• Mycobiology
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• v.46 no.3
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• pp.287-295
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• 2018

In this study, we evaluated the effect of different temperatures (10, 20, 30, and $40^{\circ}C$) and relative humidities (RHs; 12, 44, 76, and 98%) on populations of predominant grain fungi (Aspergillus candidus, Aspergillus flavus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum) and the biocontrol activity of Pseudomonas protegens AS15 against aflatoxigenic A. flavus KCCM 60330 in stored rice. Populations of all the tested fungi in inoculated rice grains were significantly enhanced by both increased temperature and RH. Multiple linear regression analysis revealed that one unit increase of temperature resulted in greater effects than that of RH on fungal populations. When rice grains were treated with P. protegens AS15 prior to inoculation with A. flavus KCCM 60330, fungal populations and aflatoxin production in the inoculated grains were significantly reduced compared with the grains untreated with strain AS15 regardless of temperature and RH (except 12% RH for fungal population). In addition, bacterial populations in grains were significantly enhanced with increasing temperature and RH, regardless of bacterial treatment. Higher bacterial populations were detected in biocontrol strain-treated grains than in untreated control grains. To our knowledge, this is the first report showing consistent biocontrol activity of P. protegens against A. flavus population and aflatoxin production in stored rice grains under various environmental conditions of temperature and RH.

• Childhood Kidney Diseases
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• v.23 no.2
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• pp.121-123
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• 2019

Urinary tract infection is common in the pediatric population. The most common causative agents are bacteria, among which Escherichia coli is the most frequent uropathogen. Although fungal urinary tract infection is rare in the healthy pediatric population, it is relatively common among hospitalized patients. Fungus may be isolated from the urine of immunocompromised patients or that of patients with indwelling catheters. The most common cause of funguria is Candida albicans. Although more than 50% of Candida isolates belong to non-albicans Candida, the prevalence of non-albicans candiduria is increasing. Herein, we report a case of community-acquired candiduria in a 4-month-old immunocompetent male infant who had bilateral vesicoureteral reflux and was administered antibiotic prophylaxis. He was diagnosed with urinary tract infection caused by Candida lusitaniae and was managed with fluconazole.

• Journal of Korean Neurosurgical Society
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• v.49 no.3
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• pp.186-189
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• 2011

In recent years the immunocompromised population has increased rapidly to include people with acquired immune deficiency syndrome (AIDS), drug abusers, and transplant patients. Accordingly, the incidence of intracranial fungal infection has increased. Our institution experienced 2 cases of internal carotid artery (ICA) occlusion due to invasion of the cavernous sinus by an intracranial fungal infection. The first case was a 60-year-old man who presented with headache, eye pain, conjunctival injection, right-sided diplopia, and blurred vision. Infected tissues within the frontal and ethmoid sinuses were removed via bifrontal craniotomy and endoscopic sinus surgery through the Caldwell Luc approach. The second case was a 63-year-old woman who developed right-sided facial pain after a tooth extraction. The infection was not controlled despite continuous use of antifungal agents, resulting in death from sepsis. We believe that when intracranial fungal infection is suspected in a patient with orbital symptoms and a focal neurologic deficit, immediate angiographic investigation of possible ICA occlusion is warranted. Aggressive treatment with antifungal agents is the only way to improve prognosis.

• The Korean Journal of Mycology
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• v.13 no.2
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• pp.115-121
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• 1985

An aerial survey for fungal flora in Seoul has been carried out by Petri plate exposure method for a period of one year. A total of 2227 fungal spores appeared in the plates. Of these, Cladosporium was the commonest fungus representing 43.5% of the total spore count followed by Penicillium (15.8%). Alternaria (10.5%), and Aspergillus (3.8%). There were seasonal variations in the prevalence of fungal spores. The occurrence of these fungi was greatly affected by climatic conditions. However, Alternaria appeared to prefer warmer weather. A comparison of fungal population from the outdoor and indoor air was also investigated to support the view that Alternaria is abundant population from the outdoor air and that Cladosporium from the indoor air depending on their availability in the atmosphere.

