Hypocreales is one of the largest orders within the class Sordariomycetes in Ascomycota. Several species of this order are cosmopolitan and have a broad range of habitats. Here, we isolated several fungal strains from environmental samples, including freshwater sediment and plant litter. The strains were identified via molecular and phylogenetic analyses of rDNA and other DNA markers, such as TUB, RPB2, and EF1. The morphological characteristics of the fungi were investigated using microscopy, and culture characteristics were assessed from their growth on several media. We identified 17 species previously unrecorded in Korea: Dactylonectria hordeicola, Flavocillium bifurcatum, Fusarium luffae, Ilyonectria ilicicola, Ilyonectria qitaiheensis, Ilyonectria robusta, Lecanicillium aphanocladii, Nectria ulmicola, Neonectria lugdunensis, Ovicillium oosporum, Pseudonectria foliicola, Sarocladium spinificis, Scolecofusarium ciliatum, Trichoderma appalachiense, Trichoderma subviride, Trichoderma taiwanense, and Trichoderma tsugarense.

비병원성 야생효모로부터 대장에서의 독성물질 활성화에 관여하여 대장암을 유발시키는 효소 중의 하나인 β-glucuronidase를 저해하는 물질을 생산하기 위하여 대전광역시 월평공원으로부터 분리 동정한 야생효모들 중 비병원성 야생효모들을 선별하여 배양 상등액과 무세포 추출물을 각각 제조한 후 β-glucuronidase 저해활성을 측정하였다. 133균주의 비병원성 야생효모들 중C. oleophila WP5-19-1의 무세포추출물이 49.0%의 가장 높은 저해활성을 보여 우수 균주로 최종 선발하였다. β-Glucuronidase 저해물질 최적 생산 조건은C. oleophila WP5-19-1를 초기 pH를 6.0으로 조정한 dextrose 5% 함유한 potato dextrose 배지에 접종하여 30℃에서 24시간 배양하였을 때였고 이때 IC50값; 8.4 mg으로 가장 높은 저해활성을 보였다. C. oleophila WP5-19-1의 β-glucuronidase 저해물질을 한외여과와 Sephadex G-50으로 gel 여과를 실시하여 부분 정제하였고 이들은 30-60℃, pH 6.0-9.0에서 80% 이상의 잔존 저해활성을 보여 안정하였다. 또한 철, 구리, 아연과 같은 중금속 이온들은 저해활성을 활성화시켰다.

We aimed to produce a potent β-glucuronidase inhibitor from wild yeast that could inactivate toxic substances in the colon. Culture supernatants and cell-free extracts of non-pathogenic wild yeasts were prepared and their β-glucuronidase inhibitory activities were measured. Cell-free extract from Candida oleophila WP5-19-1 showed the highest β-glucuronidase inhibitory activity (49.0%). The β-glucuronidase inhibitor was maximally produced (IC50 value; 8.4 mg) when C. oleophila WP5-19-1 was cultured in potato dextrose medium containing 5% dextrose (initial pH; 6.0) at 30℃ for 24 hours. β-glucuronidase inhibitor of C. oleophila WP5-19-1 was partially purified by trypsin hydrolysis, ultrafiltration (3 kDa), and Sephadex G-50 filtration. The partially purified β-glucuronidase inhibitor was stable from 30℃ to 60℃ and at pH 6.0 9.0, and showed residual inhibitory activity of about 80%.

Gastrodia elata infected with root rot disease was collected from cultivated G. elata fields in Gimcheon, Korea, in 2018. G. elata tuber surfaces exhibited root rot disease symptoms of dark-grey lesions and white fungal mycelial growth. The fungus was isolated from symptomatic tubers and cultured. Based on morphological characteristics and molecular analysis of the internal transcribed spacer region of ribosomal DNA and translation elongation factor 1-alpha, the isolated fungus was Fusarium oxysporum. This is the first report of root rot caused by F. oxysporum on G. elata tubers in Korea.

Abnormal symptoms were observed on Anemone flaccida in Korea, indicating an infection caused by smut fungi. Morphological and molecular analyses of the strain KNUF-UB were consistent with previous reports of Urocystis eranthidis. Therefore, this is the first report of smut caused by U. eranthidis on A. flaccida in Korea.

