• The Korean Journal of Mycology
• /
• v.26 no.1 s.84
• /
• pp.60-68
• /
• 1998

The effect of P. agarici and P. tolaasii causing the bacterial disease of mushrooms on the mycelial growth and fruitbody formation of F. velutipes was evaluated in laboratory. When the pathogenic bacteria was inoculated simultaneously with F. velutipes or 5 days after inoculation of F. velutipes, they significantly deterred both mycelial growth and fruitbody formation of F. velutipes in sawdust culture and showed strong inhibition under high population density. They appeared to be tender or milky in exhibiting symptom on F. velutipes by inoculating the concentration of $10^2{\sim}10^6$ of unit/g media, and their growth seemed to be stopped under $10^8\;cfu/g$ media. On $10^2\;cfu/g$ media of P. agarici and $10^4\;cfu/g$ media of P. tolaasii, there was no effect on the fruitbody yield of F. velutipes. P. tolaasii was more suppressive in the mycelial growth of F. velutipes than P. agarici, while on fruitbodies formation of F. velutipes, P. agarici showed slightly higher inhibition than that of P. tolaasii. When the bacteria was inoculated 10 days after inoculation of F. velutipes, both mycelial growth and fruit body formation were not affected nearly.

• Mycobiology
• /
• v.38 no.4
• /
• pp.331-335
• /
• 2010

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/${\mu}g$ of DNA in $1{\times}10^7$ 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.

• Journal of Mushroom
• /
• v.19 no.4
• /
• pp.285-293
• /
• 2021

The purpose of this study was to identify and characterize the laccase genes of Flammulina velutipes var. lupinicola. Five laccase genes (g1934, g1937, g2415, g2539, g5858) were selected based on the copper binding site and signal peptide analysis results using the laccase gene selected from the F. velutipes var. lupinicola genome. The size of the laccase genes of F. velutipes var. lupinicola were 1,488 bp~1,662 bp. As a result of cDNA sequence analysis, 14 to 17 introns were identified in the laccase genes. The cleavage site predicted as the signal peptide of the laccase gene was found to be located between 20 bp and 34 bp from the N-terminus. In addition, separation and purification were performed to characterize the F. velutipes var. lupinicola laccases, and the optimal activity of the separated and purified proteins were analyzed by pH, temperature and time. Five bands with laccase activity were found from zymogram analysis. The optimal pH of the reaction was 5.5, the optimal temperature was found to be 40℃. Therefore, characterization of the laccase genes identified in this study should help in better understanding the biomass decomposition of F. velutipes var. lupinicola.

• Journal of Mushroom
• /
• v.12 no.3
• /
• pp.193-200
• /
• 2014

Flammulina velutipes fruit body, Flammulina velutipes mycelium and Cordyceps militaris mycelium were analyzed for their proximate composition, protein-bound polysaccharide, nucleic acid and amino acids. The content of ash and crude fiber in F. velutipes fruit body were higher than F. mycelium and C. militaris mycelium. C. militaris mycelium showed the highest crude fat content while F. velutipes fruit body had lowest. Nitrogen free extract content of the samples varied from 56.8% in F. velutipes fruit body to 61.9% in F. velutipes mycelium. The compositions of total protein and total free sugars of protein-bound polysaccharide were found to be significant differences for all samples. Nucleic acid related compounds were identified the 5'-GMP, 5'-XMP, 5'-IMP in all samples. The content of total nucleic acids were high in the orders of F. velutipes myclial (286.71 mg%), F. velutipes fruit body(187.36 mg%) and C. militaris mycelial(76.85 mg%). The highest content of 5'-GMP was found in F. velutipes fruit body. The most nucleic acid of F. velutipes mycelial and C. militaris mycelial were the 5'-XMP. As for the analysis of total amino acids, seventeen amino acids were identified by HPLC and the major amino acid was glutamic acid in all samples. The content of total amino acids were high in the orders of F. velutipes fruit body(19,919 mg%), F. velutipes mycelium(19,018 mg%) abd C. militaris mycelium(18,965 mg%). We determined the developing new food product such as amino acid drink and amino acid containing food using extracts of Flammulina velutipes fruit body, Flammulina velutipes mycelium and Cordyceps militaris mycelium.

• Animal Bioscience
• /
• v.34 no.10
• /
• pp.1695-1704
• /
• 2021

Objective: The aim of this work was to assess the effect of ergothioneine (ESH)-enriched mushroom extract on oxidative stability, volatile compounds, and sensory quality of emulsified sausage. Methods: The ESH content was determined by high performance liquid chromatography. The antioxidant activity of Flammulina velutipes (F. velutipes) extract was determined through radical-scavenging activity of 1,1 diphenyl-2-picryl-hydrazyl, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals. Four different groups of emulsified sausage were manufactured: control, no antioxidants; BHA, 0.01% butylated hydroxyanisole; EEME, 0.8% ESH-enriched mushroom (F. velutipes) extract; AE, 0.012% authentic ESH, after storage for 14 days (at 4℃), the quality of sausage including oxidative stability (2-thiobarbituric acid reactive substances and protein carbonyls content), volatile compounds and sensory quality were studied. Results: It was demonstrated that adding ESH-enriched F. velutipes extract to sausage could effectively prevent lipid and protein oxidation, and its efficacy was equivalent with 0.01% BHA. During meat processing, the ESH mainly contributed to the antioxidative activity of F. velutipes extract. The flavor and sensory attributes of emulsified sausage were improved through adding ESH-enriched F. velutipes extract. Conclusion: Accordingly, the extract of F. velutipes contained high-level of ESH and could be a good antioxidant candidate for processed meat production.

