The Application of XDLVO Theory in Modeling Sulfate Reducing Bacteria (SRB) Adhesion on Collector Surfaces: Insight into the Initial Events of Biofilm Adhesion

摘要

In this paper, the application of Extended Derjaguin, Landau, Verwey, Overbeek (XDLVO) theory to elucidate the initial events in sulfate reducing bacteria (SRB) adhesion to various collector surfaces leading to biofilm formation was studied. Desulfovibrio (D.) desulfuricans, D. singaporenus, and Marine SRB isolates were used as model bacteria, with stainless steel (SS) and Aluminum 1100 as collector surfaces. The interaction between SRB, and FeS2, Fe2O3, and Al2O3 was also investigated to determine the effect of scales in biofilm formation. The adhesion energy between D. desulfuricans and D. singaporenus, and a conditioned SS steel surface was higher than that of an unconditioned surface; -9.68×10~(-14) to -9.40×10~(-14) J and -49.9×10~(-18) to -194×10~(-18) J, respectively. The interaction between the Marine SRB isolate and Al 1100 was the highest (-14.9x10~(-14)J) compared to that of D. desulfuricans (-9.31 × 10~(-14) J). Furthermore, the model predicted that while the interaction been Al2O3 and Fe2O3, and SRB was not thermodynamically favorable, D. desulfuricans and 0. singaporenus can form biofilm on the surface of pyrite (FeS2) with corresponding adhesion energy values of -130×10~(-18)J and -49.9×10~(-18) J, respectively. Therefore, this suggests these bacteria can readily attach and develop a biofilm on the stainless steel, aluminum as well as on sulfide scales.