Artificial Cultivation Characteristics and Bioactive Effects of Novel Tropicoporus linteus (Syn. Phellinus linteus) Strains HN00K9 and HN6036in Korea

Phellinus strains were collected from different areas in Korea. Of them, the fast mycelial growing strains were artificially cultivated on the oak logs to produce fruiting body. The varieties, Phellinus linteus ASI26099 (Korea Sanghwang) and P. baumii PBJS (Jangsoo Sanghwang) were grown under the same conditions as controls. Their cultivating characteristics including mycelial colonization, pinhead formation, and fruiting body formation rate were investigated on the logs. Basidiocarps of Phellinus strains HN00K9, HN6036, and ASI26099 were concentrically zonate and shallowly sulcate, and dark chestnut showing typical characteristics of Tropicoporus linteus (synonyum: P. linteus, Inonotus linteus, polyporus linteus), which is distinguishably different to PBJS. HN00K9 showed the highest yield of fruiting body among the mushroom strains. The β-glucan content in fruiting bodies of HN00K9 was 20% higher than those of other strains. Bioactive effects of polysaccharide samples from fruiting bodies of Phellinus strains, HN00K9, HN6036, ASI26099, and PBJS were assessed on cell viability and cytokine (IL-6 and TNF-α) inhibition and finally on anticancer to different human cancer cells.

Artificial Cultivation Characteristics and Bioactive Effects of Novel Tropicoporus linteus (Syn. Phellinus linteus) Strains HN00K9 and HN6036in Korea

Phellinus strains were collected from different areas in Korea. Of them, the fast mycelial growing strains were artificially cultivated on the oak logs to produce fruiting body. The varieties, Phellinus linteus ASI26099 (Korea Sanghwang) and P. baumii PBJS (Jangsoo Sanghwang) were grown under the same conditions as controls. Their cultivating characteristics including mycelial colonization, pinhead formation, and fruiting body formation rate were investigated on the logs. Basidiocarps of Phellinus strains HN00K9, HN6036, and ASI26099 were concentrically zonate and shallowly sulcate, and dark chestnut showing typical characteristics of Tropicoporus linteus (synonyum: P. linteus, Inonotus linteus, polyporus linteus), which is distinguishably different to PBJS. HN00K9 showed the highest yield of fruiting body among the mushroom strains. The β-glucan content in fruiting bodies of HN00K9 was 20% higher than those of other strains. Bioactive effects of polysaccharide samples from fruiting bodies of Phellinus strains, HN00K9, HN6036, ASI26099, and PBJS were assessed on cell viability and cytokine (IL-6 and TNF-α) inhibition and finally on anticancer to different human cancer cells.

Oxalic Acid from Lentinula edodes Culture Filtrate: Antimicrobial Activity on Phytopathogenic Bacteria and Qualitative and Quantitative Analyses

The culture filtrate of Lentinula edodes shows potent antimicrobial activity against the plant pathogenic bacteria Ralstonia solanacearum. Bioassay-guided fractionation was conducted using Diaion HP-20 column chromatography, and the insoluble active compound was not adsorbed on the resin. Further fractionation by high-performance liquid chromatography (HPLC) suggested that the active compounds were organic acids. Nine organic acids were detected in the culture filtrate of L. edodes; oxalic acid was the major component and exhibited antibacterial activity against nine different phytopathogenic bacteria. Quantitative analysis by HPLC revealed that the content of oxalic acid was higher in the water extract from spent mushroom substrate than in liquid culture. This suggests that the water extract of spent L. edodes substrate is an eco-friendly control agent for plant diseases.