• The Korean Journal of Mycology
• /
• v.43 no.4
• /
• pp.231-238
• /
• 2015

Genome-wide reanalyzed data of 25 Flammulina strains were compared against the reference genome (KACC42780) to establish a genome-wide single nucleotide polymorphism (SNP). The rate of mapping differences between the strains reflected in the strain variation in its result. Genome-wide SNPs distribution divided into types of homozygous SNP and heterozygous SNP moreover all of the strains demonstrated a wide variation in all of the regions. In the further study of topological relationship between the collected strains, phylogenetic tree was separated into 3 major groups. Group I contained F. velutipes var. related strains of ASI 4062, 4148, 4195. Group 2 contained strains that are different species of ASI 4188 F. elastica, ASI 4190 F. fennae, and ASI 4194 F. rossica. The other 19 strains F. velutipes were classified as a single group. However, further experiment to discriminate its genetic relationship between the white group and brown group did not verify its validity. The inferred tree exhibited a phylogenetic relationship between Korea white fruitbody forming strains of ASI 4210, 4166, 4178 and Japan white fruitbody forming strains of ASI 4209, 4167 confirmed to be genetically closely related.

• Journal of Life Science
• /
• v.22 no.1
• /
• pp.62-73
• /
• 2012

This study was carried out to investigate the genetic relationship of Flammulina velutipes with other species. The ribosomal DNA cluster containing 4 rRNA genes from F. velutipes 4154 were sequenced. The length of the rDNA cluster sequence was estimated at 7,403 bp long and consisted of 1,806 bp of SSU rDNA, 245 bp of ITS 1 region, 159 bp of 5.8S rDNA, 308 bp of ITS 2 region, 3,402 bp of LSU rDNA, 1,400 bp of IGS 1 region, and 83 bp of 5S rDNA. The F. velutipes 4154 genes were contained in the rDNA cluster of F. velutipes in the order of SSU rDNA - ITS 1 - 5.8S rDNA - ITS 2 - LSU rDNA - IGS 1 - 5S rDNA. The phylogenetic relationships of 20 strains of Tricholomataceae and Physalacriaceae were analyzed by conducting distance analysis using the Neighbor-joining (NJ) method. The 20 strains used in this study were divided into three groups and the strains of the genus Flammulina were related very closely to strains of Physalacria bambusae.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.355-358
• /
• 2001

Selection of optima] nutrient sources and cultural methods for liquid spawn culture of Flammulina velutipes were carried out. The optimal temperature and pH for mycelial growth of F. velutipes were $20^{\circ}C$ and 6.0 to 7.5. respectively. In the 250ml ${Delta}$-flask culture. the amount of inoculum and culture period for the optimal mycelial growth of F. velutipes were 3 mycelial disks(diametcr 6mm) and 6 days, respectively. For the mass production of submerged culture. the optimal inoculum amount and aeration rate of F. velutipes were 5%(inoculum vol/medium vol.) and l.0vvm(vol of air/vol. of medium/min), respectively.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.8
• /
• pp.774-780
• /
• 2009

Flammulina velutipes is a popular edible basidiomycete mushroom found in East Asia and is commonly known as winter mushroom. Mushroom development showing dramatic morphological changes by different environmental factors is scientifically and commercially interesting. To create a genetic database and isolate genes regulated during mushroom development, cDNA libraries were constructed from three developmental stages of mycelium, primordium, and fruit body in F. velutipes. We generated a total of 5,431 expressed sequence tags (ESTs) from randomly selected clones from the three cDNA libraries. Of these, 3,332 different unique genes (unigenes) were consistent with 2,442 (73%) singlets and 890 (27%) contigs. This corresponds to a redundancy of 39%. Using a homology search in the gene ontology database, the EST unigenes were classified into the three categories of molecular function (28%), biological process (29%), and cellular component (6%). Comparative analysis found great variations in the unigene expression pattern among the three different unigene sets generated from the cDNA libraries of mycelium, primordium, and fruit body. The 19-34% of total unigenes were unique to each unigene set and only 3% were shared among all three unigene sets. The unique and common representation in F. velutipes unigenes from the three different cDNA libraries suggests great differential gene expression profiles during the different developmental stages of F. velutipes mushroom.

• Mycobiology
• /
• v.41 no.1
• /
• pp.37-41
• /
• 2013

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.