microorganisms Article Effects of Dispersants and Biosurfactants on Crude-Oil Biodegradation and Bacterial Community Succession Gareth E. Thomas 1,* , Jan L. Brant 2 , Pablo Campo 3 , Dave R. Clark 1,4, Frederic Coulon 3 , Benjamin H. Gregson 1, Terry J. McGenity 1 and Boyd A. McKew 1 1 School of Life Sciences, University of Essex, Wivenhoe Park, Essex CO4 3SQ, UK;
[email protected] (D.R.C.);
[email protected] (B.H.G.);
[email protected] (T.J.M.);
[email protected] (B.A.M.) 2 Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, Suffolk NR33 0HT, UK;
[email protected] 3 School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK; p.campo-moreno@cranfield.ac.uk (P.C.); f.coulon@cranfield.ac.uk (F.C.) 4 Institute for Analytics and Data Science, University of Essex, Wivenhoe Park, Essex CO4 3SQ, UK * Correspondence:
[email protected]; Tel.: +44-1206-873333 (ext. 2918) Abstract: This study evaluated the effects of three commercial dispersants (Finasol OSR 52, Slickgone NS, Superdispersant 25) and three biosurfactants (rhamnolipid, trehalolipid, sophorolipid) in crude- oil seawater microcosms. We analysed the crucial early bacterial response (1 and 3 days). In contrast, most analyses miss this key period and instead focus on later time points after oil and dispersant addition. By focusing on the early stage, we show that dispersants and biosurfactants, which reduce Citation: Thomas, G.E.; Brant, J.L.; the interfacial surface tension of oil and water, significantly increase the abundance of hydrocarbon- Campo, P.; Clark, D.R.; Coulon, F.; degrading bacteria, and the rate of hydrocarbon biodegradation, within 24 h.