• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.767-772
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• 2008

Biodegradation of endocrine-disrupting phthalates [diethyl phthalate (DEP), dimethyl phthalate (DMP), butylbenzyl phthalate (BBP)] was investigated with 10 white rot fungi isolated in Korea. When the fungal mycelia were added together with 100 mg/l of phthalate into yeast extract-malt extract-glucose (YMG) medium, Pleurotus ostreatus, Irpex lacteus, Polyporus brumalis, Merulius tremellosus, Trametes versicolor, and T. versicolor MrP1 and MrP13 (transformant of the Mn-repressed peroxidase gene of T. versicolor) could remove almost all of the 3 kinds of phthalates within 12 days of incubation. When the phthalates were added to 5-day pregrown fungal cultures, most fungi except I. lacteus showed the increased removal of the phthalates compared with those of the non-pregrown cultures. In both culture conditions, p. ostreatus showed the highest degradation rates for the 3 phthalates tested. BBP was degraded with the highest rates among the 3 phthalates by all fungal strains. Only 14.9% of 100 mg/I BBP was degraded by the supernatant of P. ostreatus culture in YMG medium in 4 days of incubation, but the washed or homogenized mycelium of P. ostreatus could remove 100% of BBP within 2 days even in distilled water, indicating that the initial BBP biodegradation by P. ostreatus may be attributed to mycelium-associated enzymes rather than extracellular enzymes. The biodegradation rate of BBP by the immobilized cells of P. ostreatus was almost same as that in the suspended culture. The estrogenic activity of 100 mg/I DMP decreased during biodegradation by P. ostreatus.

• 한국환경과학회지
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• 제14권9호
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• pp.827-835
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• 2005

A three-dimensional ecological model (EMT -3D) was applied to Nonylphenol in Tokyo Bay. EMT -3D was calibrated with data obtained in the study area. The simulated results of dissolved Nonylphenol were in good agreement with the observed values, with a correlation coefficient(R) of 0.7707 and a coefficient of determination (R2) of 0.5940. The results of sensitivity analysis showed that biodegradation rate and bioconcentration factor are most important factors for dissolved Nonylphenol and Nonylphenol in phytoplankton, respectively. In the case of Nonylphenol in particulate organic carbon, biodegradation rate and partition coefficient were important factors. Therefore, the parameters must be carefully considered in the modeling. The mass balance results showed that standing stocks of Nonylphenol in water, in particulate organic carbon and in phytoplankton are $8.60\times 10^5\;g,\;2.19\times 10^2\;g\;and\;3.78\times 10^0\;g$ respectively. With respect to the flux of dissolved Nonylphenol, biodegradation in the water column, effluent to the open sea and partition to particulate organic carbon were $6.02\times10^3\;g/day,\;6.02\times10^2\;g/day\;and\;1.02\times10^1\;g/day$, respectively.

• 한국환경과학회지
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• 제31권3호
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• pp.227-235
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• 2022

In this study, a biodegradation model of based on molecular cellulose was established. It is a mathematical, kinetic model, assuming that two major enzymes randomly break glycosidic bonds of cellulose molecules, and calculates the number of molecules by applying the corresponding probability and degradation reaction coefficients. Model calculations considered enzyme dose, cellulose chain length, and reaction rate constant ratio. Degradation increased almost by two folds with increase of temperature (5℃→25℃). The change of degradation was not significant over the higher temperatures. As temperature increased, the degradation rate of the molecules increased along with higher production of shorter chain molecules. As the reaction rates of the two enzymes were comparative the degree of degradation for any combinations of enzyme application was not affected much. Enzyme dose was also tested through experiment. While enzyme dose ranged from 1 mg/L to 10 mg/L, the gap between real data and model calculations was trivial. However, at higher dose of those enzymes (>15 mg/L), the experimental result showed the lower concentrations of reductive sugar than the corresponding model calculation did. We determined that the optimal enzyme dose for maximum generation of reductive sugar was 10 mg/L.

• 미생물학회지
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• 제36권2호
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• pp.84-90
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• 2000

Psudomonas sp. RY-1이 생성하는 extracellular depolymerase system을 이용하여 단위체의 결가지에 서로 다른 탄소 길이와 불포와기를 함유하는 medium-chain-length polyhdroxyalkanoates (MCL-PHAs)의 생분해도를 시럼실 조건에서 조사하였다. 생분애도는 평파내지에서의 clear zone 형성, 효소 처리에 의한 고분자 현탁액의 탁도 감소 및 호흡량의 경시적 변화로 측정하였다. Pseudomonas sp. RY-1은 MCL-PHA depolymerase의 생성을 통하여 조사된 모든 종류의 MCl-PHAs를 분해할 수 있었으나, 이 효소의 생성은 쉽게 이용될수 있는 이차기질에 의해 저해받는 것으로 나타났다. MCl-PHAs의 분해율이 단위체의 탄소수가 홀수개로 구성된 고분자에 비하여 보다 높았다. 곁가지에 분포화기를 함유한 MCl-PHAs는 불포화기를 갖지 아니하는 고분자에 비하여 분해가 빠르게 이루어졌으며, 이들의 분해는 고분자의 결정화도와 밀접한 관련이 있는 것으로 나타났다.

• 한국산학기술학회논문지
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• 제7권4호
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• pp.704-708
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• 2006

경유로 오염된 인공오염토양을 효과적으로 정화하기위하여 물리 화학적 처리방법인 펜톤 산화반응과 생물학적 처리방법인 근권미생물의 활성도를 이용하는 방법을 연속적으로 적용하였다. 펜톤산화반응에서는 과산화수소의 농도가 증가할수록 TPH의 제거율이 증가하였으며 근권미생물 반응실험에서의 TPH 제거 효율은 콩(83.5%)<벼(81.5%)<대조군(76%) 순으로 나타났다.

