• 한국생태학회:학술대회논문집
• /
• 2002.08a
• /
• pp.93-100
• /
• 2002

Dynamics of certain $N_2$fixing bacteria such as Rhizobium, Azospirillum and Azotobactor, nodule number in dominant legume, Atylosia trinervia, P-solubilizing bacteria, actinomycetes and fungi were studied in unburned and burned site of natural grassland, southern India. Population of $N_2$- fixing bacteria, P-solubilizing bacteria, fungi and nodule number in legume increased significantly in burned sites. On the other hand, the actinomycetes population remained unchanged. Thirty six species of fungi with tricalcium phosphate solubilizing ability were recorded. The most efficient P-solubilizing fungi recognised in the soils of the study sites are Absidia ramosa, Gongronella butlerii, Mortieralla spinosa, Mucor racemosus, Rhizopus nigricans, R. stolonifer, R. oryzae, Aspergillus fumigatus, A. nidulans, A. niger Theilavia terricola and Cheatomium lunasporium.

• The Korean Journal of Ecology
• /
• v.25 no.4
• /
• pp.227-234
• /
• 2002

Dynamics of certain $N_2$ fixing bacteria such as Rhizobium, Azospirillum and Azotobactor, nodule number in dominant legume, Atylosia trinervia, P-solubilizing bacteria, actinomycetes and fungi were studied in unburned and burned site of natural grassland, southern India. Population of $N_2$ - fixing bacteria, P-solubilizing bacteria, fungi and nodule number in legume increased significantly in burned sites. On the other hand, the actino-mycetes population remained unchanged. Thirty six species of fungi with tricalcium phosphate solubilizing ability were recorded. The most efficient P-solubilizing fungi recognised in the soils of the study sites are Absidia ramosa, Gongronella butlerii, Mortieralla spinosa, Mucor racemosus, Rhizopus nigricans, R. stolonifer, R. oryzae, Aspergillus fumigatus, A. nidulans, A. niger, Theilavia terricola and Cheatomium lunasporium.

• Journal of Environmental Health Sciences
• /
• v.33 no.2 s.95
• /
• pp.104-114
• /
• 2007

This study evaluated the airborne concentrations of bacteria, Gram-negative bacteria, and fungi in waiting rooms, wards, and outdoors, according to time and particle size between October 17 and November 28, 2003. The geometric mean number of airborne bacteria was highest in the morning. The more people there were, the higher was the total bacteria concentration. The concentration of fungi was also highest in the morning. Temperature and relative humidity affected the concentrations of fungi significantly (p<0.05). This study found relationships between microorganism concentrations and (actors such as time, place, temperature, humidity, ventilation, and number of people. Therefore, to manage the pollution resulting from airborne microorganisms, each time, place, and environmental factor should be examined periodically, and the number, size, and movement of airborne microorganisms should be evaluated.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.18 no.3
• /
• pp.187-194
• /
• 1998

This study was conducted to investigate the effect of antagonistic bacteria and pathogenic fungi on growth and yields of white clover(Trifo1iurn repens L.) in continuous cropping soil(CCS) and non-continuous cropping soil(NCCS). The gowth experiment of white clover was conducted at pots in a vinyl house. White clover was established by seeding into pots of 12 cm in diameter and 9 cm in depth containing 1:l mixture of soil and vermiculite with antagonistic bacteria and pathogenic fungi. In dark culture experiment, white clover lived longer in treatment of antagonistic bacteria than in treatment of control, but lived shorter in CCS than in NCCS. Dry weight of white clover was increased by the inoculation of the antagonistic bacteria(p< 0.05), but decreased by the inoculation of the pathogenic fungi(p< 0.05) both CCS and NCCS. In conclusion, bacterization of white clover with antagonistic bacteria enhances the growth and yield of white clover.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.16 no.2
• /
• pp.101-109
• /
• 2006

