Mitigation of the Desulfovibrio vulgaris biofilm using alkyldimethylbenzylammonium chloride enhanced by D-amino acids

D-tyrosine and D-methionine that are naturally occurring chemicals were investigated as enhancers for alkyldimethylbenzylammonium chloride (ADBAC) against the Desulfovibrio vulgaris biofilm on C1018 coupons surfaces in ATCC 1249 culture medium. The 7-day biofilm prevention results showed that the D-amino acids alone had only limited effects on SRB sessile cell counts. Ten ppm (w/w) ADBAC alone achieved a 1-log reduction in SRB sessile cell count compared with the untreated control. The combination of 1 ppm D-tyrosine + 10 ppm ADBAC achieved 3 extra log reduction and 50 ppm D-methionine + 10 ppm ADBAC achieved 2 extra log reduction compared with the 10 ppm ADBAC alone treatment. In the biofilm removal test, both combinations exhibited 2 extra log reduction compared with the 10 ppm ADBAC alone treatment. These results were supported by scanning electron microscope images and confocal laser scanning microscope images of the biofilms. (C) 2016 Elsevier Ltd. All rights reserved.