• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.866-871
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• 2011

An auxin-producing bacteria (3YN11-02) was isolated from waste mushroom bed from Agaricus bisporus of Chungnam Buyeo-Gun area. The strain 3YN11-02 was identified as a novel species belongs to Rahnella aquatica by a chemotaxanomic and phylogenetic nalysis. The isolate was confirmed to produce indole-3-acetic acid (IAA) which is one of auxin hormone by TLC and HPLC analysis. When the concentration of IAA was assessed by performing HPLC quantity analysis, the maximal $290mg\;L^{-1}$ of IAA detected in ether fraction extracted from the culture filtrate which was cultured in R2A broth containing 0.1% tryptophan for 24 h at $35^{\circ}C$. The molecular weight of the main peak obtained by LC-mass analysis was correspondent well to 175, that of IAA. To investigate the growth promoting effect of crop, when the culture broth of R. aquatica 3YN11-02 was infected onto water culture and seed pot of mung bean, the adventitious root induction and root growth of mung bean were 2.0 times higher than control.

• Korean journal of applied entomology
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• v.38 no.1
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• pp.41-46
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• 1999

This study was carried out to investigate the seasonal and regional occurrence and development of major pest flies on the oyster mushroom. The survey was performed in the oyster mushroom houses located at 16 places, selected randomly throughout South Korea from July to August and from October to November in 1997. The six species of flies were found including three pest species from Sciaridae, Cecidomyiidae and Scatopsidae flies. The pattern of occurrence was somewhat dissimilar depending on the survey periods and regions. Among these, the most serious and abundant pest, Lycoriella mali (Diptera: Sciaridae), occurred year around at the regions surveyed. In this study, Coboldia fuscipes (Diptera: Scatopsidae) was confinned as a mushroom pest. Its larvae damaged the mycelium, and occurred usually in summer from July to August. The paedogenetic Mycophila sp. (Diptera: Cecidomyiidae) was found abundantly on the oyster mushroom bed, and caused a severe damage in fall from October to November.

• Journal of Mushroom
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• v.11 no.2
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• pp.53-62
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• 2013

A total of 35 phosphate solubilizing bacterial strains were isolated from waste mushroom bed of Agaricus bisporus in Buyeo-Gun, Chungnam and screened for the production of indole acetic acid (IAA). The best IAA producing strain was identified as Pantoea rodasii using 16S rRNA analysis. In addition to the IAA production, this strain could act as an efficient phosphate solubilizer (1100 ${\mu}g$ $ml^{-1}$ after 5 days of incubation) also. The selected strain was cultured under different conditions in order to assess the optimum conditions for maximum IAA production. The nutrient broth (NB) medium was recorded as the best medium, where the maximum IAA production (229 ${\mu}g$ $ml^{-1}$) was recorded at the start of stationary phase (12 hours after inoculation) of the bacteria growth. The performance of the strain was found to be maximum at the temperature of $30^{\circ}C$ followed by $25^{\circ}C$. IAA production was found to be increased with increasing tryptophan concentration (from 0.1 to 0.6%), however beyond this limit, a slight reduction in IAA production was observed. The strains' ability to produce IAA was further confirmed by extraction of crude IAA and subsequent TLC analysis. A specific spot from the extracted IAA preparation was found corresponding with the standard spot of IAA with same $R_f$ value. The results of HPLC analysis conducted in identifying and quantifying the IAA production more precisely, are in agreement with the results of the assessment done with colorimetric method. As revealed by the results of the pot experiment, the isolated strain could significantly enhance the growth (as measured by shoot and root growth) of mung bean plants compared to that of non-inoculated plants. Therefore it can be concluded that the present strain, Pantoea rodasii has great potential to be used as bio-inoculants.

