• Journal of Life Science
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• v.17 no.11
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• pp.1562-1570
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• 2007

This experiment was conducted to develop fertilizer which promotes plant growth as well as suppressing pathogenic fungi. The fertilizer was made from the mixture of Ju-Back (Korean rice wine cake) and indigenous rhizosphere-bacterium. The main ingredients of Ju-Back were investigated as 6.04% total nitrogen, 42.59% total carbohydrate, 1.01% available phosphate, 73.42% organic matter, 7.72% potassium oxide, 1.35% calcium oxide, 0.53% magnesium oxide. The enzyme activities of Ju-Back were estimated to be 980 units/g for ${\alpha}-amylase$, 300 units/g for glucoamylase, and 1800 units/g for acid pretense. Indigenous rhizosphere bacteria which produced antifungal agent were isolated from soil, and was selected KMU-13 strain which can antagonize against various plant pathogenic fungi (Botrytis cinerea KACC 40573, Sclerotinia sclerotiorum KACC 41065, Fusairum oxysporum KACC 40052, Pythium aphanidermatum KACC 40156, Phytophthora capsici KACC 40476 and Glomerella cingulata KACC 40299). KMU-13 strain was identified as Bacillus subtilis KMU-13 by biochemical and 16s rDNA analysis. The organic fertilizer was made as prototype which was composed 20% Ju-Back, 70% carrier, 9.7% microorganism cultivated solution, 0.3% trace-element. We also investigated an application of fertilizer using Ju-Back for cultivating lettuce (Lactuca sativar) which were grown in three soil conditions that had chemical fertilizer, barnyard manure, lime power, urea, potassium chloride and superphosphate as a control, the whole quantity (80 kg/10a) of posted fertilizer with the control and the half quantity (40 kg/10a) with the control. The growth characteristics were examined and analysed with several weeks interval from 3 weeks to 8 weeks on head length (cm), head width (cm/head), number of leaf and fresh weight (g/plant). The results are summarized as follows. The head width and fresh weight of lettuce were the highest at posted fertilizer 1 (whole quantity) was applied chemical, organic matter (Ju-Back) and carrier. The head length was the highest at posted fertilizer 2 (whole quantity) was applied Ju-Back only.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.16-25
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• 2009

Cauliflower mushroom (Sparassis crispa) is recently recognized as a new edible and/or medicinal mushroom cultivated with conifers. By the way, the mushroom is notorious as a brown-rot fungus that causes a buttrot of larch. So, there should be a careful consideration to apply the mushroom cultivation in coniferous stand. This study was conducted to clarify the seriousness of heartwood decay on conifers such as larch by cauliflower mushroom with surveying the mushroom producing environment and to examine whether the cultivation of cauliflower mushroom produce any problem in conifer stands or not. The mushroom occurred in various coniferous stands such as Larix kaempferi, Pinus koraiensis, P. densiflora and Abies holophylla on fertile soils with adequate moisture. Soil texture of the mushroom producing site was comparatively fine compared to general forest soils; sandy loam, loam and silty loam. Soil pH ranged from 4.6 to 5.2, and organic matter contents were 4~11%, which showed relatively wide range. We could find S. crispa by a DNA technique from the wood that seemed to have no heartwood decay by naked eyes. The damaged wood showed 30% higher moisture contents than that of sound wood, while the compressive strength was 30% lowered down compared to that of sound wood. The fungus may invade conifers through the scars occurred on roots or stems, in this case spore dispersion of the mushroom takes a great role. Thus, we concluded that forest tending activities need to be applied with considering the invasion of S. crispa, and cultivation of cauliflower mushroom in forest should be attempted very carefully. By the way, we also infer that conifer stands can be nurtured without heartwood decay by S. crispa if the stand be managed in good aeration conditions by proper silvicultural practices such as sanitary thinning.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.2
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• pp.106-111
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• 2018

This study was conducted to investigate the relationship between changes of rumen microflora and bloat in Jersey cow. Jersey cows (control age: 42 months, control weight: 558kg; treatment age: 29 months, treatment weight 507kg) were fed on the basis of dairy feeding management at dairy science division in National Institute of Animal Science. The change of microbial population in rumen was analyzed by using next generation sequencing (NGS) technologies due to metabolic disease. The diversity of Ruminococcus bromii, Bifidobacterium pseudolongum, Bifidobacterium merycicum and Butyrivibrio fibrisolvens known as major starch fermenting bacteria was increased more than 36-fold in bloated Jersey, while cellulolytic bacteria community such as Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens was increased more than 12-fold in non-bloated Jersey. The proportion of bacteroidetes and firmicutes was 33.4% and 39.6% in non-bloated Jersey's rumen, while bacteroidetes and firmicutes were 24.9% and 55.1% in bloated Jersey's. In conclusion, the change of rumen microbial community, in particular the increase in starch fermenting bacteria, might have an effect to occur the bloat in Jersey cow.

