• Mycobiology
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• 제51권2호
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• pp.87-93
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• 2023

The fungal strain belonging to the genus Monochaetia of the family Sporocadaceae was isolated from hairy long-horned toad beetle (Moechotypa diphysis) during the screening of microfungi associated with insects from Gangwon Province, Korea. The strain KNUF-6L2F produced white, light brown to dirty black surface, and olivaceous green colonies with the higher growth, while the closest strain M. ilicis KUMCC 15-0520^T were light brown to brown, and M. schimae SAUCC 212201^T light brown to brown toward center. The strain KNUF-6L2F produced shorter (5.7-14.0 ㎛) apical appendages than M. ilicis (6.0-24.0 ㎛), but similar to M. schimae (7.0-12.5 ㎛). Three median cells of KNUF-6L2F were light brown to olivaceous green, whereas brown and olivaceous cells were observed from M. ilicis and M. schimae, respectively. And the strain KNUF-6L2F produced larger conidiogenous cells than M. ilicis and M. schimae. Additionally, phylogenetic analyses based on molecular datasets of internal transcribed spacer (ITS) regions, translation elongation factor 1-alpha (TEF1α), and β-tubulin (TUB2) genes corroborated the strain's originality. Thus, the strain is different from other known Monochaetia species, according to molecular phylogeny and morophology, hence we suggested the new species Monochaetia mediana sp. nov. and provided a descriptive illustration.

• 식물병연구
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• 제28권4호
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• pp.209-220
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• 2022

Charcoal canker of oak, which has recently increased in southern Iran, could pose a serious threat to the entire forest ecosystem in the near future. In addition, it seems that climate change and its consequences, such as drought in the southern regions of Iran, have exacerbated this phenomenon. Consequently, the objective of this study was to identify the fungal pathogens that could cause charcoal canker disease in the oak forests of South Zagros. It was also sought to find associations between changes in the occurrence/exacerbation of charcoal canker disease under non and intense drought stress in non-inoculated or inoculated Quercus brantii seedlings. In total, 120 isolates were obtained from eight oak forests located in the Zagros Mountains of Southern Iran, Kohgiluyeh & Boyer-Ahmad and Fars provinces, which were classified as Biscogniauxia mediterranea based on morphological assessment. Subsequently, molecular assay confirmed the result by phylogenetic inference of internal transcribed spacer-rDNA regions, α-actin, and β-tubulin genes. The results of the pathogenicity test showed that the response of isolates of B. mediterranea (Iran-G1 and Iran-M70) was varied in different environments for the measured necrotic lesion length. In comparison with the control moisture treatments (non-stress), the necrotic lesion length in inoculated treatments increased under intense drought stress. In general, inoculated oak seedlings' exposure to water-deficient stress by the pathogen of B. mediterranea could affect the spread/severity of the charcoal canker disease.

• ALGAE
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• 제38권2호
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• pp.93-110
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• 2023

Progress in phylogenomic analysis has led to a considerable re-evaluation of former cyanobacterial system, with many new taxa being established at different nomenclatural levels. The family Geminocystaceae is among cyanobacterial taxa recently described on the basis of polyphasic approach. Within this family, there are six genera: Geminocystis, Cyanobacterium, Geminobacterium, Annamia, Picocyanobacterium, and Microcrocis. The genus Geminocystis previously encompassed two species: G. herdmanii and G. papuanica. Herein, a new species G. urbisnovae was proposed under the provision of the International Code of Nomenclature for algae, fungi, and plants (ICN). Polyphasic analysis was performed for five strains from the CALU culture collection (St. Petersburg State University, Russian Federation), and they were assigned to the genus Geminocystis in accordance with high 16S rRNA gene similarity to existing species, as well as because of proximity to these species on the phylogenetic trees reconstructed with RaxML and Bayes methods. Plausibility of their assignment to a separate species of the genus Geminocystis was substantiated with smaller cell size; stenohaline freshwater ecotype; capability to complementary chromatic adaptation of second type (CA2); distinct 16S rRNA gene clustering; sequences and folding of D1-D1' and B box domains of the 16S-23S internal transcribed spacer region. The second objective pursued by this communication was to provide a survey of the family Geminocystaceae. The overall assessment was that, despite attention of many researchers, this cyanobacterial family has been understudied and, especially in the case of the crucially important genus Cyanobacterium, taxonomically problematic.

