• Journal of Mushroom
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• v.20 no.2
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• pp.35-42
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• 2022

This study aimed to examine the major domestic and foreign regulations related to the production of organic products. The production and consumption of organic products have been expanding due to the increase in consumer demand for safe food, as well as improved certification procedures and industry trends. In case of organic mushrooms, there were 405 certified farms nationwide in 2021, with a cultivation area of 3,886,628 m² and a planned production of 6,011 tons. Jeollanam-do has 221 farms, a cultivation area of 2,923,402 m², and a certification plan for 2,132 tons. Shiitake mushrooms are ranked first with 369 farms, a cultivation area of 3,805,636 m², and a certification plan for 3,576 tons, representing 91% of the farms, 98% of the cultivation area, and 60% of the certification planning.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.385-392
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• 2019

Currently, plastic bags are being used for sawdust cultivation of shiitake mushroom. However, due to serious environmental problems caused by the use of plastic bags, we studied the efficacy of bottle cultivation method to replace the sawdust bag method. Small detachable plastic bottles (400 g capacity) filled with Quercus spp. sawdust and wheat bran (4:1 w/w) media were incubated for 80 and 120 days. The weight loss (%) of the media was higher for the NIFoS 2464 strain at an approximate light intensity of 300 Lux than light intensity of 500 Lux; the light intensity was associated with the loss of sawdust medium-weight during the cultivation period. The highest yield was observed when the strain was cultivated for 80 days under dark conditions, 40 days under 500 Lux light, and air circulation fan speed of 30 rpm. When incubated for 120 days, mushroom yield in the bottle media was higher at 40 days of light exposure than 20 days of light exposure. In the bottle media incubated for 80 days under dark conditions, the mushrooms fruited due to repetitive water spraying on the top of the media and light stimulation during the fruiting period. The media could be separated from the bottles because the media shrank after the first harvest. These separated plastic bottles could be re-used for mushroom cultivation, thereby reducing the amount of plastic waste.

• Journal of Mushroom
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• v.11 no.1
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• pp.9-14
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• 2013

New shiitake (Lentinula edodes) strain "soohyangko" was bred for bed-log cultivation. Fruit-body production of "soohyangko" was most at summer and autumn. The fruit-body is hemispherical shape, brown colored and diameter of pileus is ca. 56 mm. Optimum temperature of fruit-body formation was $18{\sim}28^{\circ}$, and the fruiting is concentrated. The total amount of fruit-body production during 4 years (one generation) was $140kg/m^3$ log.

• The Plant Pathology Journal
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• v.29 no.4
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• pp.460-464
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• 2013

dsRNA was found in malformed cultures of Lentinula edodes strain FMRI0339, one of the three most popular sawdust cultivated commercial strains of shiitake, and was also found in healthy-looking fruiting bodies and actively growing mycelia. Cloning of the partial genome of the dsRNA revealed the presence of the RdRp sequence of a novel L. edodes mycovirus (LeV), and sequence comparison of the cloned amplicon showed identical sequences sequence to known RNA-dependent RNA polymerase genes of LeV found in strain HKA. The meiotic stability of dsRNA was examined by measuring the ratio of the presence of dsRNA among sexual monokaryotic progeny. More than 40% of the monokaryotic progeny still contained the dsRNA, indicating the persistence of dsRNA during sexual reproduction. Comparing the mycelia growth of monokaryotic progeny suggested that there appeared to be a tendency toward a lower frequency of virus incidence in actively growing progeny.

• Mycobiology
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• v.49 no.6
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• pp.599-603
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• 2021

CRISPR/Cas9 genome editing systems have been established in a broad range of eukaryotic species. Herein, we report the first method for genetic engineering in pyogo (shiitake) mushrooms (Lentinula edodes) using CRISPR/Cas9. For in vivo expression of guide RNAs (gRNAs) targeting the mating-type gene HD1 (LeA1), we identified an endogenous LeU6 promoter in the L. edodes genome. We constructed a plasmid containing the LeU6 and glyceraldehyde-3-phosphate dehydrogenase (LeGPD) promoters to express the Cas9 protein. Among the eight gRNAs we tested, three successfully disrupted the LeA1 locus. Although the CRISPR-Cas9-induced alleles did not affect mating with compatible monokaryotic strains, disruption of the transcription levels of the downstream genes of LeHD1 and LeHD2 was detected. Based on this result, we present the first report of a simple and powerful genetic manipulation tool using the CRISPR/Cas9 toolbox for the scientifically and industrially important edible mushroom, L. edodes.

