Habe H, Ide K, Yotsumoto M, Tsuji H, Hirano H, Widada J, Yoshida T, Nojiri H, Omori T
Biotechnology Research Center, The University of Tokyo, Japan.
Appl Microbiol Biotechnol. 2001 Sep;56(5-6):788-95. doi: 10.1007/s002530100707.
A method for bioremediation of chlorinated dibenzo-p-dioxins (CDDs) and dibenzofurans (CDFs) by a carbazole-utilizing bacterium, Pseudomonas sp. strain CA10, was developed. CA10 cells transferred to carbon- and nitrogen-free mineral medium supplemented with 1 mg carbazole (CAR)/ml grew rapidly during the first 2 days; and the cells at the end of this rapid growth period showed the highest 2,3-dichlorodibenzo-p-dioxin (2,3-Cl2DD)-degrading activity. The CA10 cells pregrown for 2 days efficiently degraded 2,3-Cl2DD in aqueous solution at either 1 ppm or 10 ppm. The effect of inoculum density on the efficiency of 2,3-Cl2DD degradation was investigated in a soil slurry microcosm [ratio of soil:water = 1:5 (w/v)]. The results showed that a single inoculation with CA10 cells at densities of 10(7) CFU/g soil and 10(9) CFU/g soil degraded 46% and 80% of 2,3-Cl2DD, respectively, during the 7-day incubation. The rate of degradation of each CDD congener, 2-ClDD, 2,3-Cl2DD, and 1,2,3-Cl3DD (1 ppm each) by strain CA10 in the soil slurry system was not significantly influenced by the coexistence of the other congeners. Using this soil slurry system, we tried an experimental bioremediation of the actual dioxin-contaminated soil, which contained mainly tetra- to octochlorinated dioxins. Although the degradation rate of total CDD and CDF congeners by a single inoculation with CA10 cells was 8.3% after a 7-day incubation, it was shown that strain CA10 had a potential to degrade tetra- to hepta-chlorinated congeners including the most toxic compound, 2,3,7,8-tetrachlorinated dibenzo-p-dioxin.
开发了一种利用咔唑的细菌——假单胞菌属CA10菌株对氯代二苯并 - 对二恶英（CDDs）和二苯并呋喃（CDFs）进行生物修复的方法。将CA10细胞转移至补充有1 mg咔唑（CAR）/ml的无碳无氮矿物培养基中，在前两天内生长迅速；在此快速生长期结束时的细胞表现出最高的2,3 - 二氯二苯并 - 对二恶英（2,3 - Cl2DD）降解活性。预培养2天的CA10细胞能有效降解水溶液中1 ppm或10 ppm的2,3 - Cl2DD。在土壤泥浆微宇宙[土壤：水 = 1:5（w/v）]中研究了接种密度对2,3 - Cl2DD降解效率的影响。结果表明，在7天的培养期内，以10⁷ CFU/g土壤和10⁹ CFU/g土壤的密度单次接种CA10细胞，分别降解了46%和80%的2,3 - Cl2DD。在土壤泥浆系统中，菌株CA10对每种CDD同系物（2 - ClDD、2,3 - Cl2DD和1,2,3 - Cl3DD，每种1 ppm）的降解速率不受其他同系物共存的显著影响。利用该土壤泥浆系统，我们尝试对实际受二恶英污染的土壤进行实验性生物修复，该土壤主要含有四至八氯代二恶英。尽管在7天的培养期后，单次接种CA10细胞对总CDD和CDF同系物的降解率为8.3%，但结果表明菌株CA10有潜力降解包括毒性最大的化合物2,3,7,8 - 四氯二苯并 - 对二恶英在内的四至七氯代同系物。
