1.First Report of the Ash Dieback Pathogen Hymenoscyphus fraxineus in Korea.
Jae Gu HAN ; Bhushan SHRESTHA ; Tsuyoshi HOSOYA ; Kang Hyo LEE ; Gi Ho SUNG ; Hyeon Dong SHIN
Mycobiology 2014;42(4):391-396
In the past two decades, European ash trees (Fraxinus spp.) have been severely damaged due to ash dieback disease, which is caused by the fungal species Hymenoscyphus fraxineus (Chalara fraxinea in the anamorphic stage). Recent molecular phylogenetic and population genetic studies have suggested that this fungus has been introduced from Asia to Europe. During a fungal survey in Korea, H. fraxineus-like apothecia were collected from fallen leaves, rachises, and petioles of Korean ash and Manchurian ash trees. The morphological and ecological traits of these materials are described with the internal transcribed spacer rDNA sequence comparison of H. fraxineus strains collected from Korea, China and Japan.
Asia
;
China
;
DNA, Ribosomal
;
Europe
;
Fraxinus
;
Fungi
;
Japan
;
Korea
2.Virulence of Entomopathogenic Fungi Metarhizium anisopliae and Paecilomyces fumosoroseus for the Microbial Control of Spodoptera exigua.
Ji Hee HAN ; Byung Rae JIN ; Jeong Jun KIM ; Sang Yeob LEE
Mycobiology 2014;42(4):385-390
The beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) is difficult to control using chemical insecticides because of the development of insecticide resistance. Several pest control agents are used to control the beet armyworm. Entomopathogenic fungi are one of the candidates for eco-friendly pest control instead of chemical control agents. In this study, among various entomopathogenic fungal strains isolated from soil two isolates were selected as high virulence pathogens against larva of beet armyworm. Control efficacy of fungal conidia was influenced by conidia concentration, temperature, and relative humidity (RH). The isolates Metarhizium anisopliae FT83 showed 100% cumulative mortality against second instar larvae of S. exigua 3 days after treatment at 1 x 10(7) conidia/mL and Paecilomyces fumosoroseus FG340 caused 100% mortality 6 days after treatment at 1 x 10(4) conidia/mL. Both M. anisopliae FT83 and P. fumosoroseus FG340 effectively controlled the moth at 20~30degrees C. M. anisopliae FT83 was significantly affected mortality by RH: mortality was 86.7% at 85% RH and 13.4% at 45% RH. P. fumosoroseus FG340 showed high mortality as 90% at 45% RH and 100% at 75% RH 6 days after conidia treatments. These results suggest that P. fumosoroseus FG340 and M. anisopliae FT83 have high potential to develop as a biocontrol agent against the beet armyworm.
Beta vulgaris
;
Fungi*
;
Humidity
;
Insecticide Resistance
;
Insecticides
;
Larva
;
Metarhizium*
;
Mortality
;
Moths
;
Paecilomyces*
;
Pest Control
;
Soil
;
Spodoptera*
;
Spores, Fungal
;
Virulence*
3.Control of Root Rot and Wilt Diseases of Roselle under Field Conditions.
Naglaa HASSAN ; Mohsen Mohamed ELSHARKAWY ; Masafumi SHIMIZU ; Mitsuro HYAKUMACHI
Mycobiology 2014;42(4):376-384
Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle.
Antioxidants
;
Ascorbic Acid
;
Bacillus
;
Biological Control Agents
;
Copper
;
Fusarium
;
Hibiscus
;
Incidence
;
Salicylic Acid
4.Bioconversion of Ginsenosides from Red Ginseng Extract Using Candida allociferrii JNO301 Isolated from Meju.
Sulhee LEE ; Yong Hun LEE ; Jung Min PARK ; Dong Hoon BAI ; Jae Kweon JANG ; Young Seo PARK
Mycobiology 2014;42(4):368-375
Red ginseng (Panax ginseng), a Korean traditional medicinal plant, contains a variety of ginsenosides as major functional components. It is necessary to remove sugar moieties from the major ginsenosides, which have a lower absorption rate into the intestine, to obtain the aglycone form. To screen for microorganisms showing bioconversion activity for ginsenosides from red ginseng, 50 yeast strains were isolated from Korean traditional meju (a starter culture made with soybean and wheat flour for the fermentation of soybean paste). Twenty strains in which a black zone formed around the colony on esculin-yeast malt agar plates were screened first, and among them 5 strains having high beta-glucosidase activity on p-nitrophenyl-beta-D-glucopyranoside as a substrate were then selected. Strain JNO301 was finally chosen as a bioconverting strain in this study on the basis of its high bioconversion activity for red ginseng extract as determined by thin-layer chromatography (TLC) analysis. The selected bioconversion strain was identified as Candida allociferrii JNO301 based on the nucleotide sequence analysis of the 18S rRNA gene. The optimum temperature and pH for the cell growth were 20~30degrees C and pH 5~8, respectively. TLC analysis confirmed that C. allociferrii JNO301 converted ginsenoside Rb1 into Rd and then into F2, Rb2 into compound O, Rc into compound Mc1, and Rf into Rh1. Quantitative analysis using high-performance liquid chromatography showed that bioconversion of red ginseng extract resulted in an increase of 2.73, 3.32, 33.87, 16, and 5.48 fold in the concentration of Rd, F2, compound O, compound Mc1, and Rh1, respectively.
