Biofilms constructed for the removal of hydrocarbon pollutants from hypersaline liquids.

Abstract

Hydrocarbonoclastic biofilms were established on sterile glass plates vertically submerged for 1 month in a hypersaline soil/water suspension containing 0.3% crude oil. The culture-dependent analysis of the microbial community in those biofilms revealed hydrocarbonoclastic species in the magnitude of 10(3) cells cm(-2). Those species belonged to the halophilic bacterial genera Marinobacter, Halomonas, Dietzia, Bacillus, Arhodomonas, Aeromonas and Kocuria as well as to the haloarchaeal genera Haloferax and Halobacterium. Those organisms were not evenly distributed over the biofilm surface area. The culture-independent analysis revealed a different community composition, which was based on four uncultured and four cultured taxa. Depending on the culture conditions and the sort of chemical amendments, the biofilms succeeded in removing in 2 weeks up to about 60-70% of crude oil, pure n-hexadecane and pure phenanthrene in hypersaline pond water samples. The amendment with KCl, MgSO4 and a vitamin mixture composed of thiamin, pyridoxine, vitamin B12, biotin, riboflavin and folic acid was most effective.