• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.179-182
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• 2000

Toluene-degrading bacterium, Microbacterium esteraromaticum CS3-1 was isolated from the biofilter for the removal of BTEX. Microbacterium esteraromaticum CS3-1 was shown to utilize toluene as a primary carbon and energy source. Effect of mixed BTEX gases on toluene degradation rate by M. esteraromaticum CS3-1 was investigated in this study. Toluene degradation rate was 2.26(only toluene), 2.06(toluene+benzene), 2.57(toluene+ethylbenzene), and 4.74(toluene+xylene) mmole $toluene\;{\cdot}\;g-DCW^{-1}\;{\cdot}\;h^{-1}$. Toluene degradation rate was 2.26(only toluene), 1.23(toluene+benzene+ethylbenzene), 1.52 (toluene+ethylbenzene+xylene), and 1.76(toluene+benzene+ethylbenzene+xylene) mmole $toluene\;{\cdot}\;g-DCW^{-1}\;{\cdot}\;h^{-1}$. The presence of BTEX compounds over three mixtures had a negative effect on toluene degradation rate. Toluene degradation rates were enhanced by the presence of ethylbenzene or xylene, whereas the presence of benzene had a negative effect on toluene degradation rate in comparison with toluene degradation rate when only toluene is existent.

• KSBB Journal
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• 제13권5호
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• pp.561-568
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• 1998

Two cometabolic trichloroethylene (TC) degraders, Pseudomonas putida F1 and Burkholderia (Pseudomonas) cepacia G4, were found to catabolize phenol, benzene, toluene, and ethylbenzene as carbon and energy sources. Resting cells of P. putida F1 and B. cepacia G4 grown in the presence of toluene and phenol, respectively, were able to degrade not only benzene, toluene and ethylenzene but also TCE and p-xylene. However, these two strains grown in the absence of toluene or phenol did not degrade TCE and p-xylene. Therefore, it was tentatively concluded that cometabolic degradation of TC and p-xylene was mediated by toluene dioxygenase (P. putida F1) or toluene-2-monooxygenase (B. cepacia G4). Maximal degradation rates of BTEX and TCE by toluene- and phenol-induced resting cells of P. putida F1 and B. cepacia G4 were appeared to be 4-530 nmol/(min$.$mg cell protein) when a single compound was solely served as a target substrate. In case of double substrates, the benzene degradation rate by P. putida F1 in the presence of toluene was decreased up to one seventh of that for the single substrate. TCE degradation rate was also linearly decreased as toluene concentration increased. On the other hand, toluene degradation rate was enhanced by benzene and TCE. For B. cepacia G4, degradation rates of TCE and toluene increased 4 times in the presence of 50 ${\mu}$M phenol. From these results, it was concluded that a degradation rate of a compound in the presence of another cosubstrate(s) could not be predicted by simply generalizing antagonistic or synergistic interactions between substrates.

• 한국환경과학회지
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• 제7권3호
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• pp.393-400
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• 1998

A microorganism, Klebsiella gr. 47, capable of degrading BTX(benzene, toluene and xylene) was isolated from oil-contaminated soil and its characteristics of BTX degradation were investigated. When benzene and toluene were fed to Klebstella gr. 47 simulataneously, they showed competitive ingibition. The degradation rate of xylene was enhanced as much as 3 times when xylene was fed with benzene or toluene. Degradation rate of benzene and toluene was also enhanced by cocultured with Alcaligenes xylosoxidans. When benzene-adapted microorganism was used, each BTX compound was degraded efficiently within 5 hours.

• 환경위생공학
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• 제14권1호
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• pp.24-30
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• 1999

A biological filter for treatment of toluene among volatile organic compounds was studied. The investigation was conducted using specially built stainless steel columns packed with granular activated carbon and cold for removal of toluene. The G.A. and mold as filter material was also coated with Pseudomonas putida microorganisms.The biofilter unit was operated in the condition of moisture content vairation at gas loading rate of 12.5 l/min. Gaseous toluene taken from tedlar bag was analyzed by the use of G.C equipped with F.I.d detector. The removal efficiency of gaseous toluene was 95% at average inlet concentration of 950 ppm during bio-degradation operating condition. Effective removal efficiency was obtained with moisture content 27.5% at activated carbon and 32% at mold in this study. The effective operating condition were obtained with pH 6-8, temperature 28-42℃ for microbial degradation at gas loading rate of 12.5 l/min in packed material.

