[1] PHOENIX V R, HOLMES W M. Magnetic resonance imaging of structure, diffusivity, and copper immobilization in a phototrophic biofilm [J]. Applied and Environmental Microbiology, 2008, 74(15): 4934-4943. doi: 10.1128/AEM.02783-07
[2] JOE J H, HOWARD C, RAYMOND J T. Multimetal resistance and tolerance in microbial biofilms [J]. Nature Reviews Microbiology, 2007, 5(12): 928-938. doi: 10.1038/nrmicro1774
[3] YAO Y J, SHEN R, PENNELL K G, et al. Examination of the influence of environmental factors on contaminant vapor concentration attenuation factors using the US EPA's vapor intrusion database [J]. Environmental Science & Technology, 2013, 47(2): 906-913.
[4] HOLDEN P A, HUNT J R, FIRESTONE M K. Toluene diffusion and reaction in unsaturated Pseudomonas putida biofilms [J]. Biotechnology and Bioengineering, 1997, 56(6): 656-670. doi: 10.1002/(SICI)1097-0290(19971220)56:6<656::AID-BIT9>3.0.CO;2-M
[5] MERCAN DOGAN N, KANTAR C, DOGAN G. Effect of chromium and organic acids on microbial growth and exopolymeric substance production by Pseudomonas Bacteria [J]. Clean Soil Air Water, 2014, 42(5): 674-681. doi: 10.1002/clen.201300158
[6] STEINBERGER R E, ALLEN A R, HANSMA H G, et al. Elongation correlates with nutrient deprivation in Pseudomonas aeruginosa unsaturated biofilms [J]. Microbial Ecology, 2002, 43(4): 416-423. doi: 10.1007/s00248-001-1063-z
[7] JEFFERSON K K. What drives bacteria to produce a biofilm? [J]. FEMS Microbiology Letters, 2004, 236(2): 163-173. doi: 10.1111/j.1574-6968.2004.tb09643.x
[8] CHANG W S, VAN M, NIELSEN L, et al. Alginate production by Pseudomonas putida creates a hydrated microenvironment and contributes to biofilm architecture and stress tolerance under water-limiting conditions [J]. Journal of Bacteriology, 2007, 189(22): 8290-8299. doi: 10.1128/JB.00727-07
[9] ZHANG Z J, CHEN S H, WANG S M, et al. Characterization of extracellular polymeric substances from biofilm in the process of starting-up a partial nitrification process under salt stress [J]. Applied Microbiology and Biotechnology, 2011, 89(5): 1563-1571. doi: 10.1007/s00253-010-2947-y
[10] SHENG G P, YU H Q, YUE Z B. Production of extracellular polymeric substances from Rhodopseudomonas acidophila in the presence of toxic substances [J]. Applied Microbiology and Biotechnology, 2005, 69(2): 216-222. doi: 10.1007/s00253-005-1990-6
[11] PRIESTER J H, OLSON S G, WEBB S M, et al. Enhanced exopolymer production and chromium stabilization in Pseudomonas putida unsaturated biofilms [J]. Applied and Environmental Microbiology, 2006, 72(3): 1988-1996. doi: 10.1128/AEM.72.3.1988-1996.2006
[12] SHARMA J, SHAMIM K, DUBEY S K. Phosphatase mediated bioprecipitation of lead as pyromorphite by Achromobacter xylosoxidans [J]. Journal of Environmental Management, 2018, 217: 754-761. doi: 10.1016/j.jenvman.2018.04.027
[13] HOU W, MA Z, SUN L, et al. Extracellular polymeric substances from copper-tolerance Sinorhizobium meliloti immobilize Cu2+ [J]. Journal of Hazardous Materials, 2013, 261: 614-620. doi: 10.1016/j.jhazmat.2013.06.043
[14] SUTHERLAND I. Biofilm exopolysaccharides: A strong and sticky framework [J]. Microbiology (Reading, England), 2001, 147(1): 3-9. doi: 10.1099/00221287-147-1-3
[15] BURGOS W D, SENKO J M, DEMPSEY B A, et al. Soil humic acid decreases biological uranium (Ⅵ) reduction by Shewanella putrefaciens CN32 [J]. Environmental Engineering Science, 2007, 24(6): 755-761. doi: 10.1089/ees.2006.0009
[16] PAUL C C, STONE J J. Effects of nickel and soil humic acid during biological hematite reduction by Shewanella putrefaciens CN32 [J]. Environmental Engineering Science, 2009, 26(4): 841-848. doi: 10.1089/ees.2008.0254
[17] BURKHARDT E M, BISCHOFF S, AKOB D M, et al. Heavy metal tolerance of Fe(Ⅲ)-reducing microbial communities in contaminated creek bank soils [J]. Applied and Environmental Microbiology, 2011, 77(9): 3132-3136. doi: 10.1128/AEM.02085-10
[18] LIU L C, LIU G F, ZHOU J T, et al. Improved bioreduction of nitrobenzene by black carbon/biochar derived from crop residues [J]. RSC Advances, 2016, 6(87): 84388-84396. doi: 10.1039/C6RA11671J
[19] AUERBACH I D, SORENSEN C, HANSMA H G, et al. Physical morphology and surface properties of unsaturated Pseudomonas putida biofilms [J]. Journal of Bacteriology, 2000, 182(13): 3809-3815. doi: 10.1128/JB.182.13.3809-3815.2000