• Journal of Life Science
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• v.24 no.4
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• pp.461-466
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• 2014

Three plant species, Aster sphathulifolius, Sedum oryzifolium, and Lysimachia mauritiana, native to the Dokdo Islands in South Korea, were examined for rhizosphere microorganisms by using 16S rDNA sequences. Nine species of rhizosphere microorganisms were isolated from the three native plant species, respectively. Phylogenetic analysis showed that the microorganisms could be classified into 19 species belonging to four phyla (Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria), and the characteristics of the microbes were confirmed. Rhizosphere microorganisms from the six orders (Bacillales, Corynebacteriales, Flavobacteriales, Micrococcales, Oceanospirillales, and Rhodobacterales) were isolated from S. oryzifolium. From L. mauritiana, microbes belonging to the seven orders (Bacillales, Flavobacteriales, Micrococcales, Oceanospirillales, Rhizobiales, and Rhodobacterales) were isolated. From A. sphathulifolius, the six orders of rhizosphere microorganisms (Alteromonadales, Bacillales, Corynebacteriales, Flavobacteriales, Micrococcales, and Rhizobiales) were isolated. These data showed that Actinobacteria and Proteobacteria were the dominant phyla for the rhizosphere of all three plants. To confirm the bacterial diversity in rhizospheres, Shannon's diversity index (H') was used at the genus level. In these data, the rhizosphere from S. oryzifolium and L. mauritiana had more diverse bacteria compared to that from A. sphathulifolius.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.342-347
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• 2004

A bacterial strain YC4963 with antifungal activity against Colletotrichum orbiculare, a causal organism of cucumber anthracnose was isolated from the rhizosphere soil of Siegesbeckia pubescens Makino in Korea. Based on physiological and biochemical characteristics and 16S ribosomal DNA sequence analysis, the bac­terial strain was identified as Pseudomonas aurantiaca. The bacteria also inhibited mycelial growth of several plant fungal pathogens such as Botrytis cinerea, Fusarium oxysporum and Rhizoctonia solani on PDA and 0.1 TSA media. The antifungal activity was found from the culture filtrate of this isolate and the active compound was quantitatively bound to XAD adsorption resin. The antibiotic compound was purified and identified as phenazine-l-carboxylic acid on the basis of combined spectral and chemical analyses data. This is the first report on the production of phenazine-l-carboxylic acid by Pseudomonas aurantiaca.

• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.55-61
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• 2011

Forty yeast strains isolated from soils taken from different locations in Egypt were tested for their P-solubilizing activities on the basis of analyzing the clear zone around colonies growing on a tricalcium phosphate medium after incubation for 5 days at $25^{\circ}C$, denoted as the solubilization index (SI). Nine isolates that exhibited P-solubilization potential with an SI ranging from 1.19 to 2.76 were genetically characterized as five yeasts belonging to the genus Saccharomyces cerevisiae and four non-Saccharomyces, based on a PCR analysis of the ITS1-26S region amplied by SC1/SC2 species-specific primers. The highest P-solubilization efficiency was demonstrated by isolate PSY- 4, which was identified as Saccharomyces cerevisiae by a sequence analysis of the variable D1/D2 domain of the 26S rDNA. The effects of single and mixed inoculations with yeast PSY-4 and Bacillus polymyxa on the P-uptake and growth of corn were tested in a greenhouse experiment using different levels of a phosphorus chemical fertilizer (50, 100, and 200 kg/ha super phosphate 15.5% $P_2O_5$). The results showed that inoculating the corn with yeast PSY-4 or B. polymyxa caused significant increases in the shoot and root dry weights and P-uptake in the shoots and roots. The P-fertilization level also had a significant influence on the shoot and root dry weights and P-uptake in the shoots and roots when increasing the P-level from 50 up to 200 kg/ha. Dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 200 kg/ha gave higher values for the shoot and root dry weights and P-uptake in the shoots and roots, yet these increases were nonsignificant when compared with dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 100 kg/ha. The best increases were obtained from dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 100 kg/ha, which induced the following percentage increases in the shoot and root dry weights, and P-uptake in the shoots and roots; 16.22%, 46.92%, 10.09%, and 31.07%, respectively, when compared with the uninoculated control (fertilized with 100 kg/ha).