Water Extract from Spent Mushroom Substrate of Hericium erinaceus Suppresses Bacterial Wilt Disease of Tomato

Culture filtrates of six different edible mushroom species were screened for antimicrobial activity against tomato wilt bacteria Ralstonia solanacearum B3. Hericium erinaceus, Lentinula edodes (Sanjo 701), Grifola frondosa, and Hypsizygus marmoreus showed antibacterial activity against the bacteria. Water, n-butanol, and ethyl acetate extracts of spent mushroom substrate (SMS) of H. erinaceus exhibited high antibacterial activity against different phytopathogenic bacteria: Pectobacterium carotovorum subsp. carotovorum, Agrobacterium tumefaciens, R. solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, X. axonopodis pv. vesicatoria, X. axonopodis pv. citiri, and X. axonopodis pv. glycine. Quantitative real-time PCR revealed that water extracts of SMS (WESMS) of H. erinaceus induced expressions of plant defense genes encoding beta-1,3-glucanase (GluA) and pathogenesis-related protein-1a (PR-1a), associated with systemic acquired resistance. Furthermore, WESMS also suppressed tomato wilt disease caused by R. solanacearum by 85% in seedlings and promoted growth (height, leaf number, and fresh weight of the root and shoot) of tomato plants. These findings suggest the WESMS of H. erinaceus has the potential to suppress bacterial wilt disease of tomato through multiple effects including antibacterial activity, plant growth promotion, and defense gene induction.

Cloning and Characterization of a Novel Laccase Gene, fvlac7, Based on the Genomic Sequence of Flammulina velutipes

Laccases (EC 1.10.3.2) are copper-containing polyphenol oxidases found in white-rot fungi. Here, we report the cloning and analysis of the nucleotide sequence of a new laccase gene, fvlac7, based on the genomic sequence of Flammulina velutipes. A primer set was designed from the putative mRNA that was aligned to the genomic DNA of F. velutipes. A cDNA fragment approximately 1.6-kb long was then amplified by reverse transcriptase-PCR using total RNA, which was subsequently cloned and sequenced. The cDNA sequence of fvlac7 was then compared to that of the genomic DNA, and 16 introns were found in the genomic DNA sequence. The fvlac7 protein, which consists of 538 amino acids, showed only 42~51% identity with 12 different mushroom species containing two laccases of F. velutipes, suggesting the fvlac7 is a novel laccase gene. The first 25 amino acids of Fvlac7 correspond to a predicted signal sequence, four copper-binding sites, and four N-glycosylation sites. Fvlac7 cDNA was heterologously overexpressed in an Escherichia coli system with an approximate expected molecular weight of 60 kDa.

Efficient Recovery of Lignocellulolytic Enzymes of Spent Mushroom Compost from Oyster Mushrooms, Pleurotus spp., and Potential Use in Dye Decolorization

This study was conducted in order to perform efficient extraction of lignocellulolytic enzymes amylase (EC 3.2.1.1), cellulase (EC 3.2.1.4), laccase (EC 1.10.3.2), and xylanase (EC 3.2.1.8) from spent mushroom compost (SMC) of Pleurotus ostreatus, P. eryngii, and P. cornucopiae. Optimal enzyme recovery was achieved when SMCs were extracted with 50 mM sodium citrate (pH 4.5) buffer at 4degrees C for 2 hr. Amylase, cellulase, and xylanase activities showed high values in extracts from P. ostreatus SMC, with 2.97 U/g, 1.67 U/g, and 91.56 U/g, respectively, whereas laccase activity and filter paper degradation ability were highest in extracts from P. eryngii SMC, with values of 9.01 U/g and 0.21 U/g, respectively. Enzymatic activities varied according to the SMCs released from different mushroom farms. The synthetic dyes remazol brilliant blue R and Congo red were decolorized completely by the SMC extract of P. eryngii within 120 min, and the decolorization ability of the extract was comparable to that of 0.3 U of commercial laccase. In addition, laccase activity of the SMC extract from P. eryngii was compared to that of commercial enzymes or its industrial application in decolorization.

Highly Efficient Electroporation-mediated Transformation into Edible Mushroom Flammulina velutipes

In this study, we developed an efficient electroporation-mediated transformation system featuring Flammulina velutipes. The flammutoxin (ftx) gene of F. velutipes was isolated by reverse transcription-PCR. pFTXHg plasmid was constructed using the partial ftx gene (410 bp) along with the hygromycin B phosphotransferase gene (hygB) downstream of the glyceraldehydes-3-phosphate dehydrogenase (gpd) promoter. The plasmid was transformed into protoplasts of monokaryotic strain 4019-20 of F. velutipes by electroporation. High transformation efficiency was obtained with an electric-pulse of 1.25 kV/cm by using 177 transformants/microg of DNA in 1 x 107 protoplasts. PCR and Southern blot hybridization indicated that a single copy of the plasmid DNA was inserted at different locations in the F. velutipes genome by non-homologous recombination. Therefore, this transformation system could be used as a useful tool for gene function analysis of F. velutipes.

