Effect of bioemulsificant exopolysaccharide (EPS2003) on microbial community dynamics during assays of oil spill bioremediation: A microcosm study

Microcosms experiments were carried out to evaluate the effect of bioemulsificant exopolysaccharide (EPS2003) on microbial community dynamics. An experimental seawater microcosm, supplemented with crude oil and EPS2003 (SW + OIL + EPS2003), was monitored for 15 days and compared to control microcosm (only oil-polluted seawater, SW + OIL). Determination of bacterial abundance, heterotrophic cultivable and hydrocarbon-degrading bacteria were carried out during all experimentation period. The microbial community dynamic was monitored by isolation of total RNA, RT-PCR amplification of 16S rRNA, cloning and sequencing. Oil degradation was monitored by GC MS analysis. Bioemulsificant addition stimulated an increase of the total bacterial abundance, change in the community structure and activity. The bioemulsificant also increased of 5 times the oil biodegradation rate.