• Mycobiology
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• v.42 no.2
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• pp.193-197
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• 2014

Laccase activity of Pleurotus ostreatus is significantly increased by the addition of apple pomace. Among various conditions, the best concentration of apple pomace and cultivation time for the production of laccase by P. ostreatus was 2.5% and 9 days, respectively. Reverse transcription polymerase chain reaction analyses of laccase isoenzyme genes, including pox1, pox3, pox4, poxc, poxa3, and poxa1b, revealed a clear effect of apple pomace on transcription induction. Our findings reveal that the use of apple pomace can be a model for the valuable addition of similar wastes and for the development of a solid-state fermenter and commercial production of oyster mushroom P. ostreatus.

• Mycobiology
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• v.46 no.1
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• pp.24-32
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• 2018

Improper disposal of herb residues in China has caused severe problems to the surrounding environment and human safety. Three herb residues, i.e., compound Kushen injection residues (CKI) and part one and part two of Qizhitongluo Capsule residues (QC1 and QC2, respectively), were used for the cultivation of Pleurotus ostreatus. The effect of the supplementation of corncobs (CC) with different herb residues on yield, nutritional composition, and antioxidant activity of P. ostreatus was investigated. Compared to the control, the higher mycelial growth rate was observed on substrates CC +30% CKI and CC +30% QC1, while the higher yield was obtained from substrates CC +30% QC2 and CC +30% CKI. Moreover, chemical analysis of fruit bodies revealed that the addition of herb residues to CC significantly increased proteins, amino acids, ashes, minerals (Na and Ca), and total phenolic contents but significantly reduced carbohydrates and $IC_{50}$ values of DPPH radicals. In addition, no heavy metals (Pb, Cd, and As) were detected in the fruiting bodies harvested from different substrate combinations. These results demonstrated that mixtures of CC with herb residues might be utilized as a novel, practical, and easily available substrate for the cultivation of P. ostreatus, which is beneficial for the effective management of herb residues.

• Journal of Microbiology and Biotechnology
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• v.22 no.2
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• pp.239-243
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• 2012

Degradation of butylbenzyl phthalate (BBP) by the white rot fungus Pleurotus ostreatus and the activities of some degrading enzymes were examined in two different media containing 100 mg/l of the compound. P. ostreatus pre-grown for 7 days in complex YMG medium was able to completely degrade BBP within an additional 24 h but degraded only 35 mg/l of BBP in 5 days of incubation in minimal medium. Fungal cell mass in the culture in YMG medium was higher in the presence than in the absence of BBP. The esterase activity of the fungal culture in YMG medium was higher than that in minimal medium and increased with the addition of BBP. On the contrary, laccase activity was higher in minimal medium and it did not increase upon the addition of BBP. General peroxidase activity increased for a few days after the addition of BBP to both media. The degradation of BBP and its metabolites by P. ostreatus thus may be attributed mostly to esterase rather than lignin-degrading laccase. In addition, the activities of the enzymes involved in BBP degradation and their changes varied significantly in the different media and culture conditions.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.767-772
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• 2008

Biodegradation of endocrine-disrupting phthalates [diethyl phthalate (DEP), dimethyl phthalate (DMP), butylbenzyl phthalate (BBP)] was investigated with 10 white rot fungi isolated in Korea. When the fungal mycelia were added together with 100 mg/l of phthalate into yeast extract-malt extract-glucose (YMG) medium, Pleurotus ostreatus, Irpex lacteus, Polyporus brumalis, Merulius tremellosus, Trametes versicolor, and T. versicolor MrP1 and MrP13 (transformant of the Mn-repressed peroxidase gene of T. versicolor) could remove almost all of the 3 kinds of phthalates within 12 days of incubation. When the phthalates were added to 5-day pregrown fungal cultures, most fungi except I. lacteus showed the increased removal of the phthalates compared with those of the non-pregrown cultures. In both culture conditions, p. ostreatus showed the highest degradation rates for the 3 phthalates tested. BBP was degraded with the highest rates among the 3 phthalates by all fungal strains. Only 14.9% of 100 mg/I BBP was degraded by the supernatant of P. ostreatus culture in YMG medium in 4 days of incubation, but the washed or homogenized mycelium of P. ostreatus could remove 100% of BBP within 2 days even in distilled water, indicating that the initial BBP biodegradation by P. ostreatus may be attributed to mycelium-associated enzymes rather than extracellular enzymes. The biodegradation rate of BBP by the immobilized cells of P. ostreatus was almost same as that in the suspended culture. The estrogenic activity of 100 mg/I DMP decreased during biodegradation by P. ostreatus.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1306-1315
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• 2017

DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane) is one of the organic synthetic pesticides that has many negative effects for human health and the environment. The purpose of this study was to investigate the synergistic effect of mixed cutures of white-rot fungus, Pleurotus ostreatus, and biosurfactant-producing bacteria, Pseudomonas aeruginosa and Bacillus subtilis, on DDT biodegradation. Bacteria were added into the P. ostreatus culture (mycelial wet weight on average by 8.53 g) in concentrations of 1, 3, 5, and 10 ml ($1ml{\approx}1.25{\times}10^9$ bacteria cells/ml culture). DDT was degraded to approximately 19% by P. ostreatus during the 7-day incubation period. The principal result of this study was that the addition of 3 ml of P. aeruginosa into P. ostreatus culture gave the highest DDT degradation rate (approximately 86%) during the 7-day incubation period. This mixed culture combination of the fungus and bacteria also gave the best ratio of optimization of 1.91. DDD (1,1-dichloro-2,2-bis(4-chlorophenyl) ethane), DDE (1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene), and DDMU (1-chloro-2,2-bis(4-chlorophenyl) ethylene) were detected as metabolic products from the DDT degradation by P. ostreatus and P. aeruginosa. The results of this study indicate that P. aeruginosa has a synergistic relationship with P. ostreatus and can be used to optimize the degradation of DDT by P. ostreatus.

• Mycobiology
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• v.44 no.4
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• pp.283-290
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• 2016

A double-stranded RNA (dsRNA) mycovirus was detected in malformed fruiting bodies of Pleurotus ostreatus strain ASI2792, one of bottle cultivated commercial strains of the edible oyster mushroom. The partial RNA-dependent RNA polymerase (RdRp) gene of the P. ostreatus ASI2792 mycovirus (PoV-ASI2792) was cloned, and a cDNA sequences alignment revealed that the sequence was identical to the RdRp gene of a known PoSV found in the P. ostreatus strain. To investigate the symptoms of PoV-ASI2792 infection by comparing the isogenic virus-free P. ostreatus strains with a virus-infected strain, isogenic virus-cured P. ostreatus strains were obtained by the mycelial fragmentation method for virus curing. The absence of virus was verified with gel electrophoresis after dsRNA-specific virus purification and Northern blot analysis using a partial RdRp cDNA of PoV-ASI2792. The growth rate and mycelial dry weight of virus-infected P. ostreatus strain with PoV-ASI2792 mycovirus were compared to those of three virus-free isogenic strains on 10 different media. The virus-cured strains showed distinctly higher mycelial growth rates and dry weights on all kinds of experimental culture media, with at least a 2.2-fold higher mycelial growth rate on mushroom complete media (MCM) and Hamada media, and a 2.7-fold higher mycelial dry weight on MCM and yeast-malt-glucose agar media than those of the virus-infected strain. These results suggest that the infection of PoV mycovirus has a deleterious effect on the vegetative growth of P. ostreatus.

• Journal of Mushroom
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• v.12 no.2
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• pp.96-106
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• 2014

