• Mycobiology
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• v.35 no.1
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• pp.36-38
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• 2007

Stored rice was collected from rice processing complexes of National Agricultural Cooperative Federation of 11 regions in Korea to evaluate the occurrence of fungi and bacteria and to identify the predominant fungi and bacteria to the genus levels. Most rice samples generally produced the higher levels of fungi and bacteria than white rice. The occurrence of fungi and bacteria varied in various locations of Korea. Among fungi observed, Aspergillus spp. and Penicillium spp. were dominant in the samples and Aspergillus spp. were observed more frequently than Penicillium spp. Predominant bacteria from rice and white rice samples tentatively belonged to the Genus Bacillus, Pectobacterium, Pantoea, and Microbacterium according to BIOLOG and FAME analyses. The results of this study showed that rice in Korea was contaminated in a relatively high level by two dominant storage fungi such as Aspergillus spp. and Penicillium spp. In addition, occurrence of mycotoxins in rice by the fungi could be possible and thus it is necessary to control the storage fungi.

• Journal of Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.440-448
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• 2004

Airborne bacteria, gram negative bacteria (GNB) and fungi were measured in 70 class of 17 kindergartens. The objective of this study is to identify the factors influencing airborne concentrations of bacteria, GNB and fungi using multiple regression analysis. The average concentrations of bacteria and fungi exceeded $1,000\;CFU/m^3$. The average of GNB was $3.7{\times}10^2\;CFU/m^3$. This results indicated that air of kindergartens was contaminated with microbes such as bacteria and fungi. ANOVA test found that the concentrations of bacteria, GNB and fungi were significantly different by the characteristics of weather (rain, after rain, sunny) sampling date (July, August, September and October), the location of sampling site (ground level and basement) and the location of toilet (inside class, nearby class and away class). Multiple regression tests concluded that sampling date, the scale of city where kindergartens are located, the location of sampling site and ventilation efficiency can significantly affect the airborne concentration of bacteria, GNB and fungi. Most of these factors could be related moisture. Environmental factors that can cause the increment of moisture should be controlled in order to reduce airborne concentration of bacteria, GNB and fungi. Legal actions concerning prohibition on the presence of toilet inside class and ventilation criteria should be taken.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.6
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• pp.797-802
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• 2001

Two strains of rumen fungi (Piromyces rhizinflata B157, Orpinomyces joyonii SG4) and three strains of rumen cellulolytic bacteria (Ruminococcus albus B199, Ruminococcus flavefaciens FD1 and Fibrobacter succinogenes S85) were used as mono-cultures or combinationally arranged as co- and sequential-cultures to assess the relative contributions and interactions between rumen fungi and cellulolytic bacteria on rice straw degradation. The rates of dry matter degradation of co-cultures were similar to those of corresponding bacterial mono-cultures. Compared to corresponding sequential-cultures, the degradation of rice straw was reduced in all co-cultures (P<0.01). Regardless of the microbial species, the cellulolytic bacteria seemed to inhibit the degradation of rice straw by rumen fungi. The high efficiency of fungal cellulolysis seems to affect bacterial degradation rates.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.4
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• pp.274-281
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• 2010

The objectives of this study are (a) to investigate the distribution patterns and exposure concentrations of biological agents in sawmill industries and (b) to compare sampling methods of biological agents. The representative processes of 5 sawmills were selected to measure total airborne bacteria, fungi, endotoxin as well as dust. Airborne bacteria and fungi were measured with one stage impactor, six stage impactor and gelatin filteration methods. Endotoxin was collected with polycarbonate filters and analysed by kinetic chromogenic Limulus Amebocyte Lysate method. Geometric mean levels of airborne bacteria, fungi, endotoxin and dust were 1,864 CFU/$m^3$, 2,252 CFU/$m^3$, 31.5 EU/$m^3$ and 2.4 mg/$m^3$. The ratios of indoor/outdoor concentrations were 3.7 for bacteria, 4.1 for fungi, 3.3 for endotoxin and 9.7 for dust. The respiratory fractions of bacteria were 68.0, 50.9, 49.2 and 45.1% in band-saw, table-saw, rip-saw process and outdoor air. The respiratory fractions of fungi were 78.7, 90.8, 87.5 and 84.8% in band-saw, table-saw, rip-saw process and outdoor air, respectively. There was no significant differences in bacterial concentrations among single stage, six stage impaction and filteration methods. But, fungal concentrations measured with filtration methods were significantly higher than those with impaction methods. Geometric mean levels of airborne bacteria and fungi were higher than the OSHA guideline values of 1,000 CFU/$m^3$. The respiratory fractions of fungi were above 75%. The concentrations of biological agents were significantly different among culture-based sampling methods. In the exposure assessments of biological agents, further studies are needed for the comparisons of diverse sampling methods and the investigations of environmental factors.