• Journal of the Korean Wood Science and Technology
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• 제38권6호
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• pp.568-578
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• 2010

본 연구에서는 다양한 목재부후균의 polychlorinated biphenyls (PCBs) 생분해 가능성을 구명하고자 7종의 백색부후균을 이용하여 PCB 혼합물 중 가장 분해가 어렵다고 알려진 Aroclor 1254와 1260을 대상으로 분해력이 우수한 목재부후균을 선발하였다. 그리고 선발된 목재부후균을 이용하여 GC 분석을 통해 Aroclor 1254, 1260의 분해율을 조사하였다. 고체배지 저항성 테스트를 통해 우수분해 균주로 선발된 Cystidodontia isubellina 는 다른 균주에 비해 균사생장량의 억제가 가장 적었으며 상대적으로 생장속도도 빠른 특징을 나타냈다. 선발된 C. isubellina에 의한 Aroclor 1254와 1260의 분해율 분석 결과, Aroclor 1254배양 13일째 57.57%로 가장 높은 분해율을 나타냈다. Aroclor 1260 역시 배양일수가 증가함에 따라 분해율 역시 증가하는 경향을 보였으며, 배양 13일째 49.43%로, 두 혼합물 모두 기존의 다른 연구에서보다 높은 분해율을 나타냈다.

• KSBB Journal
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• 제26권1호
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• pp.1-6
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• 2011

Contamination of soils, groundwater, air and marine environment with hazardous and toxic chemicals is major side effect by the industrialization. Bioremediation, the application of microorganism or microbial processes to degrade environmental contaminant, is one of the new environmental technologies. Because of low water solubility and volatility of diesel, bioremediation is more efficient than physical and chemical methods. The purpose of this study is biodegradation of diesel in sand by using Rhodococcus fascians, a microorganism isolated from petroleum contaminated soil. This study was performed in the column containing sand obtained from sea sides. Changes in biodegradability of diesel with various flow rates, inoculum sizes, diesel concentrations, and pH were investigated in sand column. The optimal condition for biodegradation of diesel by R. fascians in sand column system was initial pH 8 and air flow rate of 30 mL/min. Higher diesel degradation was achieved at larger inoculum size and the diesel degradation by R. fascians was not inhibited by diesel concentration up to 5%.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.363-367
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• 2003

Batch experiments were performed to determine optimum conditions for biopile. The batch experiments results showed that 12.5 to 17.9% of moisture content was effective to biodegradation of petroleum hydrocarbon regardless of soil texture. Total heterotrophic bacteria populations in the inoculum-treated soil were greater than of the control and nutrient-amended soil in the early stage, but the populations in the inoculum and nutrient-amended soil were not different significantly from those in the latter stage regardless of soil texture. The same trend was observed for petroleum hydrocarbon degrading bacteria populations. The results of the biodegradation capacity experiments showed that there was a decline in the TPH concentrations during the experiments and no significant difference on the biodegradation was observed by treatment in silt soil. Changes of n-C17/pristane and n-C18/phytane ratios in all treated soil were significantly more than those of control. This is a strong indication of biodegradation. The TPH removal rate was calculated at 60% in all treated soil.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권3호
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• pp.88-94
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• 2016

The simultaneous biodegradation between MTBE (Gasoline additives) and BTEX (Benzene, Toluene, Ethyl-benzene, o-Xylene, m-Xylene, p-Xylene) was achieved within a competitive inter-relationship, with not only electron accepters such as nitrate, sulfate, and iron(III) without oxygen, but also with electron donors such as MTBE and BTEX. Preexisting indigenous microorganisms from a domestic sample of gasoline contaminated soil was used for a lab-scale batch test. The result of the test showed that the biodegradation rate of MTBE decreased when there was co-existing MTBE and BTEX, compared to having just MTBE present. The growth of indigenous microorganisms was not affected in the case of the MTBE treatment, whereas the growth of the microorganisms was decreased in combined MTBE and BTEX sample. This may indicate that an inhibitor related to biodegradation when BTEX and MTBE are mixed will be found. This inhibitor may be found to retard the anaerobic conditions needed for efficient breakdown of these complex carbon chain molecules in-situ. Moreover, it is also possible that an unknown competitive reaction is being imposed on the interactions between MTBE and BTEX dependent on conditions, ratios of mixture, etc.

• 상하수도학회지
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• 제18권6호
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• pp.724-730
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• 2004

Effects of the biosurfactant produced by Rhodococcus erythropolis on the solubilization and biodegradation of phenanthrene were investigated. Based on surface tension measurements, the average critical micelle concentration of the biosurfactant was estimated to be about 16mg TOC/L. The apparent solubility of phenanthrene increased linearly with the addition of biosurfactants above the CMC, and the concentration of solubilized phenanthrene was 38.9mg/L in 322mg TOC/L biosurfactant solution. The weight-solubilization ratio of biosurfactants for phenanthrene was approximately 118.8mg/g, this value was over 5 times greater than that of sodium dodecyl sulfate. Using a known phenanthrene degrader, batch phenanthrene biodegradation experiments were conducted with and without biosurfactants in liquid culture. The rate and extent of phenanthrene mineralization by the phenanthrene degrader with biosurfactants were much greater than those without biosurfactants. The greater phenanthrene mineralization observed in the presence of biosurfactants is attributed to the increased phenanthrene concentration in the aqueous culture due to the partitioning of the compound to biosurfactant micelles. The biosurfactant did not exhibit any toxic effect on mineralization of glucose by the phenanthrene-degrader.