• Journal of Microbiology and Biotechnology
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• 제33권9호
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• pp.1238-1249
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• 2023

In this study, we sought to investigate the production and optimization of biosurfactants by soil fungi isolated from petroleum oil-contaminated soil in Saudi Arabia. Forty-four fungal isolates were isolated from ten petroleum oil-contaminated soil samples. All isolates were identified using the internal transcribed spacer (ITS) region, and biosurfactant screening showed that thirty-nine of the isolates were positive. Aspergillus niger SA1 was the highest biosurfactant producer, demonstrating surface tension, drop collapsing, oil displacement, and an emulsification index (E₂₄) of 35.8 mN/m, 0.55 cm, 6.7 cm, and 70%, respectively. This isolate was therefore selected for biosurfactant optimization using the Fit Group model. The biosurfactant yield was increased 1.22 times higher than in the nonoptimized medium (8.02 g/l) under conditions of pH 6, temperature 35℃, waste frying oil (5.5 g), agitation rate of 200 rpm, and an incubation period of 7 days. Model significance and fitness analysis had an RMSE score of 0.852 and a p-value of 0.0016. The biosurfactant activities were surface tension (35.8 mN/m), drop collapsing (0.7 cm), oil displacement (4.5 cm), and E₂₄ (65.0%). The time course of biosurfactant production was a growth-associated phase. The main outputs of the mathematical model for biomass yield were Yx/s (1.18), and µ_max (0.0306) for biosurfactant yield was Y_p/s (1.87) and Y_p/x (2.51); for waste frying oil consumption the So was 55 g/l, and Ke was 2.56. To verify the model's accuracy, percentage errors between biomass and biosurfactant yields were determined by experimental work and calculated using model equations. The average error of biomass yield was 2.68%, and the average error percentage of biosurfactant yield was 3.39%.

• 한국식품저장유통학회지
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• 제30권1호
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• pp.28-41
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• 2023

Non-aflatoxigenic Aspergillus oryzae and aflatoxigenic A. flavus cannot be clearly identified by partial sequencing of the internal transcribed spacer (ITS) and 18S ribosomal ribonucleic acid (18S rRNA) regions. This study aimed to compare the accuracy among three aflatoxin detection methods using ultra-performance liquid chromatography (UPLC), high-performance liquid chromatography (HPLC), and an enzyme-linked immunosorbent assay (ELISA) kit and to select the non-aflatoxigenic Aspergillus sp. isolated from soybean paste. All analytical methods were suitable according to the international standards of Codex Alimentarius FAO-WHO (CODEX) or the Ministry of Food and Drug Safety (MFDS). UPLC exhibited the best of limit of detection (LOD) and limit of quantification (LOQ). Based on UPLC, HPLC, and the ELISA kit assay, the P5 and P7 strains isolated from soybean paste had 1,663.49, 1,468.12, and >20 ㎍/kg and 1,470.08, 1,056.73, and >20 ㎍/kg, respectively, detected and re-identified as A. flavus. In contrast, the P3 and P4 strains (A. oryzae), which were detected below the MFDS standards in all assays, were confirmed as non-aflatoxigenic fungi. Among the methods evaluated for quantitative analysis of aflatoxin, UPLC and HPLC are superior in terms of accuracy, and the ELISA kit rapidly detects low concentrations of aflatoxin. Furthermore, this study demonstrates that any Aspergillus sp. isolated for use as a fermentation starter should be analyzed for potential aflatoxin production using UPLC and HPLC for accurate quantitative analysis or ELISA for the rapid detection of low-level concentrations of aflatoxin.

• International Journal of Industrial Entomology and Biomaterials
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• 제48권1호
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• pp.42-47
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• 2024

The value of silkworms as functional health food materials has increased, as has the interest in its disease control for stable production, and in the economic value of entomopathogenic microorganisms. In this study, we isolated and identified disease-causing fungi from white muscardine silkworms, and confirmed whether this strain could produce white muscardine silkworms. For the analysis of the cause of white muscardine disease in the infected silkworms, the fungi and prokaryotes causing the disease were identified, isolated, and identified using metagenome analysis. Metagenomic analysis detected a large amount of the fungus Metarhizium rileyi in silkworms, and a large amount of the bacterium Enterococcus mundtii, which was presumed to be the causative agent of the disease. For accurate identification of the fungi, these were purified by culture medium, and sequencing and phylogenetic tree analyses were performed using an internal transcribed spacer. As a result, M. rileyi, Cladosporium cladosporioides, and C. tenuissimum were identified. In general, M. rileyi is known to form green conidia, but in this study, white-yellow conidia were formed, indicating that the exact causative agent of the fungal disease cannot be estimated by diagnosing the symptoms. Thus, a diagnostic method is necessary for the continuously collection of required pathogens, and identifying their morphological and genetic characteristics.

• 한국균학회지
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• 제51권3호
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• pp.251-257
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• 2023

독도에 자생하는 식물인 왕호장근(Fallopia sachalinensis)의 근권 토양에서 다양한 균류를 분리하였다. 분리균들의 형태적 특징과 rDNA-ITS와 LSU 또는 beta-tubulin 영역 분석을 통한 분자적 특징을 확인하였다. 그 결과 기존에 국내에 보고되지 않은 Penicillium striatisporum, Gongronella sichuanensis 종들이 분리되어 이를 보고하고자 한다. 미기록 종들의 형태적 특징과 분자적특징을 본문에 기술하였다.

