• Mycobiology
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• v.37 no.1
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• pp.62-66
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• 2009

The internal stipe necrosis of cultivated mushrooms (Agaricus bisporus) is caused by the bacterium Ewingella americana, a species of the Enterobacteriaceae. Recently, Ewingella americana was isolated from cultivated white button mushrooms in Korea evidencing symptoms of internal stipe browning. Its symptoms are visible only at harvest, and appear as a variable browning reaction in the center of the stipes. From these lesions, we isolated one bacterial strain (designated CH4). Inoculation of the bacterial isolate into mushroom sporocarps yielded the characteristic browning symptoms that were distinguishable from those of the bacterial soft rot that is well known to mushroom growers. The results of Gram stain, flagellal staining, and biochemical tests identified these isolates as E. americana. This was verified by pathogenicity, physiological and biochemical characteristics, and the results of an analysis of the 16S rRNA gene sequences and the fatty acids profile. This is the first report of the isolation of E. americana from cultivated white button mushrooms in Korea.

• Journal of Mushroom
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• v.19 no.2
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• pp.103-108
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• 2021

This experiment investigates the characteristics of microorganisms isolated from a medium during cultivation process and reveals the relationship between these microorganisms and the growth of Agaricus bisporus. The domestically grown strains of Agaricus bisporus displayed a higher inhibition growth rate against microorganisms isolated from straw, chicken manure, and medium than imported strains. As for inhibition of mycelial growth among mushroom cultivars of the microorganisms separated by each fermentation step from the mushroom medium, the domestic cultivar, 'Saedo,' grew more vigorously among other cultivars. As the fermentation progressed, it was confirmed that inhibitation of microorganisms against Agaricus bisporus was weakened. A total of 21 strains of microorganisms that promote mushroom growth were isolated in the 4th turning process, and the microorganisms isolated from the mushroom medium affect the growth and as yield of the mushroom through secretory substances.

• Journal of Mushroom
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• v.14 no.3
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• pp.81-89
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• 2016

White button mushroom (Agaricus bisporus) is the most widely consumed mushroom in the world, and domestic consumption is increasing owing to expansion of the westernized diet in recent years. Before 2000, most Korean mushroom farmers cultivated foreign varieties, but recently, Korean breeders are developing hybrid strains using molecular breeding tools. To produce a better mushroom cultivar, we evaluated some traits of button mushroom Agaricus bisporus strains. Mycelial growth rate at different culture temperatures was investigated by 25>20>15>30>$10^{\circ}C$. Recently developed domestic varieties had superior mycelial growth rate compared to the traditionally grown species. In particular, the ASI1338 strain showed excellent mycelial growth rate at different temperatures. Further, we confirmed that ASI1007, ASI1085, ASI1310, ASI1339 were strongly resistant to bacterial brown blotch, whereas ASI1053, ASI1103, ASI1140, ASI1146, ASI1177, ASI1183, ASI1195, ASI1321, ASI1331, ASI1336 were relatively weakly resistant. The average number of days for 16.5, and that for harvest was 5.7; the average yield was 142.7 g/2-kg bag. Mycelial growth rates at 10, 15, 20, $25^{\circ}C$ were similar, but that at $30^{\circ}C$ was lower. The mushroom yield was highly correlated with the number of days for pinheading and harvest.

• Journal of Mushroom
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• v.19 no.4
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• pp.336-340
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• 2021

The cleaved amplified polymorphic sequence (CAPS) marker uses a restriction enzyme recognition site resulting from single nucleotide polymorphisms and insertions and deletions on the DNA sequence. This technique does not require expensive equipment, the process is simple, and clear results can be obtained reliably. In this study, Agaricus bisporus cultivars SaeA, SaeDo, SaeHan, SaeYeon, SaeJeong, Dodam, Seolgang, Dahyang, Hogam, and Hadam developed in Korea were discriminated using four CAPS markers. Our results indicated that it is possible to distinguish the ten cultivars and determine the genetic diversity among them.

