was found to be a member of the genus Paenibacillus on the basis of morphological and biochemical analyses. The 16S rDNA of DY1 showed the highest pairwise identity with Paenibacillus polymyxa with 99.79% (1,413 bp/1,416 bp). The antimicrobial entity from DY1 looked different from preciously reported ones and seems to have a great potential to be further studied as a candidate of new antibiotics to control multi-drug resistant pathogens.

• The Plant Pathology Journal
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• v.24 no.3
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• pp.352-356
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• 2008

Root discs of 4-year-old ginseng, Panax ginseng C. A. Meyer, were inoculated with the higher($10^8$ colonyforming units(CFU)/ml) and lower($10^6\;or\;10^5$ CFU/ml) initial inoculum levels of a plant-growth promoting rhizobacterium(PGPR), Paenibacillus polymyxa GBR-1 to examine rot symptom development and bacterial population changes on the root discs. At the higher inoculum level, brown rot symptoms developed and expanded on the whole root discs in which the bacterial population increased continuously up to 4 days after inoculation. In light and electron microscopy, ginseng root cells on the inoculation sites were extensively decayed, which were characterized by dissolved cell walls and destructed cytoplasmic contents. However, no rot symptoms were developed and the bacterial population increased only during the initial two days of inoculation at the lower inoculum level($10^6$ CFU/ml) of P. polymyxa GBR-1. At the lower inoculum level($10^5$ CFU/ml), boundary layers with parallel periclinal cell divisions, structurally similar to wound periderm, were formed internal to the inoculation sites, beneath which the cells were intact containing numerous normal-looking starch granules and no disorganized cell organelles, suggesting that these structural features may be related to the suppression of symptom development, a histological defense mechanism.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.354-361
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• 2018

This study was carried out to isolate soil bacteria with antimicrobial activity and evaluate antimicrobial substances produced by isolated bacteria. Among many isolates Bacillus subtilis DS660 and Paenibacillus polymyxa DS842 showed high antimicrobial activities against 6 species of microbial residents on human skin and 3 species of pathogenic bacteria. DS660 and DS842 showed 15.3~26.8 and 11.3~27.5 mm of inhibition zone diameter, respectively on nutrient agar medium against most target bacteria and fungi. DS660 and DS842 produced $57{\pm}8$ and $170{\pm}15{\mu}mol/ml$ of siderophore, respectively as an antimicrobial substance. Analysis of ethyl acetate extract of culture supernatants of DS660 and DS842 suggested production of glycolipid biosurfactant which reduced surface tension of culture supernatant of DS660 and DS842 from 60.0 to 40.3 and 30.3 mN/m, respectively. DS660 and DS842 also showed $169.2{\pm}9.9$ and $357.2{\pm}13.7nmol/min/mg$ protein of ${\beta}-1,3$-glucanase activity, respectively, and hydrolyzed cell wall components of 3 bacterial species. These results suggest that B. subtilis DS660 and P. polymyxa DS842 may be utilized as an environment-friendly biocontrol agent against some skin microbes and pathogenic bacteria.

• Mycobiology
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• v.42 no.2
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• pp.158-166
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• 2014

In this study, bacterial strains were isolated from soils from 30 locations of Samcheok, Gangwon province. Of the isolated strains, seven showed potential plant growth promoting and antagonistic activities. Based on cultural and morphological characterization, and 16S rRNA gene sequencing, these strains were identified as Paenibacillus species. All seven strains produced ammonia, cellulase, hydrocyanic acid, indole-3-acetic acid, protease, phosphatase, and siderophores. They also inhibited the mycelial growth of Fusarium oxysporum f. sp. radicis-lycopersici in vitro. The seven Paenibacillus strains enhanced a range of growth parameters in tomato plants under greenhouse conditions, in comparison with non-inoculated control plants. Notably, treatment of tomato plants with one identified strain, P. polymyxa SC09-21, resulted in 80.0% suppression of fusarium crown and root rot under greenhouse conditions. The plant growth promoting and antifungal activity of P. polymyxa SC09-21 identified in this study highlight its potential suitability as a bioinoculant.