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Culture dependent and independent analyses of bacterial communities involved in copper plumbing corrosion
Author(s) -
Pavissich J.P.,
Vargas I.T.,
González B.,
Pastén P.A.,
Pizarro G.E.
Publication year - 2010
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2010.04704.x
Subject(s) - betaproteobacteria , biofilm , copper , corrosion , microbiology and biotechnology , biology , bacteria , terminal restriction fragment length polymorphism , copper toxicity , 16s ribosomal rna , restriction fragment length polymorphism , metallurgy , materials science , biochemistry , polymerase chain reaction , gene , actinobacteria , genetics
Aims: This study used culture‐dependent and culture‐independent approaches to characterize bacterial communities in copper plumbing corrosion and to assess biofilm formation and copper resistance of heterotrophic bacteria isolated from copper pipes. Methods and Results: Water and copper pipes were collected from a cold‐water household distribution system affected by ‘blue water’ corrosion and presenting biofilm formation. Corrosion‐promoting ageing experiments were performed with conditioned unused copper pipes filled with unfiltered and filtered sampled water as nonsterile and sterile treatments, respectively. During 8 weeks, stagnant water within the pipes was replaced with aerated fresh water every 2 or 3 days. Total copper and pH were determined in sampled water, and copper pipe coupons were cut for microscopic analyses. Biofilms were extracted from field and laboratory pipes, and total DNA was isolated. Bacterial communities’ composition was analysed by terminal restriction fragment length polymorphism (T‐RFLP) and clonal libraries of 16S rRNA genes. Heterotrophic bacterial isolates were obtained from water and biofilm extracts and characterized in terms of biofilm formation capacity and copper minimum inhibitory concentration. The results indicated that copper concentration in stagnant water from nonsterile treatments was much higher than in sterile treatments and corrosion by‐products structure in coupon surfaces was different. Multivariate analysis of T‐RFLP profiles and clone sequencing showed significant dissimilarity between field and laboratory biofilm communities, and a low richness and the dominant presence of Gamma‐ and Betaproteobacteria in both cases. Several bacterial isolates formed biofilm and tolerated high copper concentrations. Conclusions: The study demonstrates microbially influenced corrosion (MIC) in copper plumbing. Gamma‐ and Betaproteobacteria dominated the corroded copper piping bacterial community, whose ability to form biofilms may be important for bacterial corrosion promotion and survival in MIC events. Significance and Impact of the Study: The characterization of micro‐organisms that influence copper plumbing corrosion has significant implications for distribution system management and copper corrosion control.