• 한국균학회지
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• 제51권3호
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• pp.179-190
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• 2023

Grapevine downy mildew, caused by Plasmopara viticola, significantly damages vineyards and is one of the most devastating diseases affecting cultivated grapes worldwide. In this study, we characterized the phenotypic and molecular traits of 11 P. viticola isolates from four grape-growing regions in South Korea. Additionally, we investigated the diversity of pathogenicity among these isolates and conducted an assay to evaluate the response of grape cultivars to P. viticola infection. Lemon-shaped sporangia were identified in the collected isolates, which released zoospores into the suspension at room temperature. Within a few hours of inoculation, the zoospores developed germ tubes. We tested 11 P. viticola isolates for pathogenicity in 845 grape cultivars to screen for grape host resistance to downy mildew infection. Among the tested isolates, JN-9 showed the highest virulence. Grape cultivars displayed varying phenotypic reactions to P. viticola infection: approximately 7% were highly susceptible, 41% were susceptible, 20% were moderately susceptible, 8% were resistant, and 24% exhibited extreme resistance. Phylogenetic analysis based on four genomic regions (internal transcribed spacer 1 [ITS1], actin, beta-tubulin, and cytochrome c oxidase II) revealed a close evolutionary relationship among all the Korean isolates, forming a single monophyletic lineage. Notably, these isolates showed greater similarity to European isolates than to American isolates. This comprehensive study contributes to a deeper understanding of the identity and behavior of P. viticola, which is crucial for developing effective resistance strategies against this pathogen in grape cultivars cultivated in South Korea.

• International Journal of Industrial Entomology and Biomaterials
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• 제48권3호
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• pp.124-138
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• 2024

The International Union for Conservation of Nature and the Korean Red Data Book both categorize the dragon swallowtail Sericinus montela Grey, 1852 (Lepidoptera: Papilionidae) as a vulnerable insect. In South Korea, the main reason for this categorization is habitat destruction and deterioration, along with limited distribution mainly to the eastern region of South Korea, particularly to Gangwon-do and Gyeongsangbuk-do. Considering much of the information is older than ten years the renewed survey to estimate distributional stability is required, particularly under global warming. In addition, the population genetic diversity and isolation of S. montela, which is important information when seeking to evaluate its vulnerability, is not yet known. In this study, we visited 38 habitable sites, consisted of 15 sites with the previous record for the sightings of the species and 23 sites without such record. Moreover, nuclear ribosomal internal transcribed spacer region was sequenced for 56 individuals collected from seven sites. We observed S. montela at 20 sites, consisted of 11 recorded and 9 new sites in seven provinces, excluding Jeollanam-do and Jeju-do. Finding of the species in 9 new sites and location of the 4 in western region, which has a rare previous record are promising. However, failure to observe in 4 recorded sites and an extremely low observed number in new sites (5.3 vs. 17.6 individuals per site on average) is not optimistic. Population genetic data partially corroborate with the field observation data, showing that the populations in western region have lower genetic diversity and intermittent genetic isolation compared to those in eastern region. Taken these together, we suggest that S. montela should be remained as a vulnerable insect. However, more extensive field monitoring and co-dominant molecular data are required to verify this conclusion.

• 한국균학회지
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• 제31권3호
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• pp.121-128
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• 2003

국내 유통균주에 대한 Phellinus속의 분류체계를 확립하고 종간구별을 위한 신속동정법을 개발하기 위해 계통학적 정보를 지니고 있는 ITS1, 5.8S rRNA및 ITS2부위의 염기서열을 밝히고 ITS1과 ITS2 부위의 다양한 염기서열을 이용하여 종 특이적인 유전자 탐침을 개발하였다. 본 연구에서 조사된 바에 의하면, 상황버섯으로 시판되고 있는 국내유통균주는 총 9균주로서 P. pini가 4종, P. baumii가 3종, P. igniarius와 P. linteus가 각각 1종으로 확인되었으며 P. gilvus은 조사되지 알았다. 그 중 P. pini는 대부분 중국에서 수입된 제품이었고 P. igniarius를 포함한 P. baumii는 주로 북한산 제품으로 조사되었다. 한편 P. linteus와 P. baumii는 변이가 높은 ITS1 , ITS2 부위에서도 다른 종에 비하여 높은 상동성을 나타내어 종 특이적인 유전자 탐침이 유효하지 않은 반면에 P. igniarius, P. pini, P. gilvus종에 대한 detection primer로 각각 IF1-IR3, PF1-PF3, GF2-FR4 primer는 유전자 탐침이 유효함을 확인하였다. 유연관계가 아주 가까운 P. linteus와 P. baumii에 대한 정확한 분석을 위해서는 변이가 심한 ITS 부위와 보존성이 높은 18S rDNA 부위의 염기서열을 함께 분석, 비교하여야 가능하리라 사료된다.