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Isolation of Bacterial Consortia that Induced Corrosion of Zirconium Alloys

Author:
Stancu, Mihaela Marilena
Source:
Water, air, and soil pollution 2019 v.230 no.2 pp. 38
ISSN:
0049-6979
Subject:
Achromobacter, Citrobacter braakii, Citrobacter freundii, Citrobacter youngae, DNA fingerprinting, Pseudomonas aeruginosa, Pseudomonas putida, alloys, biofilm, carbon, corrosion, sulfate-reducing bacteria, zirconium
Abstract:
The aim of the present study was to isolate several bacterial consortia from a soil sample and to establish if they could colonize zirconium-tin alloy, such as Zircaloy-4. Two bacterial consortia containing aerobic heterotrophic bacteria and anaerobic sulfate-reducing bacteria were isolated from a soil sample. The aerobic heterotrophic bacteria exhibited a higher capability to utilize different sole carbon sources, as compared with anaerobic sulfate-reducing bacteria. Based on a morphological, biochemical, and molecular analysis, bacterial isolates were identified as Pseudomonas putida IBBHA₁, Pseudomonas aeruginosa IBBHA₂, Achromobacter spanius IBBHA₃, Citrobacter freundii IBBSR₁, Citrobacter youngae IBBSR₂, and Citrobacter braakii IBBSR₃. Isolated bacterial consortia which possess distinct DNA fingerprints were able to form biofilms and colonize the surface of zirconium-tin alloy coupons, although the colonization of coupons by the aerobic heterotrophic bacteria or anaerobic sulfate-reducing bacteria alone was lower compared with that observed when the coupon was immersed in a mixture of both bacterial consortia. Coupons immersed in these bacterial consortia revealed changes in the surface characteristics, which can facilitate or accelerate zirconium-tin alloy corrosion. The accumulation of corrosion products on coupons surface was less significant when the coupons were immersed solely in aerobic heterotrophic bacteria or anaerobic sulfate-reducing bacteria, compared with that observed when the coupon was immersed in a mixture of both bacterial consortia.
Agid:
6279980