Interaction of Desulfovibrio desulfuricans biofilms with stainless steel surface and its impact on bacterial metabolism.
OBJECTIVE
To study the influence of some metallic elements of stainless steel 304 (SS 304) on the development and activity of a sulfate-reducing bacterial biofilm, using as comparison a reference nonmetallic material polymethylmethacrylate (PMMA).


RESULTS
Desulfovibrio desulfuricans biofilms were developed on SS 304 and on a reference nonmetallic material, PMMA, in a flow cell system. Steady-state biofilms were metabolically more active on SS 304 than on PMMA. Activity tests with bacteria from both biofilms at steady state also showed that the doubling time was lower for bacteria from SS 304 biofilms. The influence of chromium and nickel, elements of SS 304 composition, was also tested on a cellular suspension of Des. desulfuricans. Nickel decreased the bacterial doubling time, while chromium had no significant effect.


CONCLUSIONS
The following mechanism is hypothesized: a Des. desulfuricans biofilm grown on a SS 304 surface in anaerobic conditions leads to the weakening of the metal passive layer and to the dissolution in the bulk phase of nickel ions that have a positive influence on the sulfate-reducing bacteria metabolism. This phenomenon may enhance the biocorrosion process.


CONCLUSIONS
A better understanding of the interactions between metallic surfaces such as stainless steel and bacteria commonly implied in the corrosion phenomena which is primordial to fight biocorrosion.
Lopes
F A
FA
Centro de Engenharia Biológica, Universidade do Minho, Braga, Portugal. fil.lopes@free.fr
Morin
P
P
Oliveira
R
R
Melo
L F
LF
D000085:Acetates / Q000378:metabolism; D001422:Bacterial Adhesion; D018441:Biofilms; D002857:Chromium / Q000494:pharmacology; D003343:Corrosion; D045285:Desulfovibrio desulfuricans / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D007501:Iron / Q000494:pharmacology; D019344:Lactic Acid / Q000378:metabolism; D009532:Nickel / Q000494:pharmacology; D019904:Polymethyl Methacrylate; D013193:Stainless Steel / Q000737:chemistry*; D013431:Sulfates / Q000378:metabolism
D000085:Acetates; D013431:Sulfates; D002857:Chromium; D013193:Stainless Steel; D019344:Lactic Acid; D009532:Nickel; D019904:Polymethyl Methacrylate; D007501:Iron