Schulprojekt-klimawandel.de

Degradation of organic pollutants by bacteria and its potential
application in bioremediation

W. W. Zhang*, Z. L. Niu*, K. Yin*, P. Liu*, L. X. Chen*
* Key Laboratory of Coastal Zone Environmental Processes, Chinese Academy of
Sciences; Shandong Provincial Key Laboratory of Coastal Zone Environmental
Processes; Yantai Institute of Coastal Zone Research, Chinese Academy of
Sciences, NO.17, Chunhui Road, Laishan District, Yantai, Shandong, P.R.China
(E-mail: [email protected]; [email protected]; [email protected];
[email protected]; [email protected])
Abstract
Given the immense risk posed by widespread environmental pollution of inorganic and organic chemicals, novel methods of decontamination and clean-up are required. Owing to the relatively high cost and the non-specificity of conventional techniques, bioremediation is a promising alternative technology for pollutants clean-up. Several bacterial strains, including Enterobacter sp., Acinetobacter sp., Pseudomonas sp. and Proteus sp., that can degrade sulphonamides, estrogen, furazolidone, carbendazim, crude oil and other organic pollutants, and one Pseudomonas sp. strain that can biotransform Hg2+ to Hg0, were isolated and characterized. The degradation activity of the strains was characterized by CE, HPLC or HPLC/MS. After degradation or biotransformation by the isolated bacterial strains, the concentration of the pollutants in the environment was significantly reduced. Cytotoxic analysis showed that the supernatant containing pollutant and/or its metabolites showed distinctly decreased cytotoxicity to HeLa cells, which confirmed the application of the bacteria in the bioremediation. Bacterial glutathione S-transferases (GST) are part of a superfamily of enzymes that play a key role in cellular detoxification, implicated in a variety of
distinct processes such as the biodegradation of xenobiotics, protection against
chemical and oxidative stresses, and antimicrobial drug resistance. GST of
Proteus mirabilis V7 and Acinetobacter calcoaceticus T32 was found to be
involved in the furazolidone-degradation process. GST of P. mirabilis V7 was
found to be involved in the varied tolerance of DDT, diazinon, carbendazim,
trichlorphon, diethylstilbestrol and bromophos ethyl. Another important regulator
in bacterial that controls the expression of genes involved in diverse cellular
functions is the ferric uptake regulator (Fur). In our study, real-time PCR
demonstrated that Fur of Pseudomonas aeruginosa PA1 was a repressor during
the degradation of thionphosphate, bromophos ethyl, and to certain extent
diethylstilbestrol.
Keywords: bacteria; degradation; environmental pollution; cytotoxicity; GST;
Fur

Source: http://www.schulprojekt-klimawandel.de/imperia/md/content/loicz/osc/d3-weiwei-zhang.pdf