• Journal of Mushroom
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• v.12 no.3
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• pp.220-225
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• 2014

This study was conducted to set the proper sterilization standards of casing soil for the stable production of button mushroom(Agaricus bisporus) from mushroom disease that occurs in infection of casing soil material. Changes of aerobic bacteria are increased as the longer grow-out period and sharply increased after second flushes. Fluorescence Psuedomonas showed high density at high sterilization temperature and $100^{\circ}C$ treatment has extremely high density at 30 min and 60 min in casing 22 days. Density of thermophilic actinomyces is sharply increase from casing with soil and the highest density at 22 days of casing and rapidly decrease after first flushes. Sterilizing temperature of casing soil affects quality and quantity of button mushroom. Treatment of 60 min, 90 min at $80^{\circ}C$ and 30 min at $100^{\circ}C$ produced the highest mushroom yields, especially mushrooms yields of A grads were the highest at treatment of 90 min at $80^{\circ}C$. Treatment of 60min at $100^{\circ}C$ products many yields, however, this treatment has low economic feasibility for its yields. Sterilizing temperature of casing soil has an effect on generating diseases and insect pests. Treatment of 60 min, 90 min at $80^{\circ}C$ and 30 min $100^{\circ}C$ showed lower incidence than the other treatment. Although treatment of 30 min at $100^{\circ}C$ causes low diseases and mushroom fly damage, it has low mushroom yields. Furthermore, although treatment of 60 min at $100^{\circ}C$ has high mushroom yields, it causes high diseases and mushroom fly damage. Therefore the best conditions for the sterilization of casing soils was 60 min and 90 min at $80^{\circ}C$.

• 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.

• Mycobiology
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• v.43 no.1
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• pp.81-86
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• 2015

To promote the selection of promising monokaryotic strains of button mushroom (Agaricus bisporus) during breeding, 61 progeny strains derived from basidiospores of two different lines of dikaryotic parental strains, ASI1038 and ASI1346, were analyzed by nucleotide sequencing of the intergenic spacer I (IGS I) region in their rDNA and by extracellular enzyme assays. Nineteen different sizes of IGS I, which ranged from 1,301 to 1,348 bp, were present among twenty ASI1346-derived progeny strains, while 15 different sizes of IGS I, which ranged from 700 to 1,347 bp, were present among twenty ASI1038-derived progeny strains. Phylogenetic analysis of the IGS sequences revealed that different clades were present in both the ASI10388- and ASI1346-derived progeny strains. Plating assays of seven kinds of extracellular enzymes (${\beta}$-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease) also revealed apparent variation in the ability to produce extracellular enzymes among the 40 tested progeny strains from both parental A. bisporus strains. Overall, this study demonstrates that characterization of IGS I regions and extracellular enzymes is useful for the assessment of the substrate-degrading ability and heterogenicity of A. bisporus monokaryotic strains.

• Journal of Mushroom
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• v.11 no.4
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• pp.187-193
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• 2013

A galactose fermentation bacterium producing lactose from red seaweed, which was known well to compromise the galactose as main reducing sugar, was isolated from button mushroom bed in Buyeo-Gun, Chungchugnamdo province. The lactic acid bacteria MONGB-2 was identified as Lactobacillus paracasei subsp. tolerans by analysis of 16S rRNA gene sequence. When the production of lactic acid and acetic acid by L. paracasei MONGB-2 was investigated by HPLC analysis with various carbohydrates, the strain MONGB-2 efficiently convert the glucose and galactose to lactic acid with the yield of 18.86 g/L and 18.23 g/L, respectively and the ratio of lactic acid to total organic acids was 1.0 and 0.91 g/g for both substrates. However, in the case of acetic acid fermentation, other carbohydrates besides galactose and red seaweed hydrolysate could not be totally utilized as carbon sources for acetic acid production by the strain. The lactic acid production from glucose and galactose in the fermentation time courses was gradually enhanced upto 60 h fermentation and the maximal concentration reached to be 16-18 g/L from both substrates after 48 h of fermentation. The initial concentration of glucose and galactose were completely consumed within 36 h of fermentation, of which the growth of cell also was maximum level. In addition, the bioconversion of lactic acid from the red seaweed hydrolysate by L. paracasei MONGB-2 appeared to be about 20% levels of the initial substrates concentration and this results were entirely lower than those of galactose and glucose showed about 60% of conversion. The apparent results showed that L. paracasei MONGB-2 could produce the lactic acid with glucose as well as galactose by the homofermentation through EMP pathway.

