• Journal of agriculture & life science
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• v.46 no.6
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• pp.157-163
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• 2012

Pleurotus eryngii. one of the most popular edible mushrooms, has been well known for its biological activities such as antioxidation, antitumor and immune modulation. Spent coffee ground(SCG) that is a waste product from the coffee industry has been continuously investigated for its reutilization. In this study, SCG was added to the fungal cultuvation medium and analyzed for its effect on the growth and physiological activity of P. eryngii mycelia. It was clearly demonstrated that SCG could accelarate mycelia growth. 1% SCG culture was very notable by showing 2.5-fold higher dry cell weight comapred to the control culture, which suggested SCG as an excellent activator for the growth of P. eryngii mycelia. By the addition of SCG, polyphenol content was increased by two fold but there was no change in polysaccharide content. In the analysis of DPPH scavenging activity, SCG was determined as a valuable source in order to significantly increase the antioxidative activity of the mycelium.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.25-30
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• 2010

In order to improve the functional benefits and storage properties of soybean tofu, fermented tofu was developed using Pleurotus eryngii mycelia. The immune activities of water and methanol extracts of the tofu were investigated. The optimal medium for the growth of Pleurotus eryngii mycelia was PD broth medium and the optimal fermentation period for the tofu was 7 days. The water and methanol extracts of the fermented tofu induced the proliferation of spleen cells at above $0.01 {\mu}g/mL$. The water extract increased IL-2, IFN-$\gamma$ production, while the methanol extract increased IFN-$\gamma$ synthesis. The water and methanol extracts of the fermented tofu induced the NO production in RAW264.7 macrophage cells at above $1 {\mu}g/mL$ and above $10 {\mu}g/mL$ concentration, respectively. The extracts also significantly increased the production of IL-6, TNF-$\alpha$, IL-1$\beta$ and GM-CSF in the cells. These results suggest that the tofu fermented with Pleurotus eryngii mycelia could be developed as a functional tofu.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.15-21
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• 2014

The promoting effect of Pseudomonas sp. P7014 on the mycelia growth of Pleurotus eryngii was investigated. An ethyl acetate fraction (F5) from the culture supernatant of the bacteria was confirmed to contain the growth promoting compound (GPC). The GPC was identified to be indole acetic acid (IAA) by TLC, HPLC, MS/MS, and NMR analyses. P. eryngii mycelia grew rapidly both on PDA and in PDB after the treatment of GPC. The promoting concentration of GPC was as low as 1.0 nM. Tryptophan, the aminated form of IAA, was confirmed to be the precursor of IAA. These results suggested that bacterial secreted compound was IAA and plays an important role in promoting growth of mushroom mycelia.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.359-371
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• 2019

To optimize the expression and secretion of ferritin protein associated with ion storage in the mushroom, Pleurotus eryngii, a recombinant secretion vector, harboring the ferritin gene, was constructed using a pPEVPR1b vector under the control of the CaMV 35S promoter and signal sequence of pathogen related protein (PR1b). The ferritin gene was isolated from the T-Fer vector following digestion with EcoRI and HindIII. The gene was then introduced into the pPEVPR1b secretion vector, and it was then named pPEVPR1b-Fer. The recombinant vector was transferred into P. eryngii via Agrobacterium tumefaciens-mediated transformation. The transformants were selected on MCM medium supplemented with kanamycin and its expression was confirmed by SDS-PAGE and western blotting. Expression of ferritin protein was optimized by modifying the culture conditions such as incubation time and temperature in batch and 20 L airlift type fermenter. The optimal conditions for ferritin production were achieved at 25℃ and after incubating for 8 days on MCM medium. The amount of ferritin protein was 2.4 mg/g mycelia, as measured by a quantitative protein assay. However, the signal sequence of PR1b (32 amino acids) seems to be correctly processed by peptidase and ferritin protein may be targeted in the apoplast region of mycelia, and it might not be secreted in the culture medium. The iron binding activity was confirmed by Perls' staining in a 7.5% non-denaturing gel, indicating that the multimeric ferritin (composed of 24 subunits) was formed in P. eryngii mycelia. Mycelium powder containing ferritin was tested as a feed additive in broilers. The addition of ferritin powder stimulated the growth of young broilers and improved their feed efficiency and production index.

• The Plant Pathology Journal
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• v.30 no.1
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• pp.82-89
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• 2014

In 2009-2010, unusual symptoms were observed on Pleurotus eryngii grown in mushroom farms in Gyeongnam Province, Republic of Korea. One of the main symptoms was a cobweb-like growth of fungal mycelia over the surface of the mushroom. The colonies on the surface rapidly overwhelmed the mushrooms and developed several spores within 3-4 days. The colonized surface turned pale brown or yellow. The fruit body eventually turned dark brown and became rancid. Koch's postulates were completed by spraying and spotting using isolated strains. The phylogenetic tree obtained from the internal transcribed spacer sequence analysis showed that the isolated fungal pathogen corresponded to Cladobotryum mycophilum (99.5%). In the fungicide sensitivity tests, the $ED_{50}$ values for the isolate with respect to benomyl and carbendazim were from 0.29 to 0.31 ppm. Benzimidazole fungicides were most effective against C. mycophilum, a causal agent of cobweb disease in P. eryngii.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.21-24
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• 2010

This study was carried out to select cell wall degrading enzymes for maximizing protoplast yield from Basidiomycetes. The protoplasts were released from spore suspension, mycelia cultured on cellophane membrane, and homogenized mycelia of Flammulina velutipes using commercial cell wall degrading enzymes. The highest yield of protoplasts was obtained from the homogenized mycelia treated with the enzyme combination of $Glucanex^R$ 200G and cellulase onozuka R-10. The protocol was also available for Pleurotus ostreatus, P. eryngii, and Hypsizygus marmoreus.

