• Mycobiology
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• 제47권1호
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• pp.1-11
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• 2019

The distribution and occurrence of rare ascomycete fungi within freshwater samples in Korea was investigated. Three rare fungal strains, CNUFC-YR537-1, CNUFC-CNUP1-1, and CNUFC-NDR3-1, were isolated using serial dilution method. On the basis of their morphological characteristics and phylogenetic analysis of their internal transcribed spacer regions and 28S rDNA sequences, the three isolates were identified as Acrostalagmus luteoalbus, Bartalinia robillardoides, and Collariella carteri, respectively. To our knowledge, these are the first records of rare genera Acrostalagmus, Bartalinia, and Collariella from Korea, and the first reports of A. luteoalbus, B. robillardoides, and C. carteri from freshwater samples.

• 한국환경보건학회지
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• 제37권6호
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• pp.406-417
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• 2011

Objectives: Exposure to bioaerosols in the indoor environment could be associated with a variety adverse health effects, including allergic disease such atopy. The objectives of this study were to assess children's exposure to bioaerosol in home indoor environments and to evaluate the association between atopy and bioaerosol, environmental, and social factors in Ulsan, Korea. Methods: Samples of viable airborne bacteria and fungi were collected by impaction onto agar plates using a Quick Take TM 30 and were counted as colony forming units per cubic meter of air (CFU/$m^3$). Bioaerosols were identified using standard microbial techniques by differential stains and/or microscopy. The environmental factors and possible causes of atopy based on ISAAC (International Study of Allergy and Asthma in Childhood) were collected by questionnaire. Results: The bioaerosol concentrations in indoor environments showed log-normal distribution (p < 0.01). Geometric mean (GM) and geometric standard deviation (GSD) of airborne bacteria and fungi in homes were 189.0 (2.5), 346.1(2.0) CFU/$m^3$, respectively. Indoor fungal levels were significantly higher than those of bacteria (p < 0.001). The concentration of airborne bacteria exceeded the limit recommended by the Korean Ministry of Environment, 800 CFU/$m^3$, in three out of 92 samples (3.3%) from 52 homes. The means of indoor to outdoor ratio (I/O) for airborne bacteria and fungi were 8.15 and 1.13, respectively. The source of airborne bacteria was not outdoors but indoors. GM of airborne bacteria and fungi were 217.6, 291.8 CFU/$m^3$ in the case's home and 162.0, 415.2 CFU/$m^3$ in the control's home respectively. The difference in fungal distributions between case and control were significant (p = 0.004) and the odds ratio was 0.996 (p = 0.027). Atopy was significantly associated with type of house (odds ratio = 1.723, p = 0.047) and income (odds ratio = 1.891, p = 0.041). Some of the potential allergic fungal genera isolated in homes were Cladosporium spp., Botrytis spp., Aspergillus spp., Penicillium spp., and Alternatia spp. Conclusions: These results suggest that there this should be either 'was little' meaning 'basically no significant association was found' or 'was a small negative' mean that an association was found but it was minor. It's a very improtant distinction. Association between airborne fungal concentrations and atopy and certain socioeconomic factors may affect the prevalence of childhood atopy.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2016년도 춘계학술대회 및 임시총회
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• pp.13-13
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• 2016

