• 한국환경과학회지
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• 제29권11호
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• pp.1109-1123
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• 2020

In this study, the amount of harmful fungi and bacteria contained in the drainage and culture medium from the paprika hydroponic facility is identified. In addition, by proposing the necessity of effective purification of discharged drainage, this study attempted to confirm the possibility of drainage reuse. Finally, this study provides basic data on the basis for calculating the need for purification facilities in the future, as well as improvements in horticulture facility for sustainable agriculture. As a result of the analysis, a total of 12 types of fungi were detected in paprika medium and 10 types of fungi were detected in the drainage, and their densities were 130 and 68, respectively. Among the fungi detected in the media and drainage of the paprika hydroponic facility, the fungi with the highest detection frequency are Fusarium, Phytophthora, and Pythium. In the case of bacteria, a total of 2 types of bacteria were detected in the paprika facilities, and the density was 28 and 23, respectively. Therefore, in order to reuse the drainage and settle the circulating hydroponic cultivation system, a water treatment process capable of appropriate treatment is required.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.323-331
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• 2003

Bacteria and fungi are fundamental biotic components of natural biogeochemical cycles for metals and metalloids, and play important roles in dissolution, precipitation, oxidation and reduction processes. Some processes catalyzed by microorganisms also have important applications in environmental biotechnology in the areas of ore leaching and bioremediation.

• 한국환경농학회지
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• 제14권3호
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• pp.345-350
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• 1995

주택용 소형 퇴비화용기(type 3과 type 4)를 제작하였다. 두 가지 용기의 구조는 다같이 용기의 벽을 이중으로 하였으며 type 4는 보온을 하였고 type 3은 보온을 하지 않았다. 실험실 실험을 통하여 퇴비화하는 과정에서 다음과 같은 미생물의 변동상이 조사되었다 1. 겨울철에는 중온성 세균이 감소하면, 고온성 세균이 증가하였으나 봄철과 여름철에는 퇴비화 초기 중온성 세균과 고온성 세균이 동시에 증가와 감소를 하는 경향이 있었다. 2. 겨울철에는 중온성 방선균과 고온성 방선균이 퇴비화 1주째 함께 감소하였다. 봄철에는 고온성 방선균은 급격하게 증가하였으나 여름철에는 고온성 방선균이 완만한 증가를 보였다. 3. 사상균에서도 겨울 1주 째 까지를 제외하고는 퇴비화 초기에 중온성 사상균과 고온성 사상균이 동시에 증가와 감소를 하였다. 4. 중온성 세균, 방선균, 사상균은 균수에서 차이가 없었으나 봄철에만 사상균의 균수가 적었다. 5. 퇴비화 말기 중온성 균류가 겨울철, 여름철에는 감소하였으나 봄철에는 증가하였다.

• 한국초지조사료학회지
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• 제18권2호
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• pp.133-142
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• 1998

This study was conducted to investigate the effects of antagonistic bacteria and pathogenic fungi on the growth of tall fescue(Festuca arundinacea Schreb.) in continuous cropping soil(CCS) and non-continuous cropping soil(NCCS). Tall fescue was established by seeding into pots of 11 cm in diameter and 9 cm in depth containing 1 : 1 mixture of soil and vermiculite, and cultivated at pots with antagonistic bacteria and pathogenic fungi in a vinyl house. The bacteria used in this study were Bacillus subtilis and hsants. B. subtilis was isolated and identified kern forage rhizosphere soil and fusants were isolated through cell hsion from B. subtilis and B. thwingiensis. B. subtilis was named as B. subtilis 101 and hsants were named as F-3, F-7 and F-8. In dark culture experiment, tall fescue inoculated with the antagonistic bacteria lived longer than that of control in both CCS and NCCS. However, tall fescue of CCS lived shorter than that of NCCS. Dry weight of tall fescue inoculated with the antagonistic bacteria was higher than that of tall fescue inoculated with pathogenic hngi in both CCS and NCCS(P< 0.05), and the antagonistic bacteria showed positive effects on the growth of tall fescue. However, Dry weight of tall fescue was decreased by the inoculation of the pathogenic b g i in both CCS and NCCS(P< 0.05).