• Journal of Mushroom
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• v.18 no.4
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• pp.323-330
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• 2020

Agaricus bisporus is an important edible mushroom that is used as a functional food. In this study, European A. bisporus strains were analyzed for genetic diversity, population structure, and genetic differentiation using simple sequence repeat (SSR) markers. European A. bisporus strains were divided into four groups by distance-based analysis and two subpopulations by model-based analysis. The SSR markers used in this study did not group European A. bisporus strains by geographical region or pileus color. Genetic diversity was high in Group 4 based on distance-based analysis and Pop. 2 based on model-based analysis. A. bisporus strains showed very low genetic differentiation. The results of this study can be used for breeding A. bisporus in the future.

• Journal of Mushroom
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• v.15 no.3
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• pp.134-138
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• 2017

The white button mushroom, Agaricus bisporus, is commercially the fifth most important edible mushroom, accounting for the production of 9,732 tons of mushrooms in Korea in 2015. The genus Agaricus has been known for its potential to degrade lignocellulosic materials. Chemical analyses carried out during the cultivation of A. bisporus indicated that the cellulose, hemicellulose, and lignin fractions were changed preferentially for both vegetative growth and sexual reproduction. We screened A. bisporus strains for effective biodegradation through extracellular enzyme activity using cellulase, xylanase, and ligninolytic enzymes. The enzyme biodegradations were conducted as follows: mycelia of collected strains were incubated in 0.5% CMC-MMP (malt-mops-peptone), 0.5 Xylan-MMP, and 0.5% lignin-MMP media for 14 days. Incubated mycelia were stained with 0.2% trypan blue. Eighteen strains were divided into 8 groups based on different extracellular enzyme activity in MMP media. These strains were then incubated in sterilized compost and compost media for 20 days to identify correlations between mycelial growth in compost media and extracellular enzyme activity. In this study, the coefficient of determination was the highest between mycelial growth in compost media and ligninolytic enzyme activity. It is suggested that comparison with ligninolytic enzyme activity of the tested strains is a simple method of screening for rapid mycelial growth in compost to select good mother strains for the breeding of A. bisporus.

• Journal of Mushroom
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• v.16 no.4
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• pp.279-286
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• 2018

The button mushroom, Agaricus bisporus, is one of the most widely cultivated mushrooms. The domestic production of cultivated mushrooms in 2016 was approximately 10,173 tons, with a total value of 59 billion won. Currently, 10 cultivars have been developed; however, Korean farmers continue to demand new cultivars of mushrooms with improved quality. To breed superior lines, KMCC00754 and KMCC00775 were selected as mother strains from the 170 collected genetic resources. The putative homokaryotic strains were 25 strains from the 120 SSIs of KMCC00754 and six strains from the 120 SSIs of KMCC00775 selected by using the AbSSR45 marker. These homokaryotic strains were crossed with each other and the crossing was confirmed by SSR analysis. Seventy-four lines were crossed into 150 lines for a 50% ratio of crossing. Abs2-2015-16 was selected as a superior line by three cultivations. A new cultivar, 'Dodam', was developed in 2017.