[20] LIN H R, CHEN G C, LONG D Y, et al. Responses of unsaturated Pseudomonas putida CZ1 biofilms to environmental stresses in relation to the EPS composition and surface morphology [J]. World Journal of Microbiology and Biotechnology, 2014, 30(12): 3081-3090. doi: 10.1007/s11274-014-1735-8
[21] AGUILERA A, SOUZA-EGIPSY V, SAN MARTÍN-ÚRIZ P, et al. Extraction of extracellular polymeric substances from extreme acidic microbial biofilms [J]. Applied Microbiology and Biotechnology, 2008, 78(6): 1079-1088. doi: 10.1007/s00253-008-1390-9
[22] DUBOIS M, GILLES K A, HAMILTON J K, et al. Colorimetric method for determination of sugars and related substances [J]. Analytical Chemistry, 1956, 28(3): 350-356. doi: 10.1021/ac60111a017
[23] BRADFORD M M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding [J]. Analytical Biochemistry, 1976, 72: 248-254. doi: 10.1016/0003-2697(76)90527-3
[24] LONG D Y, ZOU L N, HASHMI M Z, et al. Determination of the accumulation, spatial distribution and reduction of Cr in unsaturated Pseudochrobactrum saccharolyticum LY10 biofilms by X-ray fluorescence and absorption methods [J]. Chemical Engineering Journal, 2015, 280: 763-770. doi: 10.1016/j.cej.2015.06.013
[25] URONE P F. Stability of colorimetric reagent for chromium, s-diphenylcarbazide, in various solvents [J]. Analytical Chemistry, 1955, 27(8): 1354-1355. doi: 10.1021/ac60104a048
[26] LIU J, YANG Q, WANG D, et al. Enhanced dewaterability of waste activated sludge by Fe(Ⅱ)-activated peroxymonosulfate oxidation [J]. Bioresource Technology, 2016, 206: 134-140. doi: 10.1016/j.biortech.2016.01.088
[27] YUE Z B, LI Q, LI C C, et al. Component analysis and heavy metal adsorption ability of extracellular polymeric substances (EPS) from sulfate reducing bacteria [J]. Bioresource Technology, 2015, 194: 399-402. doi: 10.1016/j.biortech.2015.07.042
[28] JAMES G A, KORBER D R, CALDWELL D E, et al. Digital image analysis of growth and starvation responses of a surface-colonizing Acinetobacter sp [J]. Journal of Bacteriology, 1995, 177(34): 907-915.
[29] REVA O N, WEINEL C, WEINEL M, et al. Functional genomics of stress response in Pseudomonas putida KT2440 [J]. The Journal of Bacteriology, 2006, 188(11): 4079-4092. doi: 10.1128/JB.00101-06
[30] ZHANG L L, CHEN X, CHEN J M, et al. Role mechanism of extracellular polymeric substances in the formation of aerobic granular sludge [J]. Chinese Journal of Environmental Science, 2007, 28(4): 795-799.
[31] MIDDLETON S S, LATMANI R B, MACKEY M R, et al. Cometabolism of Cr(VI) by Shewanella oneidensis MR-1 produces cell-associated reduced chromium and inhibits growth [J]. Biotechnology and Bioengineering, 2003, 83(6): 627-637. doi: 10.1002/bit.10725
[32] TENG Z, SHAO W, ZHANG K, et al. Pb biosorption by Leclercia adecarboxylata: Protective and immobilized mechanisms of extracellular polymeric substances [J]. Chemical Engineering Journal, 2019, 375: 122113. doi: 10.1016/j.cej.2019.122113
[33] KONG S, YONGE D R, JOHNSTONE D L, et al. Chromium distribution in subcellular components between fresh and starved subsurface bacterial consortium [J]. Biotechnology Letters, 1992, 14(6): 521-524. doi: 10.1007/BF01023179
[34] SHENG G P, XU J, LUO H W, et al. Thermodynamic analysis on the binding of heavy metals onto extracellular polymeric substances (EPS) of activated sludge [J]. Water Research, 2013, 47(2): 607-614. doi: 10.1016/j.watres.2012.10.037
[35] CHEN W, WESTERHOFF P, LEENHEER J A, et al. Fluorescence excitation-emission matrix regional integration to quantify spectra for dissolved organic matter [J]. Environmental Science & Technology, 2003, 37(24): 5701-5710.
[36] ZHU L, QI H Y, LV M L, et al. Component analysis of extracellular polymeric substances (EPS) during aerobic sludge granulation using FTIR and 3D-EEM technologies [J]. Bioresource Technology, 2012, 124: 455-459. doi: 10.1016/j.biortech.2012.08.059
[37] WANG Z, GAO M, WANG S, et al. Effect of hexavalent chromium on extracellular polymeric substances of granular sludge from an aerobic granular sequencing batch reactor [J]. Chemical Engineering Journal, 2014, 251: 165-174. doi: 10.1016/j.cej.2014.04.078