• 대한한의학방제학회지
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• 제19권2호
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• pp.83-92
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• 2011

Objectives : This study was carried out to moniter microbial flora on freeze-dried herbal powder and identify isolated bacteria. Methods : We measured the total number of bacteria and fungi in 29 herbal powder which had made according to the guideline of KFDA. For the identification, we observed microscopic properties and carried out polymerase chain reaction(PCR). The purified DNA was analyzed by DNA sequencer. Results : Among the 29 herbal powders, the fungi were detected only one sample as unacceptable range of total aerobic bacteria. Isolated bacteria were identified as Bacillus cereus, B. subtilis, B. megaterium, B. licheniformis, Erwinia tasmaniensis, E. amylovora, and Pantoea agglomerans by 16S rDNA analysis. E. tasmaniensis was observed 20 herbal samples. Conclusions : According to above results, further studies for the effective sterilization of low herbal materials should be needed.

• 한국토양비료학회지
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• 제31권3호
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• pp.291-300
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• 1998

본 시험은 염류의 종류와 처리함량에 따른 작물근권 생태계의 미생물상 변동과 근권정착성을 구명하고자 하였다. 토양처리 염류($KNO_3$, $K_2HPO_4$, KCl, $K_2SO_4$)의 염농도(EC)와 포자형성세균, 그람음성세균수는 부의 상관관계를 보였으며, $K_2HPO_4$, $K_2SO_4$보다 KCl, $KNO_3$ 처리구에서 균수가 급격히 감소하였다. 균형염 처리토양의 미생물 밀도는 탄소원 첨가의 경우 그람음성세균은 EC $0.5dS\;m^{-1}$, 포자형성균은 EC $2.1dS\;m^{-1}$, 사상균 및 Fusarium sp.은 EC $8.0dS\;m^{-1}$에서 최대의 균수를 보였다. 균형염 처리토양의 Bacteria/Fungi 율은 염농도가 높아질수록 현저히 감소하며 토양처리 10일 경과후 757~1571, 30일 경과 후 89~215로 현저하게 낮아졌다. 오이, 토마토 근권 미생물의 뿌리정착밀도는 토양의 염농도가 높아질수록 형광성 Pseudomonas sp.은 현저하게 감소하였으나 병원성 Fusarium sp.은 증가하였다.

• Journal of Ecology and Environment
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• 제36권4호
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• pp.223-233
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• 2013

Acid deposition is one of the most serious environmental problems in ecosystems. The present study surveyed the effects of simulated acid rain on leaf litter mass loss and microbial community in the decomposing leaf litter of Sorbus anifolia in a microcosm at $23^{\circ}C$ and 40% humidity. Microbial biomass was measured by substrate-induced respiration (SIR) and phospholipid fatty acids (PLFAs), and the microbial community structures were determined by composition of PLFAs at each interval of decomposition in litter sample and at each pH treatment. The microbial biomass showed peaks at mid-stage of decomposition, decreasing at the late stage. The leaf litter mass loss of S. anifolia decreased with decreasing pH during early and mid-decomposition stages; however the mass loss becomes similar between pH treatments at late-decomposition stage. The acidification remarkably lowers the microbial biomass of bacteria and fungi; however, microbial diversity was unchanged between pH treatments at each stage of litter decomposition. With changes of decomposition stage and pH treatment there were considerable differences in replacement and compensation of microbial species. Fungi/bacteria ratio was considerably changed by pH treatment. The PLFA profile showed significantly larger fungi/bacteria ratio at pH 5 than pH 3 at the early stage of decomposition, and the difference becomes smaller at the later decomposition stage. At low pH, pH 3 and pH 4, the fungi/bacteria ratios were stable according to the litter decomposition stages. Simulated acid rain caused decreases of 10Me17:0, 16:1${\omega}$7c, 18:1${\omega}$7, 15:0, but increase of 24:0. In addition, litter mass loss showed significant positive correlation with microbial biomass measured by SIR and PLFA on the decomposing leaf litter.