Insects constitute the largest and most diverse group of animals in the world. They also serve as the hosts or nutrient sources for an immense assemblage of pathogens, parasites, and predators. More than 700 fungal species from 100 genera have adopted an entomopathogenic lifestyle. Although entomopathogenic fungi were studied as only biocontrol agents against a variety of pests in various countries, it has been recently focused their additional roles in nature. They are antagonists to/against plant pathogens, endophytes, and possibly even plant growth promoting agents. The potential antimicrobial effect against fungal plant pathogens by an isolate of entomopathogenic fungi including Beauveria bassiana, Lecanicillium spp., and Isaria fumosorosea have been reported since late 1990s, but wasn't reported pathogenicity of the isolate against pests. Later, a Canadian Lecanicillium sp. isolate and L. longisporium isolated from Vertalec$^{(R)}$ showed simultaneous control effect against both aphid and cucumber powder mildew. Therefore, the antimicrobial activities of 342 fungi isolates collected from various regions and conditions in Korea were evaluated against plant pathogenic fungus Botrytis cinerea using dual culture technique on agar plate. As a result, 186 isolates (54.4%) shown the antifungal activity against B. cinerea. The culture filtrates of selected fungi completely suppressed the growth of the microorganisms, indicating that suppression was due to the presence of antimicrobial substances in the culture filtrate. Mode of action of these fungi against insect involves the attachment of conidia to the insect cuticle, followed by germination, cuticle penetration, and internal dissemination throughout the insect. During infection process, secreted enzymes, proteinous toxins, and/or secondary metabolites secreted by entomopathogenic fungi can be used to overcome the host immune system, modify host behavior, and defend host resources. Recently, secondary metabolites isolated from entomopathogenic fungi have been reported as potential bioactive substances. Generally, most of bioactive substances produced by entomopathogenic fungi have reported low molecular weight (lower than 1,000 g/mol) as peptide and, in contrast the high molecular weight fungal bioactive substances are rare. Most substances based on entomopathogenic fungi were shown antimicrobial activity with narrow control ranges. In our study we analyzed the antimicrobial substances having antagonistic effects to B. cinerea. Antimicrobial substances in our fungal culture filtrates showed high thermostability, high stability to proteolytic enzymes, and hydrophilicity and their molecular weights were differed from substance. In conclusion, entomopathogenic fungi showed pathogenicity against insect pests and culture filtrate of the fungi also shown to antimicrobial activity. In the future, we can use the entomopathogenic fungi and its secondary metabolites to control both insect pest control and plant pathogenic fungi simultaneously.

• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1149-1161
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• 2014

Cotton plants were sampled and ranked according to their resistance to Verticillium wilt. In total, 642 endophytic fungi isolates representing 27 genera were recovered from Gossypium hirsutum root, stem, and leaf tissues, but were not uniformly distributed. More endophytic fungi appeared in the leaf (391) compared with the root (140) and stem (111) sections. However, no significant difference in the abundance of isolated endophytes was found among resistant cotton varieties. Alternaria exhibited the highest colonization frequency (7.9%), followed by Acremonium (6.6%) and Penicillium (4.8%). Unlike tolerant varieties, resistant and susceptible ones had similar endophytic fungal population compositions. In three Verticillium-wilt-resistant cotton varieties, fungal endophytes from the genus Alternaria were most frequently isolated, followed by Gibberella and Penicillium. The maximum concentration of dominant endophytic fungi was observed in leaf tissues (0.1797). The evenness of stem tissue endophytic communities (0.702) was comparatively more uniform than the other two tissues. Eighty endophytic fungi selected from 27 genera were evaluated for their inhibition activity against highly virulent Verticillium dahliae isolate Vd080 in vitro. Thirty-nine isolates exhibited fungistasis against the pathogen at varying degrees. Seven species, having high growth inhibition rates (${\geq}75%$), exhibited strong antifungal activity against V. dahliae. The antifungal activity of both volatile and nonvolatile metabolites was also investigated. The nonvolatile substances produced by CEF-818 (Penicillium simplicissimum), CEF-325 (Fusarium solani), CEF-714 (Leptosphaeria sp.), and CEF-642 (Talaromyces flavus) completely inhibited V. dahliae growth. These findings deepen our understanding of cotton-endophyte interactions and provide a platform for screening G. hirsutum endophytes with biocontrol potential.

• 한국균학회지
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• 제15권3호
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• pp.187-195
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• 1987