• Journal of Mushroom
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• v.16 no.4
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• pp.239-249
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• 2018

The global mushroom industry has grown rapidly in recent years in terms of beneficial effects, market value, and demand. India has a wide range of agro-climatic conditions and is largely an agricultural country with a cultivated area of about 4.37 %, generating about 620 million tons of agro waste annually. Mushroom cultivation not only helps recycle agro wastes, but also fills the nutritional gap prevalent among a large population of India. Recently, government industrial policy and creative innovation has promoted research and other endeavors aiming towards the cultivation of mushrooms. Mushroom cultivation in India was initiated in Solan, in the mid-sixties. Mushroom cultivation has been successful in temperate regions of the Himalayas, the Western Ghats, and the hills of northeast India. Recently, many unemployed people have begun to adopt mushroom cultivation as a means of self-employment. It is high time that Indian mushroom cultivators and consumers became aware of the nutritional and medicinal values of cultivated and wild species of mushrooms. The total mushroom production in India between 2010 and 2017 was approximately 0.13 million tons, accounting for a 4.3% increase in the average growth rate of mushrooms per annum. In particular, the total production of white button mushrooms is the highest, with a share of about 73% of total mushroom production. In this review article, we have analyzed the current scenario of the Indian mushroom industry and its contribution to the economic growth of the country.

• Journal of Mushroom
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• v.17 no.1
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• pp.12-18
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• 2019

An auxin-producing bacterium Yangsong-1 was isolated from a button mushroom bed in Chung cheongnam-do. The strain Yangsong-1 was classified as a novel strain of Arthrobacter enclensis based on a chemotaxonomic and phylogenetic analysis. The isolated A. enclensis Yangsong-1 was confirmed to produce indole-3-acetic acid (IAA), which is one of the auxin hormones. When the concentration of IAA was assessed by HPLC quantity analysis, the maximum concentration of IAA, $152.903mg\;L^{-1}$, was detected from the culture broth incubated in R2A medium containing 0.2% L-tryptophan for 48 h at $35^{\circ}C$. A negative relationship between IAA production and pH was estimated to show that the increase in IAA caused pH acidification of the culture. The effect of the supplement on L-tryptophan, a known precursor of IAA production, appeared to be at maximal production at 0.2% concentration and was rather reduced at concentration above 0.4%. To investigate the growth-promoting effects on the crops, the culture broth of A. enclensis Yangsong-1 was placed in water cultures and seed pots of mung beans and lettuce. In consequence, the adventitious root induction and root growth of mung beans and lettuce were 1.5 and 1.9 times higher, respectively, than those of the control.

• Korean Journal Plant Pathology
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• v.10 no.3
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• pp.197-210
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• 1994

This experiment was carried out to study the cause of degeneration and rot of cultivated mushroom. Among 597 bacterial isolates derived from the rots of Button mushroom (Agaricus bisporus), Oyster mushroom (Pleurotus ostreatus) and Oak mushroom (Lentinus edodes) collected from markets of 5 cities (Seoul, Suwon, Taegu, Pohang and Pusan) in Korea (1991~1993), 111 bacterial isolates (18.5%) were proved as pathogenic bacteria. These pathogenic bacteria causing bacterial rots of cultivated mushrooms were identified as Pseudomonas tolasii, P. agarici, and Eriwinia sp., and the main causal bacteria were P. tolaasii. P. fluorescens and Klebsiella plenticola were confirmed as saprophytic non-pathogenic bacteria. One hundred fifty nine isolates (Group No. 39) of the 486 saprophytic bacterial isolates were classified as P. fluorescens, and this species was most often found rot area of cultivated mushrooms. P. tolaasii, the causal organism of bacterial blotch, was classified into two groups; One group can be differentiated from the other by the formation of white precipitation band by white line reacting organisms of Pseudomonas Agar F media. P. tolaasii attacked the cultivated mushrooms relatively well at lower incubation temperature such as 5$^{\circ}C$, but P. agarici rarely attack at below 1$0^{\circ}C$. The temperature for the infection commercial cultivated mushrooms by P. agarici was higher than that of P. tolaasii. Optimum temperature for the infection of mushrooms by P. tolaasii and P. agarici were 2$0^{\circ}C$ and $25^{\circ}C$, respectively.