The objective of this study is to provide fundamental data for pertinent management of indoor air quality through investigating the size-based characteristics of bioaerosol distributed in the general hospital. Measurement sites are main lobby, ICU, ward and laboratory and total five times were sampled with six-stage cascade impactor. Based on the result of this study, concentrations of airborne bacteria and fungi were the highest in main lobby as followed by an order of ward, ICU and laboratory. Concentrations of airborne bacteria was generally higher than those of airborne fungi and the ratio of indoor and outdoor concentration of both exceeded 1.0 in all the measurement sites of the general hospital. The predominant genera of airborne bacteria identified in the general hospital were Staphylococcus spp.(50%), Micrococcus spp.(15-20%), Corynebacterium spp.(5-20%), and Bacillus spp.(5-15%). On the other hand, the predominant genera of airborne fungi identified in the general hospital were Cladosporium spp.(30%), Penicillium spp.(20-25%), Aspergillus spp.(15-20%), and Alternaria spp.(10-20%). In regard to size distribution of bioaerosol, the detection rate was generally highest on 5 stage($1.1-2.1{\mu}m$) for airborne bacteria and on 1 stage(>$7.0{\mu}m$) for airborne fungi. Cleanliness of facilities in the general hospital and condition of HVAC system should be monitored regularly to prevent indoor air contamination by airborne microorganisms.

• The Plant Pathology Journal
• /
• v.24 no.1
• /
• pp.74-79
• /
• 2008

This research was conducted to evaluate fungal and bacterial populations in unhulled and brown rice under indoor storage conditions, and to examine the relationship between microbial populations and environmental conditions such as temperature and relative humidity. The temperature and relative humidity of the storage room ranged from $22.6^{\circ}C\;to\;27.0^{\circ}C$ and 23.3% to 44.2%, respectively. Total fungal and bacterial populations remained relatively stable over the storage period. Predominant fungi included Aspergillus candidus, A. flavus, A. fumigatus, and Penicillium spp.; the predominant bacteria were Bacillus, Microbacterium, Sphingomonas, and Methylobacterium spp. Total fungi and bacteria were not significantly correlated with either unhulled (r=0.448, P=0.372) or brown (r=0.466, P=0.351) rice. In unhulled rice, total fungi showed positive correlations with total Aspergillus (r=0.994, P<0.001) and total Penicillium (r=0.906, P<0.05); A. flavus was positively correlated with total Aspergillus (r=0.913, P<0.05) and total fungi (r=0.868, P<0.05). In brown rice, Bacillus spp. was also positively correlated with total bacteria (r=0.998, P<0.001). Mean temperature was negatively correlated with A. candidus (r=-0.852, P<0.05) and total fungi (r=-0.961, P<0.01), and mean relative humidity was positively correlated with total Penicillium spp.(r=0.884, P<0.05) in brown rice. Hence these results could provide basic information on the fungal and bacterial populations in unhulled and brown rice stored under room conditions, and on the effect of environmental conditions on the populations of fungi and bacteria, especially Aspergillus and Penicillium spp.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.1
• /
• pp.70-74
• /
• 2007

An in vitro study was carried out to investigate the differences in rumen microbes and fiber degradation capacity between sheep and goats. Three local male sheep and three Inner Mongolia male cashmere goats (aged 1.5 to 2 years; weight 25.0 to 32.0 kg) were each fitted with a permanent rumen cannula used to provide rumen fluid. Cycloheximide was used to eliminate rumen anaerobic fungi. The results showed that the quantities of fungal zoospores in the culture fluid of the control group were significantly greater in the sheep than in the goats; however, bacteria and protozoa counts were significantly higher in goats than in sheep. The digestibility of straw dry matter did not differ significantly between the two species before elimination of fungi, but tended to be higher for sheep (55.4%) than for goats (53.3%). The results also indicated that bacteria counts increased significantly after elimination of anaerobic fungi; however, the digestibility of straw dry matter significantly decreased by 12.1% and 8.6% for sheep and goats respectively. This indicated that the anaerobic fungi of the rumen played an important role in degradation of fiber.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.18 no.1
• /
• pp.11-19
• /
• 2008