• Korean Journal of Microbiology
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• v.7 no.1
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• pp.29-40
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• 1969

Two kinds of organic materials, powders of Salicornia and Oryza sativa L. wre added as a source of organic matter to the suspensions of saline soils(soil : water = 1:3) to be 4 per cent of dried saline soil grams. And then, the samples were incubated at $28^{\circ}C$ to improve the decomposition of organic materials by soil microflora. Resutls of this experiment are summarized as followings : 1) The pH of soil suspension showed its highest value on the second or third week after the treatments, which were similar to those of the soil microflora. Results of this experiment are summarized as follwings : 1) The pH of soil suspension showed its highest value on the second ot third week after the treatments, which were similar to those of the soil microflora populations. 2) Salinity increased up to the second week and the highest value of it appeared in the samples which were treated with the powder of Salicornia. In general, the salinity of all samples decreased on the third week after the treatment. The fact was assumed the possibilities of desalination from saline soil by the microbial actions. 3) Soil microflora such as bacteria, actinomycetes and fungi, were determined its populations soil microflora is to act as decomposer in soil. Both of the bacteria and actinomycytes population showed in the third weak after the tratment. In general, 30-years old of saline soil contained microbial population much more than those of 5-year old of saline soil. Salicornia powder favored the increase of both the bacteria and fungal population, and Oryza sativa L. seemed to have been a great role in increase of actinomycetes. Especially, fungal population of the untreated soil suspension contained higher microbial populations more than those of the soils treated with both of the organic materials. 4) Sugar contents of soil suspesions decreased remarkably on the first week after the treatments. 5) The amount of nitrate had similar tendency to those of population changes of soil microflora. Total acidity decreased continuously and the amount of potassium showed its highest value on the third week treatment. However, the amount of phosphorus was determined to be insignificant.

• Korean Journal of Microbiology
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• v.19 no.4
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• pp.154-162
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• 1981

An investigation of the soil microfungal population in the paddy fields of two locations around Seoul was made at four seasons. By the dilution plate method, a total number of propagules of the microfungi pergram of soil was recorded as $10^4$ at the upper layer (0.10cm depth) followed by the middle (10-20cm depth) and the lower layer(20-30 cm depth). The highest number of fungal propagules was $11.0\;{\times}\;10^4$ at the upper layer of the soil collected in autumn. The decreasing tendency of the number of fungal propagules was depend on the increasing depth in paddy fields. Seasonal fluctuation of the fungal population was shown from the highest density of fungal colonies on the plate in autumn season and the lowest one in winter, indicating that the autumn is best season for fungal growth. Generally, the number of the species of Talaromyces in the paddy soils was found to be very high, particularly in autumn, while comparatively low in winter. The highest number of the species of Talaromyces was $6.5\;{\times}\;10^4$ propagules per gram of soil in Yukkog-dong in autumn and the lowest was $0.5\;{\times}\;10^4$ in Shinwon-dong in winter. It is assumed that these fungi grow well also in the warm to the hot seasons.

• Mycobiology
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• v.48 no.5
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• pp.392-398
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• 2020

This study was conducted to understand the dynamics of microbial communities of soil microorganisms, and their distribution and abundance in the indigenous microorganisms (IMOs) manipulated from humus collected from the forest near the crop field. The soil microorganisms originated from humus and artificially cultured microbial-based soil amendments were characterized by molecular and biochemical analyses. The bacterial population (2 × 10⁶~13 × 10⁶ CFU/g sample) was approximately 100-fold abundant than the fungal population (2 × 10⁴~8 × 10⁴ CFU/g sample). The 16S rDNA and ITS sequence analyses showed that the bacterial and fungal communities in humus and IMOs were mainly composed of Bacillus and Pseudomonas, and Trichoderma and Aspergillus species, respectively. Some of the bacterial isolates from the humus and IMOs showed strong inhibitory activity against soil-borne pathogenic fungi Fusarium oxysporum and Sclerotinia sclerotiorum. These bacteria also showed the siderophore production activity as well as phosphate solubilizing activity, which are requisite traits for biological control of plant pathogenic fungi. These results suggest that humus and IMOs could be a useful resource for sustainable agriculture.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.323-327
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• 1992