• Journal of Mushroom
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• v.13 no.1
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• pp.56-62
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• 2015

A lipase producing bacterium was isolated from button mushroom bed, which showing high clear zone on agar media containing Tributyrin as the substrate. The strain was identified as Burkholderia cepacia by analysis of 16S rDNA gene sequence. Crude lipase (CL) was partially purified from 70% ammonium sulfate precipitation using the culture filtrate of B. cepacia. Immobilized lipases were prepared by cross-linking method with CL from B. cepacia and Novozyme lipase (NL) onto silanized Silica-gel as support. Residual activitiy of the immobilized CL (ICL) and immobilized NL (INL) was maintained upto 61% and 72%, respectively. Biodiesel (Fatty acid methyl ester, FAME) was recovered by transesterification and methanolysis of Canola oil using NaOH, CL and ICL as the catalysts to compare the composition of fatty acids and the yield of FAME. Total FAME content was NaOH $781mg\;L^{-1}$, CL $681mg\;L^{-1}$ and ICL $596mg\;L^{-1}$, in which the highest levels of FAME was observed to 50% oleic acid (C18:1) and 22% stearic acid (C18:0). In addition, the unsaturated FAME (C18:1, C18:2) decreased, while saturated FAME (C16:0, C18:0) increased according to increasing the reaction times with both CL and ICL, supporting CL possess both transesterification and interesterification activity. When reusability of ICL and INL was estimated by using the continuous reaction of 4 cycles, the activity of ICL and INL was respectively maintained 66% and 79% until the fourth reaction.

• Journal of Mushroom
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• v.14 no.4
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• pp.162-167
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• 2016

Lactic acid bacteria (LAB) producing phenyllactic acid (PLA), which is known as antimicrobial compound, was isolated from button mushroom bed and the isolated LAB was identified to Lactobacillus casei by 16 rRNA gene sequence analysis. Cell-free supernatant (CFS) from L. casei was assessed for both the capability to produce the antimicrobial compound PLA and the antifungal activity against three fungal pathogens (Rhizoctonia solani, Botrytis cinerea, and Collectotricum aculatum). PLA concentration was investigated to be 3.23 mM in CFS when L. casei was grown in MRS broth containing 5 mM phenylpyruvic acid as precursor for 16 h. Antifungal activity demonstrated that all fungal pathogens were sensitive to 5% CFS (v/v) of L. casei with average growth inhibitions ranging from 34.58% to 65.15% (p < 0.005), in which R. solani was the most sensitive to 65.15% and followed by C. aculatum, and B. cinerea. The minimum inhibitory concentration (MIC) for commercial PLA was also investigated to show the same trend in the range of 0.35 mg mL-1 (2.11 mM) to 0.7 mg mL-1 (4.21 mM) at pH 4.0. The inhibition ability of CFS against the pathogens were not affected by the heating or protease treatment. However, pH modification in CFS to 6.5 resulted in an extreme reduction in their antifungal activity. These results may indicate that antifungal activities in CFS was caused by acidic compounds like PLA or organic acids rather than protein or peptide molecules.

• The Korean Journal of Mycology
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• v.20 no.3
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• pp.229-233
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• 1992

Although there were differences depending on strains and environmental conditions, virus infected oyster mushroom, Pleurotus florida showed slow growth on sawdust and rice straw substrates. Many harmful microorganisms occurred on the cultural bed of virus infected isolates. Pinhead formed too densely or too rarely sometimes. Stipes of the mushrooms were long slightly bent with small cap. The virus infected mushrooms formed branch on their stipes. The first pinheading days of the infeeted mushroom were later than that of healthy culture. The loss of fruit body yield was about 30% compared with that of virus free culture. Spores which contaminated by viruses damaged more seriously than the other source. The authors would like to call these symptoms as a new disease in oyster mushroom culture in the world.

