• Journal of Microbiology
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• 제41권3호
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• pp.189-195
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• 2003

To enhance the reductive dechlorination of polychlorinated biphenyls (PCBs) under anaerobic conditions, we examined the adjunctive effects of cobalt (Co) and nickel (Ni), which are the central metals of transition-metal cofactors of coenzyme F$\_$430/ and vitamin B$\_$12/, respectively, on the dechlorination of Aroclor 1248. After 32 weeks of incubation, the average numbers of chlorines per biphenyl in culture vials supplemented with 0.2, 0.5, and 1.0 mM of Co reduced from 3.88 to 3.39, 2.92, and 3.28, respectively. However, the numbers of chlorine after supplementing with Ni decreased from 3.88 to 3.43, regardless of the Ni concentrations. The observed congener distribution patterns of all vials with different conditions were similar to the pattern produced by the dechlorination process of H' after 21 weeks of incubation, and these patterns were unchanged up to week 32, except for vials supplemented with 0.5 and 1.0 mM of Co. In vials containing 0.5 mM of Co, meta-rich congeners, such as 25/ 25-,24/25-, and 25/23-chlorobiphenyls (CBPs), which were found as accumulated products of dechlorination in other conditions, were further dechlorinated, and 25/2-, 24/2-, and 2/2-CBPs were concomitantly increased after 32 weeks of incubation. In this case, the congener distribution was similar to the dechlorination pattern of process M. From these results, we suggested that the enrichment of cultures with Co might stimulate the growth of specific populations of meta-dechlorinators, and that populations might promote a change in the dechlorination process from H' to M, which is known to be less effective on the dechlorination of the more highly chlorinated congeners of PCBs.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.136-139
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• 2003

The combined effect of bioaugmentation of dechlorinating bacterial cultures and addition of iron powder (Fe$^{0}$ ) on reductive dechlorination of tetrachloroethylene (PCE) and other chlorinated ethylenes in a artificially contaminated soil slurry (60$\mu$mo1es PCE/kg soil) were tested. Two different anaerobic bacterial cultures, a pure bacterial culture of Desulfitobacterium sp. strain Y-51 capable of dechlorinating PCE to cis-1, 2-dechloroethylene (cis-DCE) and the other enrichment culture PE-1 capable of dechlorinating PCE completely to ethylene, were used for the bioaugmentation test. Both treatments introduced with the strain Y-51 and PE-1 culture (3mg dry cell weight/kg soil) showed conversion of PCE to cis-DCE within 40 days. The treatments added with Fe$^{0}$ (0.1 -1.0 %(w/w)) alone to the soil slurry resulted in extended PCE dechlorination to ethylene and ethane and the, dechlorination rate depended on the amount of Fe$^{0}$ added. The combined use of the bacterial cultures with Fe$^{0}$ (0.1-1.0%) showed the higher PCE dechlorination rate than the separated application and the pattern of PCE dechlorination and end-product formation was different from those of the separated application. These results suggested that the combined application of Fe$^{0}$ and the bactrial culture, specially the complete dechlorinating enrichment culture such as PE-1 culture, would be practically effective for remediation of PCE contaminated soil.

• 유기물자원화
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• 제11권2호
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• pp.55-65
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• 2003

인위적인 tetrachloroethylone(PCE) 오염토양($60{\mu}moles$ PCE/kg soil)에서 탈염소화미생물의 주입과 철분($Fe^0$) 첨가의 동시 적용이 PCE 및 유기염소화합물의 환원적 탈염소화에 미치는 영향을 조사하였다. 탈염소화미생물 주입에는 두 종류의 혐기성 박테리아 배양액, 즉, PCE를 cis-1,2-dechloroethylene(cis-DCE)까지 탈염소화하는 Desulfitobacterium sp. Y-51 균주의 순순미생물 배양액과 PCE를 에틸렌까지 완전히 탈염소화하는 PE-1 혼합미생물 배양액을 사용하였다. Y-51균주와 PB-1 혼합미생물 배양액을 각각 적용한 두경우(최종농도: 3mg dry cell weight/kg soil) 모두에서 40일 이내에 PCE가 cis-DCE로 전환되었다. $Fe^0$(0.1-1.0%(w/w))을 단독으로 오염토양에 적용한 경우, PCE의 탈염소화는 에틸렌 및 에탄까지 확장되어 진행되었으며. 탈염소화의 속도는 $Fe^0$의 첨가량에 의존하는 것으로 밝혀졌다. 탈염소화미생물과 철분을 동시에 적용한 경우, 각각을 단독으로 적용한 경우에 비하여 PCE의 탈염소화속도가 빨랐으며, PCE 탈염소화 및 최종 반응생성물의 생성 양상 또한 달랐다. Y-51균주 배양액과 0.1%의 $Fe^0$를 동시에 적용하였을 경우, PCE가 탈염소화되어 cis-DCE를 축적하였지만, PE-1 혼합미생물 배양액과 0.1%의 $Fe^0$를 동시에 적용하였을 경우에는 cis-DCE를 거쳐 보다 확장된 탈염소화반응을 보였다. 이러한 결과들로부터, 탈염소화미생물과 철분의 동시 적용, 특히, PE-1과 같이 PCE를 완전히 탈염소화하는 미생물 배양액과 철분의 병용은 실제적인 PCE 오염토양의 정화에 효과적일 것으로 판단되었다.

• Journal of the Korean Wood Science and Technology
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• 제26권3호
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• pp.53-62
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• 1998

In this research, 7 species of white rot fungi were used for determining the resistance against pentachlorophenol (PCP). Three fungi with good PCP resistance were selected for evaluating the biodegradability, and biodegradation mechanism by HPLC and GC/MS spectrometry. Among 7 fungi, there were significant differences on PCP resistance on 4 different PCP concentrations. In the concentrations of 50 and 100ppm ($\mu$g of PCP per g of 2% malt extract agar), most fungi were easily able to grow, and well suited to newly PCP-added condition, but in that of more than 250ppm, the mycelia growths of Ganoderma lucidum 20435, G. lucidum 20432, Pleurotus ostreatus, and Daldinia concentrica were significantly inhibited or even stopped by the addition of PCP to the culture. However, Trametes versicolor, Phanerochaete chrysosporium, and Inonotus cuticularis still kept growing at 250ppm, indicating the potential utilization of wood rot fungi to high concentrated PCP biodegradation. Particularly, P. chrysosporium even showed very rapid growth rate at more than 500ppm of PCP concentration. Three selected fungi based on the above results showed an excellent biodegradability against PCP. P. chrysosporium degraded PCP up to 84% on the first day of incubation, and during 7 days, most of added PCP were degraded. T. versicolor also showed more than 90% of biodegradability at 7th day, and even though the initial stage of degradation was very slow, I. cuticularis has been approached to 90% at 21 st day after incubation with dense growing pattern of mycelia. Therefore, the PCP biodegradability was definitely dependent on the rapid suitability of fungi to newly PCP-added condition. In addition, the PCP biodegradation by filtrates of P. chrysosporium, T. versicolor, and I. cuticularis was very minimal or limited, suggesting that the extracellular enzyme system may be not so significantly related to the PCP biodegradation. Among the biodegradation metabolites of PCP, the most abundant one was pentachloroanisole which resulted in a little weaker toxicity than PCP, and others were tetrachlorophenol, tetrachloro-hydroquinone, benzoic acid, and salicylic acid, suggesting that PCP may be biodegraded by several sequential reactions such as methylation, radical-induced oxidation, dechlorination, and hydroxylation.