Absorption
;
Agar
;
Base Sequence
;
beta-Glucosidase
;
Candida*
;
Chromatography, Liquid
;
Chromatography, Thin Layer
;
Fermentation
;
Flour
;
Genes, rRNA
;
Ginsenosides*
;
Hydrogen-Ion Concentration
;
Intestines
;
Panax*
;
Plants, Medicinal
;
Soybeans
;
Triticum
;
Yeasts
5.Identification of Wild Yeast Strains and Analysis of Their beta-Glucan and Glutathione Levels for Use in Makgeolli Brewing.
Sun Hee KANG ; Hye Ryun KIM ; Jae Ho KIM ; Byung Hak AHN ; Tae Wan KIM ; Jang Eun LEE
Mycobiology 2014;42(4):361-367
Makgeolli, also known as Takju, is a non-filtered traditional Korean alcoholic beverage that contains various floating matter, including yeast cells, which contributes to its high physiological functionality. In the present study, we assessed the levels of beta-glucan and glutathione in various yeast strains isolated from traditional Korean Nuruk and selected a beta-glucan- and glutathione-rich yeast strain to add value to Makgeolli by enhancing its physiological functionality through increased levels of these compounds. Yeast beta-glucan levels ranged from 6.26% to 32.69% (dry basis) and were strongly species-dependent. Dried Saccharomyces cerevisiae isolated from Nuruk contained 25.53 microg/mg glutathione, 0.70 microg/mg oxidized glutathione, and 11.69 microg/g and 47.85 microg/g spermidine and L-ornithine monohydrochloride, respectively. To produce functional Makgeolli, a beta-glucan- and glutathione-rich yeast strain was selected in a screening analysis. Makgeolli fermented with the selected yeast strain contained higher beta-glucan and glutathione levels than commercial Makgeolli. Using the selected yeast strain to produce Makgeolli with high beta-glucan and glutathione content may enable the production of functional Makgeolli.
Alcoholic Beverages
;
Glutathione Disulfide
;
Glutathione*
;
Mass Screening
;
Saccharomyces cerevisiae
;
Spermidine
;
Yeasts*
6.Metabolite Profiling during Fermentation of Makgeolli by the Wild Yeast Strain Saccharomyces cerevisiae Y98-5.
Hye Ryun KIM ; Jae Ho KIM ; Byung Hak AHN ; Dong Hoon BAI
Mycobiology 2014;42(4):353-360
Makgeolli is a traditional Korean alcoholic beverage. The flavor of makgeolli is primarily determined by metabolic products such as free sugars, amino acids, organic acids, and aromatic compounds, which are produced during the fermentation of raw materials by molds and yeasts present in nuruk, a Korean fermentation starter. In this study, makgeolli was brewed using the wild yeast strain Saccharomyces cerevisiae Y98-5, and temporal changes in the metabolites during fermentation were analyzed by ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. The resultant data were analyzed by partial least squares-discriminant analysis (PLS-DA). Various metabolites, including amino acids, organic acids, sugar alcohols, small peptides, and nucleosides, were obviously altered by increasing the fermentation period. Changes in these metabolites allowed us to distinguish among makgeolli samples with different fermentation periods (1, 2, 3, 6, 7, and 8 days) on a PLS-DA score plot. In the makgeolli brewed in this study, the amounts of tyrosine (463.13 microg/mL) and leucine (362.77 microg/mL) were high. Therefore, our results indicate that monitoring the changes in metabolites during makgeolli fermentation might be important for brewing makgeolli with good nutritional quality.
Alcoholic Beverages
;
Amino Acids
;
Amino Sugars
;
Fermentation*
;
Fungi
;
Leucine
;
Mass Spectrometry
;
Nucleosides
;
Nutritive Value
;
Peptides
;
Saccharomyces cerevisiae*
;
Sugar Acids
;
Tyrosine
;
Yeasts*
7.Influence of Additives on the Yield and Pathogenicity of Conidia Produced by Solid State Cultivation of an Isaria javanica Isolate.