• 한국토양비료학회지
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• 제47권6호
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• pp.496-499
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• 2014

The present study investigated variations in soil microbial communities and the chemical properties of forest soils by differing amounts of penetrating sunlight. The soil temperature was significantly higher in higher light-penetrated soils. Higher light-penetrated soils (LP70) showed significantly more fungal communities than the lower light-penetrated soils (LP40 and LP50) (p < 0.05). The $NH_4$-N concentration in LP70 was significantly lower than those of LP40 and LP50, whereas the other chemical properties showed no significant difference among the soils. The cy19:0 to $18:1{\omega}7c$ ratio was significantly lower in LP70 than in LP 40 and LP50 showing the negative correlation of light level with microbial stresses (p < 0.05). The soil microbial communities and the chemical properties that showed positive eigenvector coefficients for PC1 were the fungi to bacteria, fungi, arbuscular mycorrhizal fungi, and Gram-positive bacteria, whereas negative eigenvector coefficients were found for $NH_4$-N, actinomycetes, Gram-negative bacteria, and bacteria. Consequently, the amount of penetrating light was responsible for microbial compositions in the forest soils in correlation with the concentration of $NH_4$-N and soil temperature.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1269-1278
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• 2013

Crack remediation on the surface of cement mortar using microbiological calcium carbonate ($CaCO_3$) precipitation (MICP) has been investigated as a microbial sealing agent on construction materials. However, MICP research has never acknowledged the antifungal properties of calcite-forming bacteria (CFB). Since fungal colonization on concrete surfaces can trigger biodeterioration processes, fungi on concrete buildings have to be prevented. Therefore, to develop a microbial sealing agent that has antifungal properties to remediate cement cracks without deteriorative fungal colonization, we introduced an antifungal CFB isolated from oceanic islands (Dokdo islands, territory of South Korea, located at the edge of the East Sea in Korea.). The isolation of CFB was done using B4 or urea-$CaCl_2$ media. Furthermore, antifungal assays were done using the pairing culture and disk diffusion methods. Five isolated CFB showed $CaCO_3$ precipitation and antifungal activities against deteriorative fungal strains. Subsequently, five candidate bacteria were identified using 16S rDNA sequence analysis. Crack remediation, fungi growth inhibition, and water permeability reduction of antifungal CFB-treated cement surfaces were tested. All antifungal CFB showed crack remediation abilities, but only three strains (KNUC2100, 2103, and 2106) reduced the water permeability. Furthermore, these three strains showed fungi growth inhibition. This paper is the first application research of CFB that have antifungal activity, for an eco-friendly improvement of construction materials.

• Journal of Korean Society for Atmospheric Environment
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• 제23권E1호
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• pp.1-9
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• 2007

In Korea, there is only a limited amount of information currently available on the levels of airborne bacteria and fungi of cattle sheds, although certain portions of people are potentially exposed to these bioaerosols in cattle sheds. Accordingly, the current study measured them inside cattle sheds, inside and outside farmers' houses near the sheds, and/or inside residential houses far away from the sheds during winter, 2004 and summer, 2005. The airborne bacteria and fungi were detected in most samples in the cattle farmers' houses as well as in the cattle sheds. Aspergillus, Cladosporium, and Penicillium, which have been associated with adverse health effects, were three most prevalent fungal genera, and they took most of the total fungi (more than 69%). The microbial concentrations measured inside the cattle sheds were comparable to those in other reports. Nevertheless, the present arithmetic and geometric mean (GM) microbial concentrations exceeded the Korean guideline for total airborne bacteria at medical facilities ($800\;CFU\;m^{-3}$), the current GM residential indoor concentrations at houses, and the residential indoor levels reported in other countries. The present findings suggest the need for a strategy to reduce Korean cattle farmers' exposure to these microorganisms. In contrast to the microbes, it is suggested that the cattle shed is not an important microenvironment for $PM_{10}$ exposure. Two characteristics examined in this study (seasonal variation and summer survey period, i.e., temperature and humidity) were all important for the cattle farmers' occupational exposure to airborne microbes. The lack of constancy between highest and lowest concentrations of bioaerosols over the survey period further suggests the necessity of performing a long-term survey to better examine farmer exposure levels and their variability.