두가지 열처리법에 의한 균 분리방법을 사용하여, 보통균을 제외한 토양균의 분리와 그의 논토양중의 수직 및 계절별 분포를 파악하기 위하여 역곡동과 신원동의 논토양을 시료로 사용하였다. $42^{\circ}C$에서 2일간 배양후 $37^{\circ}C$로 배양하는 방법과 $70^{\circ}C$에서 15분간 열처리하는 방법을 사용하였다. $42^{\circ}C$ 배양법에서는 두 장소에서 분리된 토양균은 거의가 mesophile이었으며 thermotolerant fungi는 Asergillus fumigatus, thermophile로는 Sporotrichum thermophile과 Malbranchea pulchella var. sulfrea이었고, 이들 중 우점종은 Asergillus fumigatus이었다. 두 장소에서 9속, 14종이 분리동정되었으며 Sporotrichum thermophile, Talaromyces ucrainicus, Malbranchea pulchella var. sulfrea는 한국 미기록 종이다. $72^{\circ}C$ 열처리방법으로 분리한 경우 두 장소에서 10속, 20종이 분리동정되었으며, 분리된 균은 거의가 mesophile이었으며 thermotolerant fungi는 Asergillus fumigatus이었고, 우점종은 Talaromyces stipitatus이었다. 또한 Talaromyces helicus var. major, Emericella nidulans var. nidulans, Chaetomium subspirale, Neosartorya fishiri var. fischeri는 한국 미기록 종이다. 두가지 분리방법으로 분리된 토양균의 계절적 분포는 여름과 봄이 가을과 겨울보다 높았으며, 전체 균의 수와 우점종 균수, 그리고 나타나는 종의 빈도는 그 수직분포에 있어서 상층에서 가장 높았으나 하층으로 내려갈수록 감소하였다.

• 한국균학회지
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• 제46권2호
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• pp.122-133
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• 2018

순천 선암사는 산림과 계곡으로 둘러싸여 가파른 지형에 위치하고 있으며 평지보다 온 습도는 높고 바람의 세기가 약하여 생물 피해가 우려되는 곳이다. 이에 계절마다 진균상 조사를 통해 실내 외 공기질에 분포하는 진균의 농도와 다양성을 조사하였다. 외부 공기질에 분포하는 진균의 농도는 봄($276CFU/m^3$)에 가장 높았고, 가을($196CFU/m^3$), 여름($128CFU/m^3$), 겨울($24CFU/m^3$) 순으로 감소하였다. 가장 하단에 위치한 지장전은 여름철에 $337.4CFU/m^3$, 가장 상단에 위치한 원통전은 가을철에는 $333.4CFU/m^3$의 가장 높은 농도를 나타냈다. 실내 외 공기질에서 부유균 농도의 차이가 컸던 계절은 여름철이었으며 $128CFU/m^3$인 외부보다 실내 공기질에 최소 0.5배에서 최대 3배 정도의 많은 진균이 부유하고 있었다. 부유 진균이 가장 많이 수집된 계절은 봄철이었지만 다양성은 여름과 가을철 공기질에서 더 높았는데 여름에는 28속 45종, 가을에는 25속 47종의 진균이 확인되었다. 특히, 가을철에는 모든 조사 지점에서 부유 진균의 분포도가 가장 높았는데 그 중에서 자낭균이 86%를 차지하였고 Cladosporium속이 우점하였다. Penicillim속은16종이 검출되어 종다양성이 가장 높았고 야외보다는 여름과 가을, 겨울철의 실내 공기질에 주로 분포하였다.

• Mycobiology
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• 제46권2호
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• pp.85-91
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• 2018

Endophytic fungi strains (n = 81) were isolated from the leaves, barks, and fruits of Camellia oleifera from Hunan province (China) to delineate their species composition and potential as biological control agents of C. oleifera anthracnose. The fungi were identified by morphological and phylogenetic analyses. Fungal colonization rates of the leaves, barks, and fruits were 58.02, 27.16, and 14.81%, respectively. The isolates were identified as 14 genera, belonging to two subdivisions, Deuteromycotina and Ascomycotina; 87.65% of all isolates belonged to Deuteromycotina. The dominant species, occurring with a high relative frequency, were Pestalotiopsis sp. (14.81%), Penicillium sp. (14.81%), and Fusarium sp. (12.35%). The Simpson's and Shannon's diversity indices revealed the highest species diversity in the leaves, followed by the barks and fruits. The similarity index for the leaves versus barks comparison was the highest, indicating that the number of endophytic fungal species shared by the leaves and barks was higher than barks and fruits or leaves and fruits. Based on the results of dual culture experiments, only five strains exhibited antifungal activity against C. oleifera anthracnose pathogen, with isolate ty-64 (Oidium sp.) generating the broadest inhibition zones. Our results indicate that the endophytes associated with C. oleifera could be employed as natural agents controlling C. oleifera anthracnose.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.978-987
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• 2015