• 대한환경공학회지
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• 제22권2호
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• pp.375-383
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• 2000

유일로 오염된 지역의 토양에서 toluene을 탄소원으로 이용하는 혼합미생물을 분리하여 toluene, benzene, ethylbenzene 및 xylene isomers(BTEX)의 분해특성을 관찰하였다. 단일기질 실험에서는 모든 BTEX의 분해가 이루어졌으며 toluene, benzene, ethylbenzene, p-xylene 순서로 분해되었다. BTEX 혼합기질 분해실험에서는 단일기질일 때보다 분해속도가 상대적으로 느려졌으며, ethylbenzene이 benzene보다 먼저 분해되는 것이 관찰되었다. 이중 혼합물질 반응 실험에서는 방해작용(inhibition), 촉진작용(stimulation), 그리고 비반응(non-interaction)과 같은 다양한 기질반응이 관찰되었으며, ethylbenzene은 benzene, toluene, xylene의 분해에 강한 방해영향을 주었다. Xylene 분해특성에서 m- 및 p-xylene은 혼합미생물에 탄소원으로 이용되었으며 benzene이나 toluene이 동시에 존재할 때는 xylene isomer의 분해가 촉진되었다. 그러나 o-xylene의 분해는 benzene에 의해서만 촉진되었다.

• 미생물학회지
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• 제34권3호
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• pp.96-100
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• 1998

연안 저서시료에 의한 benzene과 toluene, meta-xylene(BTX)의 혐기성 분해를 촉진시키기 위해 전자수용체 및 접종 시료의 적응에 따른 분해 정도를 조사하였다. 비적응 시료에 의해 BTX 는 10주 정도의 적응기 후에 분해되기 시작하여 16주 경과 후 benzene은 37~61%, toluene은 57~61% 분해되었다. 접종 시료별 혐기성 분해도는 유해물질의 유입이 많은 지역에서 채취한 시료가 우수한 분해력을 보였다. 그러나 6개월 가량 적응시킨 결과, 접종 시료별 BTX의 분해 차이는 나타나지 않았으며 적응기가 발생하지 않은 채 빨리 분해시켰다. BTX 단일 화합물을 첨가하였을 경우, 메탄생성 조건에서도 분해도가 다른 조건에 비해 다소 느리게 일어났으며, BTX 혼합체에서는 탈질화 조건에서 분해력이 다소 떨어졌다. BTX의 성분별 분해 정도는 m-xylene이 가장 빨랐으며, benzene의 분해가 가장 느렸다. 오랜 기간 BTX에 적응된 시료에 의해서도 m-xylene의 분해가 빨랐으나 benzene의 분해도 신속히 일어나 toluene과 비슷한 분해율을 나타냈다. 이러한 BTX의 혐기성 분해에 따라 독성이 감소하였다.

• 산업기술연구
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• 제22권B호
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• pp.117-124
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• 2002

We prepared the nano-sized $TiO_2$ particles by the diffusion flame reactor and investigated the effects of several process variables on the generation and transport properties of $TiO_2$ particle. As the length from the tip of diffusion flame reactor increases, the size of $TiO_2$ particle increases by the coagulation between particles. The structure of $TiO_2$ particles prepared is almost found to be anatase. It was found that the $TiO_2$ particle size depends more largely on the change of reactor temperature than on the change of inlet $TiCl_4$ concentration. By the photo-degradation experiment of phenol and toluene with the prepared $TiO_2$ particles, we found that the photo-degradation efficiencies of phenol and toluene change, depending on the process variables such as size of $TiO_2$ photocatlysts, concentration of phenol or toluene. Degradation efficiencies of phenol and toluene was above 90% in our experiments in 60 minutes.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.34-39
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• 2005