Jeong Jun KIM ; Ling XIE ; Ji Hee HAN ; Sang Yeob LEE
Mycobiology 2014;42(4):346-352
Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of Bemisia tabaci worldwide, because of its increased resistance to some insecticide groups. As an alternative control agent, we selected an Isaria javanica isolate as a candidate for the development of a mycopesticide against the Q biotype of sweet potato whitefly. To select optimal mass production media for solid-state fermentation, we compared the production yield and virulence of conidia between 2 substrates (barley and brown rice), and we also compared the effects of various additives on conidia production and virulence. Barley was a better substrate for conidia production, producing 3.43 x 10(10) conidia/g, compared with 3.05 x 10(10) conidia/g for brown rice. The addition of 2% CaCO3 + 2% CaSO4 to barley significantly increased conidia production. Addition of yeast extract, casein, or gluten also improved conidia production on barley. Gluten addition (3% and 1.32%) to brown rice improved conidia production by 14 and 6 times, respectively, relative to brown rice without additives. Conidia cultivated on barley produced a mortality rate of 62% in the sweet potato whitefly after 4-day treatment, compared with 53% for conidia cultivated on brown rice. The amendment of solid substrate cultivation with additives changed the virulence of the conidia produced; the median lethal time (LT50) was shorter for conidia produced on barley and brown rice with added yeast extract (1.32% and 3%, respectively), KNO3 (0.6% and 1%), or gluten (1.32% and 3%) compared with conidia produced on substrates without additives.
Caseins
;
Fermentation
;
Glutens
;
Hemiptera
;
Hordeum
;
Ipomoea batatas
;
Mortality
;
Spores, Fungal*
;
Tobacco
;
Virulence*
;
Yeasts
8.Morphology and Molecular Characterization of Alternaria argyranthemi on Chrysanthemum coronarium in China.
Huan LUO ; Zhen Zhou XIA ; Yun Yun CHEN ; Yi ZHOU ; Jian Xin DENG
Mycobiology 2018;46(3):278-282
Chrysanthemum coronarium is an economically important plant in Asia, and used medicinally, ornamentally and as a vegetable. In April 2017, leaf spot disease on C. coronarium was observed in Shiyan, Hubei, China. A single-spore isolate was obtained and identified based on morphology and sequence analysis using four regions (rDNA ITS, GAPDH, EF-1α, and RPB2). The results indicated that the fungus is Alternaria argyranthemi. The pathogenicity tests revealed that the species could cause severe leaf spot and blight disease on the host. This is the first report of leaf spot disease on C. coronarium caused by A. argyranthemi in the world, which is also a new record of Alternaria species in China.
Alternaria*
;
Asia
;
Asteraceae
;
China*
;
Chrysanthemum*
;
Fungi
;
Plants
;
Sequence Analysis
;
Vegetables
;
Virulence
9.Investigation of Filamentous Fungi Producing Safe, Functional Water-Soluble Pigments.
Young Mok HEO ; Kyeongwon KIM ; Sun Lul KWON ; Joorim NA ; Hanbyul LEE ; Seokyoon JANG ; Chul Hwan KIM ; Jinho JUNG ; Jae Jin KIM
Mycobiology 2018;46(3):269-277
The production of water-soluble pigments by fungal strains indigenous to South Korea was investigated to find those that are highly productive in submerged culture. Among 113 candidates, 34 strains that colored the inoculated potato dextrose agar medium were selected. They were cultured in potato dextrose broth and extracted with ethanol. The productivity, functionality (radical-scavenging activities), and color information (CIELAB values) of the pigment extracts were measured. Five species produced intense yellowish pigments, and two produced intense reddish pigments that ranked the highest in terms of absorbance units produced per day. The pigment extracts of Penicillium miczynskii, Sanghuangporus baumii, Trichoderma sp. 1, and Trichoderma afroharzianum exhibited high radical-scavenging activity. However, the S. baumii extract showed moderate toxicity in the acute toxicity test, which limits the industrial application of this pigment. In conclusion, P. miczynskii KUC1721, Trichoderma sp. 1 KUC1716, and T. afroharzianum KUC21213 were the best fungal candidates to be industrial producers of safe, functional water-soluble pigments.
Agar
;
Colorimetry
;
Efficiency
;
Ethanol
;
Fungi*
;
Glucose
;
Korea
;
Penicillium
;
Solanum tuberosum
;
Toxicity Tests, Acute
;
Trichoderma
10.Discovery of Two Chrysosporium Species with Keratinolytic Activity from Field Soil in Korea.
Sun Kumar GURUNG ; Mahesh ADHIKARI ; Sang Woo KIM ; Setu BAZIE ; Hyun Seung KIM ; Hyun Goo LEE ; San KOSOL ; Hyang Burm LEE ; Youn Su LEE
Mycobiology 2018;46(3):260-268
In an ongoing survey of Korean indigenous fungi, two fungal strains (KNU16-74 and KNU16-99) belonging to the genus Chrysosporium were isolated from field soil in Gyeongnam, Korea. Morphological characterization and phylogenetic analysis using sequence of the internal transcribed spacer regions were carried out to confirm its precise identification. These strains were identified as Chrysosporium indicum (KNU16-74) and Chrysosporium fluviale (KNU16-99). To examine the keratin degradation efficiency of these two fungal species, human hair strands were incubated with fungus culture. Results revealed that these two fungal species have the ability to degrade keratin substrate. This is the first report of these two species in Korea.
Chrysosporium*
;
Fungi
;
Hair
;
Humans
;
Korea*
;
Soil*