Aluminum (Al) toxicity is one of the greatest limitations to agriculture in acid soils, particularly in tropical regions. Arbuscular mycorrhizal fungi (AMF) can supply plants with nutrients and give protection against Al toxicity. The aim of this work was to evaluate the effects of soil liming (i.e., reducing Al saturation) on the AMF community composition and structure in the roots of maize lines contrasting for Al tolerance. To this end, we constructed four 18S rDNA cloning libraries from L3 (Al tolerant) and L22 (Al sensitive) maize lines grown in limed and non-limed soils. A total of 790 clones were sequenced, 69% belonging to the Glomeromycota phylum. The remaining sequences were from Ascomycota, which were more prominent in the limed soil, mainly in the L3 line. The most abundant AM fungal clones were related to the family Glomeraceae represented by the genera uncultured Glomus followed by Rhizophagus and Funneliformis. However, the most abundant operational taxonomic units with 27% of the Glomeromycota clones was affiliated to genus Racocetra. This genus was present in all the four libraries, but it was predominant in the non-limed soils, suggesting that Racocetra is tolerant to Al toxicity. Similarly, Acaulospora and Rhizophagus were also present mostly in both lines in non-limed soils. The community richness of AMF in the non-limed soils was higher than the limed soil for both lines. The results suggest that the soil Al saturation was the parameter that mostly influences the AMF species composition in the soils in this study.

• 한국미생물·생명공학회지
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• 제7권1호
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• pp.15-21
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• 1979

미곡저장중 곰팡이 침해 여부를 chitin 정량법으로 판정하기 위하여 상이한 수부조건(14.5, 18.0, 22.3, 26.9%)에서 26$^{\circ}C$를 유지하면서 4 주동안 저장한 후 미곡(통일)에 침해한 곰팡이 및 화학성분의 변화를 1주 간격으로 조사, 분석한 결과를 요약하면 다음과 같다. 1) 표면살균 후에 나타난 곰팡이는 Aspergillius sp., Penicilium sp., Rhizopus sp., 였으며 Asperg-illius sp.가 대부분이었다. 2) 통일쌀에 함유된 Chitin의 함량은 25$\mu\textrm{g}$/g-Dry.wt이었으나 수분의 함량이 높아지고 저장기간이 길어짐에 따라 증가하였다. 29.6%의 수분함량에서 4주간에 생성된 Chitin의 량은 1955$\mu\textrm{g}$/g.Dry.wt이었다. 3) 비환원당의 함량은 수분의 증가와 저장기간이 길어짐에 당라 감소하였다. 4) 지방산도는 수분의 증가와 저장기간이 길어짐에 따라 증가하였다. 5) 이상의 결과로 미곡 저장중 곰팡이 침해에 의하여 민감하게 변하는 Chitin 졍량법이 이용될 수 있을 것으로 사료된다.

• Mycobiology
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• 제44권3호
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• pp.121-130
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• 2016

Recently, the Fusarium genus has been narrowed based upon phylogenetic analyses and a Fusarium-like clade was adopted. The few species of the Fusarium-like clade were moved to new, re-installed or existing genera or provisionally retained as "Fusarium." Only a limited number of reference strains and DNA marker sequences are available for this clade and not much is known about its actual species diversity. Here, we report six strains, preserved by the Belgian fungal culture collection BCCM/IHEM as a Fusarium species, that belong to the Fusarium-like clade. They showed a slow growth and produced pionnotes, typical morphological characteristics of many Fusarium-like species. Multilocus sequencing with comparative sequence analyses in GenBank and phylogenetic analyses, using reference sequences of type material, confirmed that they were indeed member of the Fusarium-like clade. One strain was identified as "Fusarium" ciliatum whereas another strain was identified as Fusicolla merismoides. The four remaining strains were shown to represent a unique phylogenetic lineage in the Fusarium-like clade and were also found morphologically distinct from other members of the Fusarium-like clade. Based upon phylogenetic considerations, a new genus, Pseudofusicolla gen. nov., and a new species, Pseudofusicolla belgica sp. nov., were installed for this lineage. A formal description is provided in this study. Additional sampling will be required to gather isolates other than the historical strains presented in the present study as well as to further reveal the actual species diversity in the Fusarium-like clade.