title: Decolorization of textile azo dye and Congo red by an isolated strain of the dissimilatory manganese-reducing bacterium Shewanella xiamenensis BC01.
abstract: Shewanella xiamenensis BC01 (SXM) was isolated from sediment collected off Xiamen, China and was identified based on the phylogenetic tree of 16S rRNA sequences and the gyrB gene. This strain showed high activity in the decolorization of textile azo dyes, especially methyl orange, reactive red 198, and recalcitrant dye Congo red, decolorizing at rates of 96.2, 93.0, and 87.5%, respectively. SXM had the best performance for the specific decolorization rate (SDR) of azo dyes compared to Proteus hauseri ZMd44 and Aeromonas hydrophila NIU01 strains and had an SDR similar to Shewanella oneidensis MR-1 in Congo red decolorization. Luria-Bertani medium was the optimal culture medium for SXM, as it reached a density of 4.69 g-DCW L(-1) at 16 h. A mediator (manganese) significantly enhanced the biodegradation and flocculation of Congo red. Further analysis with UV-VIS, Fourier Transform Infrared spectroscopy, and Gas chromatography-mass spectrometry demonstrated that Congo red was cleaved at the azo bond, producing 4,4'-diamino-1,1'-biphenyl and 1,2'-diamino naphthalene 4-sulfonic acid. Finally, SEM results revealed that nanowires exist between the bacteria, indicating that SXM degradation of the azo dyes was coupled with electron transfer through the nanowires. The purpose of this work is to explore the utilization of a novel, dissimilatory manganese-reducing bacterium in the treatment of wastewater containing azo dyes.
authors: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China, yswu@xmu.edu.cn.
authors: I-Son
authors: IS
authors: Ng
authors: Tingting
authors: T
authors: Chen
authors: Rong
authors: R
authors: Lin
authors: Xia
authors: X
authors: Zhang
authors: Chao
authors: C
authors: Ni
authors: Dongzhe
authors: D
authors: Sun
mesh_terms: D016980:Aeromonas hydrophila / Q000378:metabolism; D001391:Azo Compounds / Q000378:metabolism*; D002681:China; D002849:Chromatography, Gas; D016000:Cluster Analysis; D004396:Coloring Agents / Q000378:metabolism*; D003224:Congo Red / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D027081:DNA Gyrase / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008345:Manganese / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D053770:Nanowires / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010802:Phylogeny; D011511:Proteus / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D020592:Shewanella / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013784:Textiles
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D003224:Congo Red; D008345:Manganese; D027081:DNA Gyrase