Trichloroethylene (TCE) is an environmental contaminant provoking genetic mutation and damages to liver and central nerve system even at low concentrations. A practical scheme is reported using toluene as a primary substrate to revitalize the biofilter column for an extended period of TCE degradation. The rate of trichloroethylene (TCE) degradation by Pseudomonas putida F1 at $25^{\circ}C$ decreased exponentially with time, without toluene feeding to a biofilter column ($11\;cm\;I.D.{\times}95\;cm$ height). The rate of decrease was 2.5 times faster at a TCE concentration of $970\;{\mu}g/L$ compared to a TCE concentration of $110\;{\mu}g/L$. The TCE itself was not toxic to the cells, but the metabolic intermediates of the TCE degradation were apparently responsible for the decrease in the TCE degradation rate. A short-term (2 h) supply of toluene ($2,200\;{\mu}g/L$) at an empty bed residence time (EBRT) of 6.4 min recovered the relative column activity by $43\%$ when the TCE removal efficiency at the time of toluene feeding was $58\%$. The recovery of the TCE removal efficiency increased at higher incoming toluene concentrations and longer toluene supply durations according to the Monod type of kinetic expressions. A longer duration ($1.4{\sim}2.4$ times) of toluene supply increased the recovery of the TCE removal efficiency by $20\%$ for the same toluene load.

• 생명과학회지
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• 제9권6호
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• pp.715-721
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• 1999

분리된 toluene내성세균 Pseudomonas sp. BCNU 154을 생물분해반응에 적용하고저 그 가능성을 조사하였다. 방향 족화합물 16개을 대상으로 저화능을 조사한 결과 cumene, cyclohexane, ethylbenzene, p-xylen, m-xylen, toluene 그리고 diphenylether가 공시균쥬에 의해 자화됨이 확인 되었다. Pseudomonas sp. BCNU 154는 toluene, ethylbenzene 그리고 p-xylen 그리고 cumene을 호기적으로 분해하였다. Touene은 12시간후에 완전히 분해되었고, p-xylene과 cumene은 12시간배양시 90% 분해되었으며, ethylbenzene은 12시간 배양시 75%가 분해되었다.

• 유기물자원화
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• 제14권3호
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• pp.117-125
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• 2006

원유에 오염된 토양으로부터 톨루엔을 분해할 수 있는 미생물을 분리하였으며 동정결과 Pseudomonas fluorescence였다. 이 미생물을 생물학적 톨루엔 처리공정에 사용하기 위해 온도, 톨루엔 농도, pH, 질소원 등의 환경영향이 분해에 미치는 영향에 대해서 연구를 하였다. 이 미생물의 최적 분해 온도는 $30^{\circ}C$였으며 이 때 최대 비성장속도와 최대 비소모속도는 각각 $0.76hr^{-1}$와 $0.36hr^{-1}$이었다. $10^{\circ}C$ 와 $40^{\circ}C$에서는 톨루엔을 분해하지 못하였으나 $30^{\circ}C$에 적응한 미생물은 $10^{\circ}C$에서 17시간 만에 100mg/L의 톨루엔을 완전히 분해하였고 $40^{\circ}C$ 에서는 30시간 동안 80% 정도 분해할 수 있었다. 본 미생물은 200mg/L 이상의 톨루엔은 분해할 수 없었으나 20mg/L의 낮은 농도의 톨루엔에 적응을 시킴으로써 300mg/L의 톨루엔까지 분해할 수 있었다. pH는 5.5~9.0 범위에서 분해 속도에 별다른 영향을 미치지 않는 것으로 나타났다. 암모늄 (${NH_4}^+$) 대신 질산염(${NO_3}^-$)을 사용했을 때 적응기가 2~10시간 정도 길어졌고 미생물 수율이 45% 정도 감소하였다. 그러나 적응기가 지난 후의 톨루엔 분해속도에서는 별 차이를 보이지 않았다. 본 연구에서 얻은 결과들은 향후 바이오필터 등의 생물학적 톨루엔 처리공정 개발에 유용하게 사용될 것으로 기대된다.