چکیده (انگلیسی):

tStreptomyces lunalinharesii strain 235 produces an antimicrobial substance that is activeagainst sulfate reducing bacteria, the major bacterial group responsible for biofilm forma-tion and biocorrosion in petroleum reservoirs. The use of this antimicrobial substance forsulfate reducing bacteria control is therefore a promising alternative to chemical biocides.In this study the antimicrobial substance did not interfere with the biofilm stability, but thesulfate reducing bacteria biofilm formation was six-fold smaller in carbon steel couponstreated with the antimicrobial substance when compared to the untreated control. A reduc-tion in the most probable number counts of planktonic cells of sulfate reducing bacteriawas observed after treatments with the sub-minimal inhibitory concentration, minimalinhibitory concentration, and supra-minimal inhibitory concentration of the antimicro-bial substance. Additionally, when the treated coupons were analyzed by scanning electronmicroscopy, the biofilm formation was found to be substantially reduced when the supra-minimal inhibitory concentration of the antimicrobial substance was used. The couponsused for the biofilm formation had a small weight loss after antimicrobial substance treat-ment, but corrosion damage was not observed by scanning electron microscopy. The absenceof the dsrA gene fragment in the scraped cell suspension after treatment with the supra-minimal inhibitory concentration of the antimicrobial substance suggests that Desulfovibrioalaskensis was not able to adhere to the coupons. This is the first report on an antimicrobialsubstance produced by Streptomyces active against sulfate reducing bacteria biofilm forma-tion. The application of antimicrobial substance as a potential biocide for sulfate reducingbacteria growth control could be of great interest to the petroleum industry.© 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. This isan open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).