| Strong static magnetic field (SSMF,≥1 Tesla) is generated by modern superconducting technology. So far, many novel appearances of organism have been observed as the organisms had been treated with SSMFs, compared with those phenomena observed from other static magnetic fields below 1 T. Based on this, seeking organisms which could respond to the impact of SSMF, and using the SSMF to enhance the pollutant treatment ability of the organisms, were the topics of the paper.To avoid the uncertain disturbance, single-cell magnetotactic bacteria were chosed to be the bridge between a SSMF of 10.0 T and the organic pollutant treatment. With or without the treatment of the SSMF, the physiology and biochemistry information of experimental bacteria were investigated. Additionally, the azoreductase gene, the azoreductase, and the degradation behavior of decolorization strains that could respond to the impact of the SSMF were also tested.First, the impact of the SSMF was investigated by the resistance mutation and the morphology. The results showed that the penicillin resistance mutation rate of E. coli ATCC8739 (E. coli) was rised from 3.04(1/109)to 7.05, 7.36, 13.2, 16.9 and 20.9(1/108), when the strain was exposed to the SSMF for 0.5, 1, 2, 4 and 8 h, respectively. This indicated that the impact of the SSMF changed the information in DNA. Microscopic results showed that there were secretions surrounding the resistance mutation colonies of E. coli-SSMF8 (10.0 T, 8 h), compared with the control group. This indicated that the resistance mechanism of the strain was changed by the impact. On the other hand, although there were also secretions surrounding the resistance mutation colonies of E.coli-UV (UV, 1 min), but the colony appearances of E. coli-SSMF8 and E.coli-UV were not consistent, as they grew on the LB plates. It suggested that the SSMF was a new bacterial mutagen, and the bio-effect of the SSMF was not consistent with that of UV, so did the impact mechanism.Secondly, Fourier transform infrared spectroscopy (FTIR) combined with cluster analysis, deconvolution, and curve fitting was established to study the bio-effect of the SSMF.After characterizing the spectroscopic fingerprints of these bacterial cells with or without the treatment of the SSMF by FTIR spectrograph, the calculation results of cluster analysis indicated that the SSMF had significant effects on E. coli compared with S. aureus, while the strains were exposed to the 10.0 T SSMF for 5, 10, 20, 30, 40, 50 and 60 min, respectively. Difference index (D) demonstrated that the mixed range (15001200 cm-1) were the indication for the bio-effect. FTIR-deconvolution- curve fitting of this major indication region further indicated that the composition and conformation of nucleic acid, protein, and fatty acid in E. coli were altered under the magnetic conditions.The results of FTIR-deconvolution-curve fitting of amideâ… (17001600 cm-1) indicated that the impact did not change the composition of protein secondary structure. However, the contents ofβ-sheet andα-helix decreased, and the content of the totalβ-turn increased, when E. coli was exposed to the 10.0 T SSMF for 0.5, 1, 2, 4 and 8 h, respectively. Additionally, FTIR-cluster analysis also revealed that there was a very clear distinction between DNA molecules with or without the magnetic field treatment. FTIR-deconvolution of feature region (10001800 cm-1) indicated that absorption peaks of cytosine (1650 cm-1) were splited into double, the peak intensity of adenine (1410 cm -1) and the peak area of phosphate group (1240 cm -1) were enhanced, suggesting the bio-effect of SSMF on the DNA molecules.PCR Amplified, molecular cloning and gene sequencing showed that the nucleic acid sequences of azoreductase gene (azoR), the amino acid sequence of azoreductase (AzoR) of E. coli without the SSMF treatment were comfirmed to be identical with that of E.coli ATCC 8739 reported in GenBanK database. While there was a cytosine deletion mutation occurred at the 99th point of the gene in E. coli-SSMF8 (10.0 T, 8 h). The deletion mutation modified the reading frame of azoR and created a novel azoreductase gene azoR-SSMF8, as well as an azoreductase AzoR-SSMF8. The decolorization tests showed that the cells of E. coli-SSMF8 produced much clearer decolorization halo zone than E. coli on the plates containing 500 mg/L ARB (CI14720). Decolorization of the dye broth also indicated that the beginning of decolorization (ts) was put ahead 2 hours, and the maximum decolorization rate (ηmax) was increased 15 %, compared with the control. Dissolved oxygen proved that E. coli-SSMF8 had less sensitive to the oxygen on the dye broth. UV-Vis spectra indicated that the -N=N- was still cleavaged by azoreductase, just liked that of E. coli. Further, the the metabolic pathway of E. coli was changed by the bio-effect.Finally, expand the impact the SSMF to a wild strain B1, which was isolated from soil and identified as Bacillus (Bacillus sp., by the API analysis). After exposure to the 10.0 T SSMF for 20, 30 and 40 min, the activity of cytoplasm azoreductase (AZR) was increased by the impact of the SSMF. The impact did not change the role of the optimal temperature (35℃) and pH (8.0), while inhibiting the activity of AZR from declining substantially out of the optimal areas. FTIR analysis of HB3's AZR (10.0 T, 30 min) showed that theα-helix content was increased, the contents ofβ-fold and L-coil were decreased, compared with that of B1. This indicated that the bio-effect was in charge for genetic modification. The degradation process of the ARG (CIAcid Red 1) by HB3 and B1 was approximated by a reversed S-like curve. A kinetics equation (C = A×exp[-exp(K×(t–tc))]) whose parameters re?ected the degradation process was then established. The comparison and analysis of the kinetics parameters showed that the SSMF enhanced the biodegradation ability of the exposed strain--increasing the value of A (degradation constant) and Vmax(maximum reaction rate) to 1.7 and 1.5 times, respectively, and at the same time, reducing the value of tc(time when the maximum reaction rate was reached) to 0.8 times. Additionally, UV-Vis spectra also showed that the decolorization mechanism was not modified and the metabolic pathway of the bacteria was changed after being exposed to the SSMF.To sum up, SSMF is a new kind of physical mutagen. DNA in vivo is the impact aim of SSMF. Therefor, the azoreductase gene and azoreductase of decolorization bacteria can be changed by the impact of SSMF, and the decolorization ability of the treated strains is enhanced. All of these changes can be detected by methods of biochemistry (penicillin resistance test), physics (FTIR spectroscopy), molecular biology (molecular cloning and gene sequencing), and other means.Additionally, variability is the nature of bacteria. Therefore, using SSMF impaction can obtain novel strains different from those cultured by other traditional chemistry and physics mutagens. From the mutants, strains with high biodegradation ability on specific pollutants can be isolated. This method will be a new interdisciplinary research area in physics and environment subject, and can do better for the natural environment and sustainable development of human society.
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