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An electrophoretic karyotype of Korean Flammulina velutipes was obtained using contour-clamped homogeneous electric field (CHEF) gel electrophoresis. The monokaryotic progenies (4019-20 and 4019-18) and a dikaryotic strain (4019-2018) had 6-8 chromosomes, with sizes ranging from 1.6 to 5.8 megabase (Mb) pairs. Among the 3 strains that were examined, strain 4019-20 resolved into at least 7 chromosomes, with a total genome size of approximately 26.7Mb. We selected several chromosome-specific genes from the cDNA library of F. velutipes using Southern hybridization analysis. In order to determine the whole genome sequence, we constructed a bacterial artificial chromosome (BAC) library of the 4019-20 strain. The BAC library comprised 3840 clones, and the insert size ranged from 60 to 228kb, with an average size of 136kb.

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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.

were extracted from spent mushroom compost (SMC) of Pleurotus eryngii. Different extraction buffers and conditions were tested for optimal recovery of the enzymes. The optimum extraction was shaking incubation (200 rpm) for 2 h at 4 o C. α-Amylase was extracted with the productivity range from 1.20 to 1.6 Unit/SMC g. Cellulase was recovered with the productivity range from 2.10 to 2.80 U/gf. β-glucosidase and β-xylosidase productivities showed lowest recovery producing 0.1 U/g and 0.02 U/g, respectively. The P. eryngii SMCs collected from three different mushroom farms showed different recovery on laccase and xylanse, cellulase. Furthermore, the water extracted SMC was compared to commercial enzymes for its industrial application in decolorization and cellulase activity.

: Twelve Universal fungal PCR fingerprint (UFPF) primers that were modified from Universal rice primer (URP) were used to assess genetic diversity of 64 Agaricus strains including 45 A. bisporus strains and other 19 strains of other Agaricus spp. Eight primers, UFPF1, UFPF2, UFPF3, UFPF7, UFPF9, UFPF10, UFPF11, and UFPF12 produced PCR polymorphic bands within and between the Agaricus species. Primer UFPF7 produced specific PCR polymorphic bands that are distinct Korean strain from different strains. Ninety five PCR polymorphic bands were inputted for UPGMA cluster analysis. Forty five strains of A. bisporus are genetically clustered into 8 groups, showing coefficient similarity from 0.75 to 0.9 among them. The varieties, Saea, Saedo, Saejeong and Saeyeon that have recently been developed in Korea were involved in the same group with close genetic relationship of coefficient similarity over 0.96, whereas, other Korean strains were genetically related to A. bisporus strains that were introduced from USA, Eroupe and Chinese. KEYWORDS : Agaricus bisporus

Background and Objectives: Due to the unexpected spread of coronavirus disease 2019 (COVID-19), there was a serious crisis of emergency medical system collapse. Healthcare workers working in the emergency department were faced with psychosocial stress and workload changes. Materials and Methods: This was a cross-sectional survey of healthcare workers in the emergency department in Daegu and Gyeongbuk, Korea, from November 16 to 25, 2020. In the survey, we assessed the general characteristics of the respondents; changes in the working conditions before and after the COVID-19 pandemic; and resulting post-traumatic stress disorder, depression and anxiety statuses using 49 questions. Results: A total of 529 responses were collected, and 520 responses were included for the final analyses. Changes in working conditions and other factors due to COVID-19 varied by emergency department level, region and disease group. Working hours, intensity, role changes, depression and anxiety scores were higher in the higher level emergency department. Isolation ward insufficiency and the risk of infection felt by healthcare workers tended to increase in the lower level emergency department. Treatment and transfer delay were higher in the fever and respiratory disease groups (M = 3.58, SD = 1.18; M = 4.08, SD = 0.95), respectively. In all the disease groups, both treatment and transfer were delayed more in Gyeongbuk than in Daegu. Conclusions: Different goals should be pursued by the levels and region of the emergency department to overcome the effects of the COVID-19 pandemic and promote optimal care.

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