title: Exploring metal effects and synergistic interactions of ferric stimulation on azo-dye decolorization by new indigenous Acinetobacter guillouiae Ax-9 and Rahnella aquatilis DX2b.
abstract: The first-attempt study deciphered metal-interacting effects on dye-decolorizing capabilities of indigenous bioelectricity-generating strains, Acinetobacter guillouiae Ax-9 and Rahnella aquatilis DX2b. Most of the metallic ions were inhibitory to color removal capabilities of these strains. However, with supplementation of 5 mM ferric chloride, specific decolorization rate (SDR) of Ax-9 increased by 55.48% compared to Fe(3+)-free conditions. In contrast, SDR of DX2b decreased 75.35% due to the inhibition of ferric chloride. On the other hand, ferric citrate could stimulate SDR of DX2b for 21.5% at same dosage. Enzymatic assay indicated that Fe reductase activity was consistent with synergistic effects of ferric chloride on Ax-9, and ferric citrate on DX2b. Protein analysis via SDS-PAGE and identification of Tandem MS/MS afterwards showed that outer membrane protein (Omp) primarily deals with decolorization as a channeling regulation. Moreover, molecular modeling and bioinformatics data also provided detailed evidences to confirm the biological significance of Omp.
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China, yswu@xmu.edu.cn.
authors.forename: I-Son
authors.initials: IS
authors.lastname: Ng
authors.forename: Fangxin
authors.initials: F
authors.lastname: Xu
authors.forename: Chiming
authors.initials: C
authors.lastname: Ye
authors.forename: Bor-Yann
authors.initials: BY
authors.lastname: Chen
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Lu
mesh_terms: D000150:Acinetobacter / Q000378:metabolism*; D001391:Azo Compounds / Q000737:chemistry*; D003116:Color; D004396:Coloring Agents / Q000737:chemistry*; D019295:Computational Biology; D004591:Electrophoresis, Polyacrylamide Gel; D005290:Ferric Compounds / Q000737:chemistry*; D008958:Models, Molecular; D020638:Rahnella / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D005290:Ferric Compounds