Anamorph of a powdery mildew was collected from Convolvulus arvensis (Convolvulaceae) in 2021 in Korea. Based on the morphological examination and molecular phylogenetic analyses of the internal transcribed spacer and large subunit rDNA gene, the powdery mildew was identified as Erysiphe convolvuli. This powdery mildew species is commonly found in Europe and North America, but rarely in East Asia. The holomorph of this powdery mildew was first recorded on Calystegia hederacea in Korea. Conclusively, this is the first report of E. convolvuli on C. arvensis and the second record of this powdery mildew species in Korea.

In July and September 2020, a severe outbreak of stem rot was observed on bonnet bellflower (Codonopsis lanceolata) plants in a farm located in Chuncheon, Gangwon Province, Korea. The symptoms initially appeared on the stem at or above the soil line. Later, the infected stem completely rotted and blighted. The incidence of diseased plants in the field was 2-30%. Ten isolates of Rhizoctonia sp. were obtained from the stem lesions of diseased plants. All isolates were identified as Rhizoctonia solani AG-4 based on the morphological characteristics and anastomosis test. Three isolates of R. solani AG-4 were tested for pathogenicity on bonnet bellflower plants through artificial inoculation. All tested isolates induced stem rot symptoms on the inoculated plants. The symptoms were similar to those observed in plants from the farm. This is the first report of R. solani AG-4 causing stem rot in bonnet bellflower.

본 연구는 남해안 해운대와 인근 몽돌해수욕장 주변의 야생 효모 종 분포특성을 알아보기위해 이들 지역 주변의 물과 모래, 토양 등 70점의 시료들로부터 일반 효모와 호알칼리성 균주 등 모두 37종, 41균주의 야생 효모들을 분리하였다. 이들 야생 효모들 중Cys. insectorum HUD16-3 (JSL-KSS-002)와 M. citriensis HUD12-5 (JSL-KSS-001)등 두 균주들이 국내 보고되지 않은 미기록 효모들로 선별되었고 필자 등이 전라북도 장선천 주변 토양에서 분리하여 국내 미기록 균주로 선별한 Cys. lysinophilum JSC 52-2 (JSL-GGU-019)와 대전광역시 장태산 호수 주변에서 분리하여 선별한 C. takata NMD11-1 (JSL-GGU-017), C. panamensis ASG58M-2 (JSL-GGU-018)등 5종의 미기록 야생 효모들의 균학적 특성을 조사하였다. 이들 미기록 효모들은 모두 난형으로 출아에 의해 영양 증식을 하였고 포자와 의균사를 형성하지 않았다. 미기록 효모 모두 vitamin-free배지에서도 생육하였고M. citriensis HUD12-5균주는 50% 포도당을 함유한 YPD배지에서 생육하는 강한 내당성을 보였고 Cys. insectorum HUD16-3과 M. citriensis HUD12-5균주들은 15% NaCl을 함유한 YPD배지에서도 생육이 비교적 양호한 호염성균이었다 또한, 미기록 효모들 모두 포도당과 fructose, sucrose, 전분 등을 자화시켰고 특히Cys. lysinophilum JSC 52-2등 3균주들은 lactose를 자화시켰다.

This study aimed to isolate wild yeasts from seawaters and soils samples of the Haeundae and Mongdol beaches on the southern coast of Korea, and to characterize these unrecorded wild yeast strains. In total, 41 strains, representing 37 different species of wild yeast were isolated from 70 samples collected from the beaches. Among these, 14 strains were isolated from the alkalophilic medium of yeast extract-peptone-dextrose (YPD) medium (pH 9.0), and 27 strains were isolated concurrently on general YPD medium (pH 6.5). Among the 41 isolated wild yeast strains, Candida insectorum HUD 16-3(JSL-KSS-002) and Metschnikowia citriensis HUD 12-5(JSL-KSS-001) had not previously been recorded. We investigated the microbiological characteristics of these two unrecorded yeast strains and three other strains-, Cystobasidium lysinophilum JSC 52-2(JSL-GGU-019), Candida takata NMD 11-1(JSL-GGU-017) and Candida panamensis ASG 58M-2(JSL-GGU-018) from Jangseoncheon in Jellabuk-do and Jangtaesan in Deajeon city. All five previously unrecorded yeasts were oval and did not form spores. All strains grew well in YPD and yeast extract-malt extract media in a vitamin-free medium. Two strains, including C. insectorum HUD 16-3(JSL-KSS-002) grew well in a 15% NaCl-containing YPD medium. Three strains, including Cys. lysinophilum JSC52-2(JSL-GGU-019) assimilated lactose, and all strains assimilated starch.