• Mycobiology
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• v.36 no.1
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• pp.13-18
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• 2008

Eight distinct bacteria were isolated form diseased mycelia of the edible mushroom, Pleurotus eryngii. 16S rDNA sequence analysis showed that the isolates belonged to a variety of bacterial genera including Bacillus (LBS5), Enterobacter (LBS1), Sphingomonas (LBS8 and LBS10), Staphylococcus (LBS3, LBS4 and LBS9) and Moraxella (LBS6). Among them, 4 bacterial isolates including LBS1, LBS4, LBS5, and LBS9 evidenced growth inhibitory activity on the mushroom mycelia. The inhibitory activity on the growth of the mushroom fruiting bodies was evaluated by the treatment of the bacterial culture broth or the heat-treated cell-free supernatant of the broth. The treatment of the culture broths or the cell-free supernatants of LBS4 or LBS9 completely inhibited the formation of the fruiting body, thereby suggesting that the inhibitory agent is a heat-stable compound. In the case of LBS5, only the bacterial cell-containing culture broth was capable of inhibiting the formation of the fruiting body, whereas the cell-free supernatant did not, which suggests that an inhibitory agent generated by LBS5 is a protein or a heat-labile chemical compound, potentially a fungal cell wall-degrading enzyme. The culture broth of LBS1 was not inhibitory. However, its cell-free supernatant was capable of inhibiting the formation of fruiting bodies. This indicates that LBS1 may produce an inhibitory heat-stable chemical compound which is readily degraded by its own secreted enzyme.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.1038-1044
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• 2006

The effects of the addition of soybeans cultured by mycelia of Pleurotus eryngii (SMP) on the characteristics of tofu were studied. Protein and ash contents of SMP were higher than those of untreated soybeans: 43.23 and 6.34% for treated soybeans, respectively, and 40.42 and 5.90% for untreated soybeans. But lipid and carbohydrate contents of SMP were lower. For minor elements, Mg and Ca contents of SMP were higher and P was lower than control. Tofu could be manufactured when SMP was added below 25% to the untreated soybean. In scanning electron microscopic observation, tofu tended to break down as the ratio of SMP was over 25% to the untreated soybean. The addition of SMP $(5{\sim}15%)$ increased the yield of tofu to $1.5{\sim}3.5%$. In textural characteristics, hardness of tofu increased as the ratio of SMP increased up to 20%. Cohesiveness, chewiness, springiness and gumminess were high in tofu which was made with $5{\sim}15%$ SMP. Savory taste and overall acceptability of the tofu prepared with $5{\sim}15%$ SMP were higher than those of control when evaluated by sensory test.

• Journal of Mushroom
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• v.15 no.1
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• pp.21-24
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• 2017

In this study, the effect of different substrates of agricultural by-products on the mycelial growth rate and density of Trametes versicolor (Turkeytail mushroom) was analyzed. We found that pepper stem and rice bran with a mixing ratio of 9:1(v/v) produced the best mycelial growth of 101 mm in 10 days, while a mixing ratio of 8:2 resulted in mycelial growth of 83 mm in 10 days. The control group treated with a 9:1 mixing ratio of oak sawdust and rice bran (v/v) produced mycelial growth of 74 mm in 10 days. The following results are in the order of beanstalk, sesame stem, and perilla stem. After the harvest of the mushrooms, the mycelial growth rate and the density of T. versicolor in each substrate were as follows the group with waste substrate of Pleurotus eryngii and rice bran with a mixing ratio of 9:1(v/v) produced the best result of 76 mm in days, while a mixing ratio of 8:2 produced of 61 mm in 10 days. The control group with a 9:1 ratio of oak sawdust and rice bran produced mycelia of 74 mm in 10 days, while a mixing ratio of 8:2 resulted in mycelia of 59 mm in10 days.

• Mycobiology
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• v.48 no.4
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• pp.313-320
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• 2020

In Pleurotus sp., green mold, which is considered a major epidemic, is caused by several Trichoderma species. To develop a rapid molecular marker specific for Trichoderma spp. that potentially cause green mold, eleven Trichoderma species were collected from mushroom farms and the Korean Agricultural Culture Collection (KACC). A dominant fungal isolate from a green mold-infected substrate was identified as Trichoderma pleuroticola based on the sequences of its internal transcribed spacer (ITS) and translation elongation factor 1-α (tef1) genes. In artificial inoculation tests, all Trichoderma spp., including T. atroviride, T. cf. virens, T. citrinoviride, T. harzianum, T. koningii, T. longibrachiatum, T. pleurotum, and T. pleuroticola, showed pathogenicity to some extent, and the observed symptoms were soaked mycelia with a red-brown pigment and retarded mycelium regeneration. A molecular marker was developed for the rapid detection of wide range of Trichoderma spp. based on the DNA sequence alignment of the ITS1 and ITS2 regions of Trichoderma spp. The developed primer set detected only Trichoderma spp., and no cross reactivity with edible mushrooms was observed. The detection limits for the PCR assay of T. harzianum (KACC40558), T. pleurotum (KACC44537), and T. pleuroticola (CAF-TP3) were found to be 500, 50, and 5 fg, respectively, and the detection limit for the pathogen-to-host ratio was approximately 1:10,000 (wt/wt).