• The Korean Journal of Mycology
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• v.41 no.4
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• pp.218-224
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• 2013

Of 1,100 yeast strains which were isolated from various Korean fermented foods, screened for phosphate solubilization, five strains showed the ability to solubilize tricalcium phosphate. The 26S rDNA domain D1-D2 sequence analysis revealed the identification of strain Y393 and Y524 as Pichia anomala (99.8 and 100% identity, respectively), Y669 as Pichia farinosa (100% identity), Y901 as Candida versatilis (100% identity), and Y1101 as Pichia subpelliculosa (100% identity). All the phosphate solubilizing strains showed mesophilic characteristics. The temperature range for growth of 4 strains was $20{\sim}35^{\circ}C$ and P. farinosa Y669 was able to grow up to $45^{\circ}C$. The strain C. versatilis Y907 was able to grow at pH range of 5.0~6.0 and showed halophilic characteristics with tolerance to 15% of NaCl concentration. The Phosphate solubilizing yeast strains were survived well in bed soil for 8 weeks which were maintained densities of $10^7{\sim}10^8$ cfu/g. The highest phosphate solubilizing activity was observed in P. subpelliculosa Y1101. It solubilized 697.2 ug/mL of phosphorus from tricalcium phosphate with decrease in pH from 6.8 to 4.37 after 11 days of inoculation.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.437-441
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• 2019

Verticillium wilt disease is caused by a fungal plant pathogen Verticillium dahliae, which attacks commercial crops such as chrysanthemum. The conventional methods so far used to identify this fungal pathogen require high expertise and are time-consuming. Therefore, in this study, we developed an assay for the rapid and specific detection of V. dahliae infection using loop-mediated isothermal amplification (LAMP) method. For this assay, four primers for LAMP were designed for targeting cellulose-growth-specific protein partial mRNA gene in Verticillium dahliae. Under standard condition, the optimum reaction temperature for amplification is around 60 ℃ within 60 minutes. This LAMP assay was designed to amplify only present in V. dahliae. When this LAMP assay applied to the DNAs for four other soil-borne fungi and host plants, no amplification was detected. Therefore, this LAMP assay we developed for V. dahliae is expected to do detection at the early stage of its infection. The fast and reliable detection method will allow us to develop effective management system to monitor and control infection of this pathogen in chrysanthemum plant.

• Research in Plant Disease
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• v.21 no.1
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• pp.36-39
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• 2015

In June 2012 and 2013, a destructive stem rot symptoms of Ligularia fischeri occurred sporadically in Hoengseong-gun and Pyeongchang-gun Gangwon-do, Korea. The typical symptom included water-soaking on the main stem, rotting, wilting and blighting, which eventually leads to death of the plant. White mycelial mats were spread over lesions and brown sclerotia were formed on stems and near soil surface. The sclerotia were white to brown, spherical or irregular, 1-3 mm in size on potato dextrose agar (PDA), The optimum temperature range of hyphal growth was $25-30^{\circ}C$ and the hyphal diameter was $4-10{\mu}m$. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. The resulting sequence of 695 bp was deposited in GenBank. A BLAST search revealed that sequences of the this isolates showed >99% identity with those of Sclerotium rolfsii. On the basis of the morphological characteristics and phylogenetic analyses of molecular markers ITS rDNA, the fungi were identified as S. rolfsii. A pathogenicity test was carried out to fulfill Koch's postulates. To our knowledge, this is the first report of S. rolfsii on Ligularia fischeri in Korea.

• The Korean Journal of Pesticide Science
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• v.19 no.2
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• pp.141-150
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• 2015

Thirty-two actinomycetes isolates from Korean forest soil were screened for their nematicidal and reproduction suppression activity against pine wood nematode (PWN) which is widely spread in Korea. Culture filterates of 21 isolates showed more than 90% mortality at 2-fold concentration. Among them, AM210, SG16, YD116 and YD315 were more effective than others on reproduction of PWN. The YD116 isolate was identified as Streptomyces atratus by morphological and 16S rDNA analyses. Hydrazine hydrate, similar to hydrazidomycin which has cytotoxicity among substances from S. atratus against PWN, was tested for its nematicidal activity. Ten ppm of the hydrate showed 60.8% mortality. Additional studies are needed for practical use of the S. atratus YD116 isolate.