• Journal of Environmental Health Sciences
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• v.36 no.3
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• pp.191-198
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• 2010

The aim of this study was to determine the concentrations of air-borne microorganisms (bacteria, fungi, gram negative bacteria (GNB), endotoxins, and respirable suspended particles (RSPs), and their correlation with environmental parameters (temperature, humidity, and carbon dioxide levels) in duck houses. The mean concentrations of bacteria, fungi, and GNB were very high (> $10^6\;CFU/m^3$), and endotoxin levels exceeded $10^3\;EU/m^3$. Among the various work stages, in the task of receiving ducks, bacteria were $6.2{\times}10^6;CFU/m^3$, and GNB were $5.4{\times}10^6\;CFU/m^3$, while RSPs levels were $397.6\;{\mu}g/m^3$ and endotoxin levels were $47.2{\times}10^3\;EU/m^3$ in the task of dividing the ducks, and fungi were $4.9{\times}10^6\;CFU/m^3$ in the task of shipping the ducks. The concentrations of RSPs and endotoxins were significantly higher in tasks involving greater movement of ducks in the house, relative to tasks involving little movement of ducks (p<0.05). Further, with progression in growth of the ducks, the concentrations of bacteria, GNB, endotoxins, and RSPs were significantly increased. There was significant correlation between levels of GNB with bacteria (r=0.75) and fungi (r=0.86), endotoxins with RSPs (r=0.75), bacteria with fungi (r=0.39), and carbon dioxide with RSPs (r=0.38), bacteria (r=0.33), and endotoxins (r=0.31). These results suggest considerable respiratory hazard for farmers in these environments.

• Journal of Environmental Health Sciences
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• v.38 no.4
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• pp.300-310
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• 2012

Objectives: Indoor air quality problems in public spaces have recently become a very important issue in South Korea, because many spend a long time every day indoors. In this study, an extensive literature review was performed on the subject of suspended bacteria and fungi in public facilities. The objective of this study was to evaluate the extent and types of suspended bacteria and fungi in indoor air in South Korea. This study will provide direction to the research in the field of indoor air. Methods: Article reviews was conducted using a search engine and the following keywords; 'bacteria', 'total suspended bacteria', 'fungi' and 'indoor air' from published articles since 2000. Results: Most of the places of measurement were schools, kindergartens, childcare centers and general hospitals. The highest concentrations of total suspended bacteria and fungi were found in schools and kindergartens. Some public facilities exceeded the standard of 800 CFU/$m^3$. There were few studies on other suspended bacteria: Gram Negative Bacteria, Staphylococcus and Klebsiella pneumoniae. Conclusions: It appears that more studies with intensive controls are needed. It was found that schools and kindergartens were most susceptible to microbial indoor air pollution. These results may be able to suggest an indoor standard for suspended bacteria and fungi in South Korea.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.416-424
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• 2014

Objectives: The objective of this study is to analyze the predominant microorganisms in the industry treating MWFs(Metal working fluids). Methods: The bacteria and fungi were collected by agar plate impaction and bulk MWFs in storage tank at 54 sites in 9 shops in South Korea. The dominant bacteria and fungi isolated from agar media were identified by fatty acid analysis and morphological analysis, respectively. Results: Totally 111 dominant bacteria were identified in the process, outdoor, and bulk MWFs. The predominant bacterial genus was Micrococcus and Bacillus in the process and outdoor, Pseudomonas in bulk MWF. Among the identified 119 strains of fungi, Cladosporium and Penicillium genus were dominated. The ratios of bacteria designated biosafety level 2 and 1 were 30% and 21%, respectively. Conclusions: This study has investigated the dominant microorganisms in soluble MWF using industry. And it was useful that the qualitative evaluation method along with quantitative analysis for better understanding of the biological factors in the work environment.

• Safety and Health at Work
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• v.13 no.4
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• pp.487-492
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• 2022

Objective: The exposure levels of disease-causing bacteria and germs were assessed on aircraft cleaning workers on multiple different aircrafts. Method: Five measuring points were selected depending on the aircraft types. Four aircraft cleaning agencies were selected for the test. Aircraft cleaning work was classified as intensive cleaning and general cleaning work. Ventilation in aircraft when sampling during the cleaning operation was categorized into forced ventilation and natural ventilation. The collection of airborne microorganisms was made through inertial impactors which were installed 1.5 meters above the bottom of the aircraft. The airborne bacteria and fungus growth badges were selected by Trytpic Soy Agar and Sabouraud Dextrose Agar. Results: The average concentrations of bacteria in the air were higher in the order of small, medium, and large airplanes. Rainy days had higher concentrations inside and outside the aircraft as compared to those in sunny days. Regarding ventilation, concentrations in natural ventilation were higher than concentrations in forced ventilation. According to the type of work, the concentrations in the intensive cleaning groups (cleaning one plane a day) were lower than those of the ordinary cleaning groups (cleaning several planes per day). Conclusion: The concentration levels of airborne bacteria and fungi in the aircraft surveyed were lower than the indoor environmental standards of Korea (800 cfu/m³ and 500 cfu/m³). The average concentrations of bacteria in the air and fungi in the air were highest in small aircraft owned by Company D.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.489-495
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• 2000

When microorganisms such as bacteria and fungi are injected into porous medium such as soils along with appropriate substrate and nutrients, biomass retained in the soil pore. Soil pore size and shape are varied from the initial condition as a result of biofilm formation, which make hydraulic conductivity reduced. In this research, hydraulic conductivity reduction was measured after microorganism are inoculated and cultured with synthetic substrates and nutrients. Biomass-soil mixture was evaluated its applicability to the field condition as an alternative liner material in landfill by measuring hydraulic conductivity change after repetitive freeze-thaw cycles.

• Journal of Environmental Health Sciences
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• v.33 no.4
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• pp.250-254
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• 2007

The reduction efficiency of air cleaner on particulate contaminants such as dust, airborne bacteria and fungi distributed in the office was relatively higher in case of office with workers than office without workers. This result would be attributed to workers' activities and physical characteristics of particulate contaminants. The air cleaner decreased a concentration of airborne bacteria more than airborne fungi, which implicates that difference of dust adsorption between airborne bacteria and fungi would affect an operation efficiency of air cleaner.