Chen Hui-Lun, Yao Jun, Wang Lin, Wang Fei, Bramanti Emilia, Maskow Thomas, Zaray Gyula
Key Laboratory of Biogeology and Environmental Geology, Chinese Ministry of Education, China University of Geosciences, Wuhan, PR China.
Chemosphere. 2009 Mar;74(10):1407-11. doi: 10.1016/j.chemosphere.2008.11.005. Epub 2008 Dec 11.
Solvent tolerance is important because it allows microorganisms to grow at high concentrations of organic solvents. Organisms capable of surviving under these extreme conditions have great application in bioremediation of contaminated sites. In our study, four strains of Pseudomonas sp. B1 and J2, Acinetobacter sp. B2 and J6 which were isolated from the activated sludge were used to evaluate the solvent tolerance by microcalorimetry. The strains B2 and J2 showed high tolerance to organic solvent as they could grow well in the medium containing 10 vol% of benzene and 70 vol% of toluene, respectively. The higher the growth rate constant, the higher the solvent tolerance of the strains isolated. The microbial growths obtained by microcalorimetry were in good agreement with the results determined by OD(600). The decrease in growth rate constant and the change in total thermal effect in the presence of organic solvents were in agreement with the data reported in the literatures. Strains B1 and B2 degraded about 67% and 94% of 0.1 vol% benzene within 72 h in a medium with benzene as the sole carbon source, respectively. Strains J2 and J6 degraded approximately 92% and 85% of 0.1 vol% toluene within 72 h, respectively. The related degradation genes detected in previous study in these strains highlight an important potential use of those bacteria for the clean-up of benzene and toluene in the environment.
耐溶剂性很重要，因为它使微生物能够在高浓度有机溶剂中生长。能够在这些极端条件下存活的生物在受污染场地的生物修复中具有很大的应用价值。在我们的研究中，从活性污泥中分离出的四株假单胞菌属（菌株B1和J2）、不动杆菌属（菌株B2和J6）用于通过微量热法评估耐溶剂性。菌株B2和J2对有机溶剂表现出高耐受性，因为它们分别能在含有10体积%苯和70体积%甲苯的培养基中良好生长。生长速率常数越高，分离出的菌株的耐溶剂性越高。通过微量热法获得的微生物生长情况与通过OD(600)测定的结果高度一致。在有机溶剂存在下生长速率常数的降低和总热效应的变化与文献报道的数据一致。在以苯为唯一碳源的培养基中，菌株B1和B2在72小时内分别降解了0.1体积%苯的约67%和94%。菌株J2和J6在72小时内分别降解了0.1体积%甲苯的约92%和85%。在先前研究中在这些菌株中检测到的相关降解基因突出了这些细菌在环境中清理苯和甲苯的重要潜在用途。