• The Korean Journal of Mycology
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• v.50 no.3
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• pp.225-233
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• 2022

Pyogo (Shiitake, Lentinula edodes) is one of the most important edible mushrooms because of its outstanding nutritive and medicinal value. In the registration and protection procedure for newly developed mushroom cultivars, the application of molecular markers that can supplement the morphological characteristic-based distinction has been strongly requested. Sanjo 701 and Chamaram, newly developed at the Federation Forest Mushroom Research Center of Korea, have been characterized as innovative cultivars suitable for customer demands because of their high yields and cultivation rates. However, no technical tools can protect the rights to these important cultivars. In this study, using comparative genomic information from 23 commercially available pyogo cultivars, we identified single nucleotide polymorphisms (SNPs) that accurately differentiated Sanjo701 and Chamaram from the other cultivars. We also developed high-resolution melting analysis (HRM)-based SNP markers that discriminate among the tested 23 pyogo cultivars. The developed SNP markers can be utilized for rapid, accurate identification of pyogo cultivars with low genetic diversity and to prevent cultivar contamination caused by illegally distributed inocula. In addition, these markers can serve as a crucial scientific basis for securing the right to conserve new cultivars in international markets.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.350-358
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• 2015

Freezing is one of the main processes to extend the shelf life of foods. Before freezing, a thermal treatment is normally required to control the food quality. In this study, shiitake mushrooms were heated with boiling water and with superheated steam. After the thermal treatments, the samples were continuously frozen by an individual quick freezing (IQF) process, and put them into air-containing or vacuum packaging. Samples were stored at -12, -18 and $-24^{\circ}C$ for 24 weeks, and their physicochemical properties were determined. The lightness of the samples treated with boiling water and superheated steam was decreased by 12 and 15%, respectively, than that of the control. The hardness of all the samples rapidly increased after heat treatment. The contents of organic acids in the superheated steam treated samples were higher than those in the boiling water treated samples. Therefore, superheated steam treatment of samples may be a candidate thermal treatment to preserve frozen shiitake mushrooms.

• Journal of Mushroom
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• v.10 no.3
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• pp.120-128
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• 2012

Recently sawdust cultivation of Shiitake mushroom (Lentinula edodes) is increasing. It is important to make mycelia to be brown on the substrate surface. This browned surface in sawdust cultivation plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. In order to isolate genes which related to brown color formation, differential display method was used. Two cDNA fragments obtained by DD-PCR were 1.2 and 1.6kb and these were expressed in white colored mycelia from L. edodes, but not brown colored mycelia. Partial sequencing of these cDNA fragments showed that the 1.6kb cDNA had 100% identity with the microsatellites gene from Dugenia polichroa. However, the other 1.2kb cDNA fragment had poly T tail on 3' region of partial open reading frame on 5' region. The new primer designed based on the sequence of 1.2kb cDNA was constructed. RT-PCR analysis using the newly designed 0.12kb cDNA specific primer showed that the gene was only expressed in white color mycelia, but not in brown color mycelia. Sequence analysis of 5' region of this 1.2kb cDNA revealed that this gene contained partial open reading frame consisted of 110 amino acid. Homology search using DNASIS database showed that this gene had high sequence homology of 66.7% in DNA level and 69.2 % in amino acid level with dTDP-glucose 4,6-dehydratases gene from Arabidopsis thaliata. The dTDP-glucose 4,6-dehydratases gene was known to be function to have tolerance with oxidation stress. These results strongly suggest that this gene isolated from white mycelia of L. edodes might have a function of repressor against mycelia browning. Therefore I designated this gene as BCR (Brown Color Repressor) gene.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.828-831
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• 2005

The content of vitamin $D_2$, including its precursor ergosterol, was determined in some cultivated mushrooms to manufacture fortified Doenjang (Korean traditional soybean paste) with vitamin D by supplementation with mushroom. Ergosterol was the most abundant sterol in the mushrooms (50 to 140 mg/100 g dry weight) but the ergocalciferol portion made up only 0.065% (Pleurotus eryngii) to 2.5% (stipe part of Lentinus edodes, shiitake) of the total vitamin $D_2$ of each mushroom. Changes in these compounds in L. edodes caused by UV or solar irradiation were also evaluated. Ergocalciferol content in the pileus part of L. edodes went up to $424\;{\mu}g/100\;g$ dry weight and ergosterol levels reached 139.3 mg per 100 g dry weight at maximum levels. Ergocalciferol content increased about 50% when exposed to solar radiation and increased 377% with UV irradiation. These compounds level in Doenjang was enriched as much as supplied UV irradiated L. edodes powder to before fermentation, and the supplemented mushroom did not influence the palatability of Doenjang.

• BMB Reports
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• v.35 no.5
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• pp.465-471
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• 2002

From fruiting bodies of L. edodes strain L-54, single-spore isolates (SSIs) were collected. Two parental types of L-54 were regenerated via monokaryotization. By means of random-amplified polymorphic DNA (RAPD), DNA samples from L-54, its two parental types, and 32 SSIs were amplified with arbitrary primers. Dedikaryotization was demonstrated, and 91 RAPD-based molecular markers were generated. RAPD markers that were segregated at a 1:1 ratio were used to construct a linkage map of L. edodes. This RAPD-linkage map greatly enhanced the mapping of other inheritable and stable markers [such as those that are linked to a phenotype (the mating type), a known gene (priA) and a sequenced DNA fragment (MAT)] with the aid of mating tests, bulked-segregant analysis, and PCR-single-strand conformational polymorphism. These markers comprised a genetic map of L. edodes with 14 linkage groups and a total length of 622.4 cM.