An experiment was conducted to determine whether there were any apparent differences in the microbial population, colonization pattern and digestion of guinea grass in situ, between cattle and swamp buffalo. Percentage losses in dry matter (DM), nitrogen (N) and neutral detergent fibre (NDF) of guinea grass were significantly (p<0.01) higher when incubated in the rumen of buffalo than in cattle. Buffalo also showed significantly (p<0.05) faster degradation rates than cattle for each grass component (DM, N, DNF). Light microscopy and SEM examination of the incubated grass materials showed that there were no apparent differences in the pattern of bacterial and fungal invasion and colonization of the grass materials between cattle and buffalo. Attachment of bacteria and fungal zoospores on the grass fragments occurred at 15 min after rumen incubation. After 3 h of rumen incubation, dense population of bacteria was observed in the thin-walled mesophyll and parenchyma tissues, whereas root-like fungal rhizoids were observed in both thin-walled and thick-walled cells. By 6 h, eroded zones were apparent in the thin-walled tissues and in thick-walled tissues with profuse rhizoids. After 24. 48 and 72 h of rumen incubation, most thin-walled tissues were degraded leaving mostly the thick-walled tissues. The predominant bacteria were the curved rods resembling Butyrivibrio sp., the thick rods resembling Fibrobacter sp., the diplococcoids resumbling Ruminococcus sp. And spirochetes. Fungi were predominantly those with spherical or oval sporangia. Fusiform sporangia with acuminate apices which resembled Ruminomyces sp. Were of lesser occurrence. Few protozoa were found on the grass fragments at all incubation times.

• The Plant Pathology Journal
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• v.25 no.4
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• pp.303-316
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• 2009

Genetic variation among the base isolates and monosporidial strains derived from these isolates of Tilletia indica- the causal agent of Karnal bunt (KB) in wheat, was analyzed by morphological, growth behaviors and RAPD-ISSR based molecular polymorphism. Genetic make up of fungal cultures vary among each other. The magnitude of variation in KBPN group is less (narrow genetic base) when compared to the other groups KB3, KB9 and JK (broad genetic base) reflecting that variability is a genetically governed process. The generation of new variation with different growth characteristics is not a generalized feature and is totally dependant on the original genetic make-up of the base isolate generating new monosporidial strains. Thus, it can be concluded that monosporidial strains derived from mono-teliosporic isolate, consists of genetically heterogeneous population. The morphological and genetic variability further suggests that the variation in T. indica strains is predominantly derived through the genetic rearrangements through para sexual means.

• Korean Journal of Microbiology
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• v.22 no.3
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• pp.157-165
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• 1984

Seasonal and spatial variations in propagule numbers of Trichoderma species were investigated every other month for one year in deciduous and coniferous forest soils and evaluated the relationships of Trichoderma spp. populations to soil environmental factors. The total population of Trichoderma spp. increased until summer and then declined until winter. The yearly mean frequency of Trichoderma spp. exceeded 1.4% of total fungal propagules in two sites. Decreases of absolute an relative propagule numbers of Trichoderma spp. with increasing soil depth were found and variation in Trichoderma spp. propagules caused by differences in soil depth ($0{\sim}50cm$) was greater than that caused by differences in sampling time. The most common species occurring in two sites was T. viride, followed by T. polysporum, T. koningii, and T. hamatum. Individual species of Trichoderma showed diferent abundance trend in accordance with sampling time. T. viride was dorminant from spring to autumn, while T. polysporum dominated over the other speicies in winter. Variations in propagule number of Trichoderma sppp. were principally mediated by the actions of biotic environmental factors rather than by the direct effects of abiotic factors. In multiple-regression analyses, 48% of the total vaiation in Trichoderma spp. propagules in deciduous site could be accounted for by total fungal propagules and soil CMCase actvity. In coniferous site, 65% of total variation could be accounted for by total fungal and bacterial propagules, moisture content and organic carbon content.