DNA Profiles of Trichoderma spp. in Korea

Molecular approaches, internal transcribed spacer(ITS) sequences of ribosomal DNA, and Universal Rice Primer Polymerase Chain Reaction(URP-PCR) were used to investigate the genetic diversity, taxonomic complexity, and relationships of Trichoderma species in mushroom farms. Forty-one isolates of 13 Trichoderma spp. were used in this study and clustered into eight groups. The DNA fingerprint patterns and ITS1 region sequence alignment data showed similar results, but not in some species, such as T. virens, T. atroviride, T. harzianum, and T. aureoviride. Results of this study have proven that the morphology-based taxonomic system has some limitations in terms of classification. The data obtained in this study would be a good index for classifying indistinguishable Trichoderma strains.

DNA Fingerprinting Analysis of the Genus Phytophthora in Korea

In order to investigate biodiversity and establish identification system for Phytophthora spp. in Korea, a variety of band pattern was produced by using the URP (universal rice primer). The fingerprint patterns of Phytophthora spp. showed many common and variable fragments according to their isolates in distinct genotypes. In particular, P. drechsleri was classified into four distinct types (I to IV). P. drechsleri (KACC 40498 and KACC 40499) and P. cryptogea (KACC 40413) appeared to have almost equal bands despite their being different species. Ninety isolates of Phytophthora spp. were clustered into 13 groups based on UPGMA (unweighted pair group method with arithmetic means) analysis. These DNA fingerprinting data would be helpful for inter- and intra-species identification of Phytophthora species.

PCR Based Detection of Phellinus linteus using Specific Primers Generated from Universal Rice Primer (URP) Derived PCR Polymorphic Band

This study was carried out to develop specific primers for PCR detection of Phellinus linteus. Diverse genomes of 15 Phellinus spp. including five Phellinus linteus isolates were fingerprinted by Primer Universal rice primer (URP)1F. The URP-PCR pattern differentiated P. linteus isolates from other phellinus spp. A polymorphic band (2.8 kb), which is unique for P. linteus isolates, was isolated and sequenced. Twenty four-oligonucleotide primer pairs were designed based on information of DNA sequence. The primer set (PLSPF2/PLSPR1) amplified single band (2.2 kb) of expected size with genomic DNA from seven Phellinus linteus, but not with that of other Phellinus species tested. The primers could be used identically in both DNA samples from mycelium and fruit bodies. This specific primers could offer a useful tool for detecting and identifying P. linteus rapidly.

Genomic Differentiation Among Oyster Mushroom Cultivars Released in Korea by URP-PCR Fingerprinting

URP primers of 20 mer derived from repetitive sequence of rice were used to assess genetic variation of oyster mushroom consisting of 10 cultivars of Pleurotus ostreatus, two cultivars of P. florida and two cultivars of P. sajor-caju which were registered in Korea. URP2F and URP38F primers produced cultivar-specific PCR polymorphic bands in the Pleurotus species. UPGMA cluster analysis using the URP-PCR data showed that 14 Pleurotus cultivars are genetically clustered into large three groups. The URP-PCR data provided important information for more efficient breeding strategies of Pleurotus cultivars.

PCR-Based Sensitive Detection of Wood-Decaying Fungus Phellinus linteus by Specific Primer from rDNA ITS Regions

Based on the rDNA ITS sequences data, specific primer set for PCR detection of wood-decaying fungus Phellinus linteus was designed. The length of PCR products using designed primer set(SHF and SHR) was about 540 bp. Among 11 species, 17 isolates of Phellinus spp. including Phellinus linteus, P. pomaceus, P. spiculosus, P. baumi, P. pini, P. igniarius, P. gilvus, P. biscuspidatus, P. weirii, P. johnsonianus, P. robutus, and P. igniarius, seven isolates of Phellinus linteus showed about 540 bp-sized single band. This molecular technique could offer a useful tool for detecting and identifying Phellinus linteus.