title: Visualizing acidophilic microorganisms in biofilm communities using acid stable fluorescence dyes.
abstract: Bacteria in acidophilic biofilm communities, i.e. acid streamers and snottites, obtained from a subsurface mine in Königstein were visualized by fluorescence microscopy using four new fluorescent dyes (DY-601XL, V07-04118, V07-04146, DY-613). The pH of the bulk solution in which these bacteria thrive was pH 2.6 to 2.9. The new fluorescent dyes were all able to clearly stain and microscopically visualize in-situ the bacteria within the biofilm community without changing pH or background ion concentration. The commonly used fluorescent dyes DAPI and SYTO 59 were also applied for comparison. Both dyes, however, were not able to visualize any bacteria in-situ, since they were not stable under the very acid conditions. In addition, dye V07-04118 and dye DY-613 also possess the ability to stain larger cells which were presumably eukaryotic origin and may be attributed to yeast cells or amoeba-like cells. PCR analyses have shown that the dominant bacterial species in these acidophilic biofilm communities was a gram negative bacterium of the species Ferrovum myxofaciens. The presented four new dyes are ideal for in-situ investigations of microorganisms occurring in very acid conditions, e.g. in acidophilic biofilm communities when in parallel information on pH sensitive incorporated fluorescent heavy metals should be acquired.
authors.affiliation: Radiochemistry, Technical University Dresden, 01062, Dresden, Germany. s.brockmann@fzd.de
authors.forename: Sina
authors.initials: S
authors.lastname: Brockmann
authors.forename: Thuro
authors.initials: T
authors.lastname: Arnold
authors.forename: Bernd
authors.initials: B
authors.lastname: Schweder
authors.forename: Gert
authors.initials: G
authors.lastname: Bernhard
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D018407:Bacterial Physiological Phenomena; D018441:Biofilms; D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000737:chemistry; D057054:Molecular Imaging / Q000379:methods*; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D019216:Metals, Heavy
references.citation: Annu Rev Microbiol. 1995;49:711-45
references.pmid: 8561477
references.citation: Environ Sci Technol. 2009 Aug 15;43(16):6138-44
references.pmid: 19746704
references.citation: Appl Environ Microbiol. 2006 Aug;72(8):5325-30
references.pmid: 16885283
references.citation: Appl Environ Microbiol. 2005 Oct;71(10):6319-24
references.pmid: 16204553
references.citation: Aquat Toxicol. 2008 Jul 30;88(4):257-66
references.pmid: 18554732
references.citation: Appl Environ Microbiol. 2009 Feb;75(3):858-61
references.pmid: 19047391
references.citation: Naturwissenschaften. 2009 Aug;96(8):963-74
references.pmid: 19504056
references.citation: Appl Environ Microbiol. 2009 Apr;75(7):2192-9
references.pmid: 19201960
references.citation: Appl Environ Microbiol. 2000 Nov;66(11):4962-71
references.pmid: 11055950
references.citation: Biotechnol Bioeng. 1994 May;43(11):1131-8
references.pmid: 18615526
references.citation: Microb Ecol. 2001 Jan;41(1):20-35
references.pmid: 11252161
references.citation: Extremophiles. 2004 Dec;8(6):463-73
references.pmid: 15635484
references.citation: Appl Environ Microbiol. 2000 Sep;66(9):3842-9
references.pmid: 10966399
references.citation: Curr Microbiol. 2009 Jul;59(1):71-7
references.pmid: 19319595
references.citation: ISME J. 2009 Feb;3(2):266-70
references.pmid: 18843299
references.citation: Appl Environ Microbiol. 2006 Mar;72(3):2022-30
references.pmid: 16517651
references.citation: J Bacteriol. 1991 Oct;173(20):6558-67
references.pmid: 1917879