Mean levels of airborne bacteria, airborne fungi, temperature, relative humidity and carbon dioxide in total 69 general offices were $426({\pm}83)\;cfu/m^3$, $234({\pm}125)\;cfu/m^3$, $25.9({\pm}1.3)\;^{\circ}C$, $57.7({\pm}8.6)\;%$, $422({\pm}38)\;ppm$, respectively. The I/O ratio of airborne bacteria and fungi was over 1 and there was no significant difference among temperature, relative humidity and carbon dioxide in total 69 general offices. In construction period, a concentration of airborne bacteria and fungi was significantly highest in general offices constructed under one year and over three years since construction, respectively (p<0.05). The concentration of airborne fungi in general offices located at basement was significantly higher than those located at ground (p<0.05). No significant difference of airborne bacteria and fungi in general offices was found regardless of installation of HVAC system (p>0.05). The dominant bacterial genera identified in general offices was Staphylococcus, followed by Micrococcus, Bacillus, and Corynebacterium while usarium, Penicillium, Aspergillus, Alternaria, Rhizopus and Mucor were identified as dominant fungal genera in general offices.

• Mycobiology
• /
• v.47 no.3
• /
• pp.335-339
• /
• 2019

Endophytic fungi have the ability to live inside the host plant tissues without causing neither symptoms of diseases/or harm. Opportunistic infections are accountable for majority of the outbreaks, thereby putting a burden on the health system. To investigate and characterize the bioactive compounds for the control of bacteria of clinical importance, extracts from endophytic fungi were isolated from indigenous South African medicinal plants. Extracts from endophytic fungi were isolated from 133 fungal strains and screened against Gram positive and negative bacteria namely Bacillus cereus, Escherichia coli, Enterococcus faecium, and E. gallinarum using disk diffusion. Furthermore, gas chromatography-mass spectrometry was performed to identify the bioactive compounds. Sixteen out of one hundred and thirty-three (12%) fungi extracts exhibited antibacterial properties against some of the selected bacteria. E. coli was found to be the most susceptible in contrast to E. faecium and E. gallinarum which were the most resistant. The isolate MHE 68, identified as Alternaria sp. displayed the greater spectrum of antibacterial activities by controlling selected clinical bacteria strains including resistant E. faecium and E. gallinarum. The chemical analysis of the extract from MHE 68 indicated that linoleic acid (9,12-octadecadienoic acid (Z,Z)) and cyclodecasiloxane could be accountable for the antibacterial activity. This is the first study conducted on the secondary metabolites produced by endophytic fungal strains isolated from the Pelargonium sidoides DC. possessing antibacterial properties.

• Mycobiology
• /
• v.28 no.4
• /
• pp.190-192
• /
• 2000

Antifungal bacteria for biological control of plant diseases or production of novel antibiotics to plant pathogens were isolated in 1997 from various soils of Ansung, Chunan, Koyang, and Paju in Korea. Sixty-four bacterial strains pre-screened from approximately 1,400 strains were tested on V-8 juice agar against eight plant pathogenic fungi using in vitro bioassay technique for inhibition of mycelial growth. Test pathogens were Alternaria mali, Colletotrichum gloeosporioides, C. orbiculare, Fusarium oxysporum f. sp. cucumerinum, F. oxysporum f. sp. lycopersici, Magnaporthe grisea, Phytophthora capsici, and Rhizoctonia solani. A wide range of antifungal activity of bacterial strains was found against the pathogenic fungi, and strain RC-B77 showed the best antifungal activity. Correlation analysis between inhibition of each fungus and mean inhibition of all eight fungi by 64 bacterial strains revealed that C. gloeosporioides would be best appropriate for detecting bacterial strains producing antibiotics with potential as biocontrol agents for plant pathogens.