The primary objective of the present study is the characterization of the somatic hybrids of dikaryon-monokaryon (di-mono) crosses in mushroom breeding. We employed this technique for developing superior strains from Pleurotus ostreatus strains with 48 intraspecific hybrids of 12 combinations between six P. ostreatus strains and one P. florida strain. The results on the experiments of hybridization rate, nuclear DNA patterns, and colors and morphology of fruit-bodies, are presented. In di-mono crosses, somatic hybrids among Pleurotus strains showed 100% of crossability as seen in those between P. ostreatus and P. florida strains indicating that the nuclei of a dikaryon is inferred to be migrated to a recipient. 87.5% of the somatic hybrids among Pleurotus strains were similar to the donor dikaryons, and 12.5% of the somatic hybrids presented DNA patterns of both parents. In 16.6% of di-mono crosses between P. ostreatus and P. florida, the nuclear DNA patterns of all hybrids showed the same or similar patterns compared to the donor dikaryons. 70.9% of the hybrids between P. ostreatus and P. ostreatus were similar to the donor dikaryons and 12.5% of them presented the DNA patterns of both parents. 79.2% of fruiting body morphology of the hybrids among Pleurotus strains were similar to the dikaryons and 20.8% of them were similar to both parents. Interestingly, the morphology of all dikaryons were dissimilar each other. All hybrid strains between dikaryon P. florida and monokaryon P. ostreatus showed the fruiting body of which colors were similar to those of the dikaryon, while the hybrids between dikaryon P. ostreatus and monokaryon P. florida were showed the combined colors of both parents. Therefore, the fruiting body color of P. florida tends to be generally dominant. In conclusion, the present study provides a way to find out and suggest superior hybrid strains using the nuclear DNA patterns of hybrids between Pleurotus strains as well as the characteristics of their fruiting bodies. The advantages of the di-mono crossing are needs to be fully utilized in mushroom breeding because it is an ideal way to develop the superior strains of Pleurotus.

• The Korean Journal of Mycology
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• v.13 no.1
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• pp.1-10
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• 1985

This experiment was undertaken to investigate proper conditions for protoplast isolation from strains of Agaricus bisporus, Flammulina velutipes, Lentinus edodes, Pleurotus florida, Pleurotus ostreatus, Pleurotus sajor-caju and Volvariella volvacea. Combination of ${\beta}-D-glucanase$, novozym 234 and snail enzyme with 0.6M $MgSO_4$ in 0.05M Na-maleate buffer, pH 5.8 was the most effective for isolation of protoplasts. High yields of protoplasts were obtained from $4{\sim}5$ days old mycelia of P. florida and P. ostreatus on mushroom complete agar medium. Protoplasts were also obtained in good yield from other fungi but A. bisporus and V. volvacea. In the latter two cases protoplast release was observed; however, the yield was much lower than those of the other fungi.

• Food Science and Preservation
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• v.24 no.3
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• pp.381-386
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• 2017

Ergocalciferol is known as having vitamin D activity. In this study, the effects of UV irradiation on the increase of egocalciferol content were investigated in 7 kinds of mushrooms, i.e, lily mushroom (Flammulina velutipes), oyster mushroom (Pleurotus ostreatus), young oyster mushroom (Pleurotus ostreatus), king oyster mushroom (Pleurotus eryngii), button mushroom (Agaricus bisporus), shiitake (Lentinula edodes), and wood ear mushroom (Auricularia auricula-judae). Mushrooms which were not exposed to UV light contained negligible amount of ergocalciferol in all kinds of tested mushrooms, but UV irradiation increased their content of ergocalciferol. Of UV A, B and C, UV B light was the most effective to increase ergocalciferol contents. In mushrooms, the increase in ergocalciferol content occurred only in the peel within 1 mm depth from the surface, which was directly exposed to the UV light. Therefore, when fresh whole mushrooms were irradiated with UV light, lily mushroom, the mushroom with a larger surface area compared to volume, such as lily mushroom, was more favorable in producing ergocalciferol. On the other hand when the mushrooms were freeze-dried and cut, the mushrooms with a higher ergosterol, such as king oyster mushroom, shiitake or button mushroom, were more favorable in generating ergocalciferol.

• The Korean Journal of Mycology
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• v.20 no.1
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• pp.51-57
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• 1992

Mitochondria in Pleurotus ostreatus were isolated and purified by stepped sucrose density gradient centrifugation, to compare the effects of organic compound on the activities of mitochondrial ATPase in Basidiomycotina with those in mammalian cell. The effects of N, N'-dicycio-hexylcarbodiimide (DCCD), carbonyl cyanide m-chlorophenylhydrazone (CCCP), sodium azide and aurovertin known as compounds to be related to electron transfer system in mitochondria were studied. A activity of mitochondrial ATPase was inhibited by 64%, 57% and 53% in the presence of 0.25 mM DCCD, 0.02 mM sodium azide and 1.5 $({\mu}g/mg\;of\;protein)$ aurovertin B, respectively. It was stimulated by 22% in the presence of 0.15 ${\mu}M$ CCCP.