• 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 Microbiology and Biotechnology
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• v.19 no.3
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• pp.271-276
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• 2009

Functional gene studies in the cultivated white button mushroom Agaricus bisporus have been constrained by the absence of effective gene-silencing tools. Using two endogenous genes from A. bisporus, we have tested the utility of dsRNA hairpin constructs to mediate downregulation of specific genes. Hairpin constructs for genes encoding orotidine 5'-monophosphate decarboxylase (URA3) and carboxin resistance (CBX) were introduced into A. bisporus using Agrobacteriummediated transfection. Although predicted changes in phenotype were not observed in vitro, quantitative-PCR analyses indicated unambiguously that transcripts in several transformants were substantially reduced compared with the non-transformed controls. Interestingly, some hairpin transformants exhibited increased transcription of target genes. Our observations show that hairpin transgenic sequences can mediate downregulation of A. bisporus endogenous genes and that the technology has the potential to expedite functional genomics of the mushroom.

• Journal of Mushroom
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• v.12 no.4
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• pp.293-298
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• 2014

This study was analyzed by HPLC that the changing sugar contents according to the strains of Agaricus bisporus and cultivation temperature. All strains showed that high total amino acid content in $19^{\circ}C$. 103 strain have been identified as the lowest total amino acids and amino acids content compare to the other strains. The amino acid 'cysteine' content is the highest, followed by phenylalanine, glutamic acid, lysine, proline, histidine. This big difference is estimated because in the strains of A. bisporus and cultivated temperature.

• The Korean Journal of Mycology
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• v.19 no.1
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• pp.85-87
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• 1991

Prochloraz of fungicide was applied on Mycogone perniciosa causing wet bubble in cultivated mushroom, Agaricus bisporus. In vitro, Prochloraz was an excellent fungicide on two strains of Mycogone, tolerant and non-tolerant to Benomyl, respectively. At the low dosage, Prochloraz more inhibited mycelial growth of mushrooms than Benomyl. At the higher dosage, Benomyl more inhibited the mycelial growth than prochloraz. The higher yield of sporophore of the mushroom with low inferction rate was abtained from several trial of Prochloraz. Prochloroz was concluded to be effective fungicide on Mycogone perniciosa on Agaricus cultivation.

• Korean journal of food and cookery science
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• v.33 no.2
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• pp.174-180
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• 2017

Purpose: The purpose of this study was to investigate quality characteristics and antioxidant effects on storage by temperature between new cultivar Dewdrop Pine Mushroom (Lentinula edodes GNA01) and button mushroom (Agaricus bisporus). Methods: Dewdrop Pine Mushroom and button mushroom were prepared at low storage temperature. Results: Weight loss increased with time, whereas the new cultivar Dewdrop Pine Mushroom showed a decrease of less than 4% until 15days. Hardness of new cultivar Dewdrop Pine Mushroom was reduces less than button mushroom during storage. Color change of new cultivar Dewdrop Pine Mushroom was not altered during storage. For viable cell count, new cultivar Dewdrop Pine Mushroom proliferated less than button mushroom. For antioxidant activity, polyphenol content increased with storage period of both mushrooms. The electron-donating action of new cultivar Dewdrop Pine Mushroom maintained high antioxidant activity accounting for 80% until 12 days of storage. New cultivar Dewdrop Pine Mushroom was evaluated as better than pine mushroom as it exceeded the middle of storage in sensory characteristics; such as appearance, color, aroma and overall acceptability, etc. Conclusion: In summary, new cultivar Dewdrop Pine Mushroom was stored for 12 days while button mushroom was stored for 9 days.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.362-365
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• 2008

Agaricus bisporus, also known as white button mushroom, is one of the most popular mushrooms consumed in Korea. This mushroom contains high concentrations of flavanoids and exhibits antioxidant activity. In this study, we examined the effects of Agaricus bisporus ethanol extract (ABE) on lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 cells. Nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) protein levels were assessed in cells treated with $100\;{\mu}M$ LPS in the presence or absence of ABE. 0.5 mg/mL of ABE suppressed NO production significantly. Moreover, ABE inhibited levels of iNOS protein. Taken together, these results suggest that ABE exerts anti-inflammatory activity in LPS-induced inflammation in RAW 264.7 cells.