• The Plant Pathology Journal
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• v.38 no.5
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• pp.472-481
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• 2022

Brown blotch disease, caused by Pseudomonas tolaasii, is one of the most serious diseases in mushroom cultivation, and its control remains an important issue. This study isolated and evaluated pathogen-specific bacteriophages for the biological control of the disease. In previous studies, 23 varieties of P. tolaasii were isolated from infected mushrooms with disease symptoms and classified into three subtypes, Ptα, Ptβ, and Ptγ, based on their 16S rRNA gene sequences analysis and pathogenic characters. In this study, 42 virulent bacteriophages were isolated against these pathogens and tested for their host range. Some phages could lyse more than two pathogens only within the corresponding subtype, and no phage exhibited a wide host range across different pathogen subtypes. To eliminate all pathogens of the Ptα, Ptβ, and Ptγ subtype, corresponding phages of one, six, and one strains were required, respectively. These phages were able to suppress the disease completely, as confirmed by the field-scale on-farm cultivation experiments. These results suggested that a cocktail of these eight phages is sufficient to control the disease induced by all 23 P. tolaasii pathogens. Additionally, the antibacterial effect of this phage cocktail persisted in the second cycle of mushroom growth on the cultivation bed.

• The Korean Journal of Soil Zoology
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• v.2 no.1
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• pp.59-64
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• 1997

A study was carried out to investigate the distribution of termites at the southern part of Korea between 1995 and 1996. During the survey, termite samples were collected from the randomly selected areas. Most of thern were collected from the decayed woods in dead trees (usually in pine trees), but some were also collected from woodern walls, floors in houses, or in matured bed logs at the mushroom cultivating areas. Damage by this termite species were also observed by Kim and Hwang (1996) who investigated the insect pests of mushroom in the southern part of Korea. To control the termites, it is urgent to identify them and to conduct ecological study of termites. Thus, we firstly identified termites which were collected from the sampling areas including houses and mushrooms cultivating fields. All termite samples were identified as Reticulitermes speratus. However, there were several morphological differences among them according to the collected areas, and the samples were reexamined, identified and divided into subspecies as R. speratus kyushuensis.

• Journal of Mushroom
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• v.6 no.3_4
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• pp.146-149
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• 2008

Pleurotus pulmonarius usually grows on the dead wood of deciduous trees in mid summer to early fall. The pileus color is white to tan and fruiting body is generally smaller than P. ostreatus. This study was carried out to investigate the characteristics of cultivation and consumer acceptance of P. pulmonarius. The period of incubation and primordial occurrence were required about 33days, 5days in bottle cultivation repectively, and the yield was 170g/850cc bottle. In bed cultivation, the period of primordial occurrence was similar to that of bottle cultivation and the yields was $35.7{\sim}46.2kg/3.3m^2$. Taste and favor of P. pulmonarius were superior to P. oostreatus., but the appearance, color and shape, was slightly inferior to P. ostreatus.

• The Korean Journal of Mycology
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• v.26 no.1 s.84
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• pp.31-38
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• 1998

Since 1990, destructive yellow rots on Ganoderma lucidum caused by a soilborne fungus have been occurred in major cultivation areas of Korea. Incidences of the disease were 61% in Chulwon and 94% in Kanghwa area where the mushroom has been cultivated for 10 years, whereas the disease has not been found yet in new cultivation areas such as Moonkyung and Hongsung. when severely infected, inner tissues of bed-logs showed severe yellow and fruiting bodies of the mushroom was not produced. Infected tissues of bed-logs were readily distinguished from those of healthy ones by a distinctive brown border line. When the disease progressed, mycelia of Ganoderma lucidum were totally destroyed, and abundant ascocarps of the pathogen were formed inside the tissues of bed-logs showing yellowish green. The fungus derived from a single ascospore strongly lysed mycelia of Ganoderma lucidum growing on bottle media, and non-volatile components secreted by the pathogen were also highly inhibitory to mycelial growth of the mushroom fungus. The pathogen was identified as Arthrographis cuboidea based on its distinctive cultural and morphological characters. The fungus produced arthroconidia and unbrached conidiophores. The width of fungal conidia was distinctively wide as compared with the length. Colonies of the fungi were pale yellow to yellowish green on agar media. As a causal pathogen of yellow rot of Ganoderma lucidum., this fungus has not been reported yet in Korea.