Ouyang Shao-Ping, Liu Qian, Sun Shang-Yu, Chen Jin-Chun, Chen Guo-Qiang
Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China.
J Biotechnol. 2007 Nov 1;132(3):246-50. doi: 10.1016/j.jbiotec.2007.08.001. Epub 2007 Aug 6.
Toluene dioxygenase (TDO) catalyzes asymmetric cis-dihydroxylations of aromatic compounds. Pseudomonas putida KT2442 (pSPM01) harboring TDO genes could effectively biotransform a wide-range of aromatic substrates into their cis-diols products. In shake-flask culture, approximately 2.7gl(-1) benzene cis-diols, 8.8gl(-1) toluene cis-diols and 6.0gl(-1) chlorobenzene cis-diols were obtained from the biotransformation process. Furthermore, vgb gene encoding Vitreoscilla hemoglobin protein (VHb) which enhances oxygen microbial utilization rate under low dissolved oxygen concentration was integrated into P. putida KT2442 genome. The oxidation ability of the mutant strain P. putida KTOY02 (pSPM01) harboring TDO gene was increased in the presence of VHb protein. As a result, approximately 3.8, 15.1 or 6.8gl(-1) different cis-diols production was achieved in P. putida KTOY02 (pSPM01) grown in shake-flasks when benzene, toluene or chlorobenzene was used as the substrate. The above results indicate that P. putida KT2442 could be used as a cell factory to biotransform aromatic compounds.
甲苯双加氧酶（TDO）催化芳香族化合物的不对称顺式二羟基化反应。携带TDO基因的恶臭假单胞菌KT2442（pSPM01）能够有效地将多种芳香族底物生物转化为其顺式二醇产物。在摇瓶培养中，通过生物转化过程可获得约2.7g/L的苯顺式二醇、8.8g/L的甲苯顺式二醇和6.0g/L的氯苯顺式二醇。此外，将编码透明颤菌血红蛋白蛋白（VHb）的vgb基因整合到恶臭假单胞菌KT2442基因组中，该蛋白可在低溶解氧浓度下提高氧气微生物利用率。在VHb蛋白存在的情况下，携带TDO基因的突变菌株恶臭假单胞菌KTOY02（pSPM01）的氧化能力增强。结果，当以苯、甲苯或氯苯为底物时，在摇瓶中培养的恶臭假单胞菌KTOY02（pSPM01）中可分别实现约3.8g/L、15.1g/L或6.8g/L的不同顺式二醇产量。上述结果表明，恶臭假单胞菌KT2442可作为生物转化芳香族化合物的细胞工厂。
