In this work, the degradation potentials of different microorganisms,
including bacterial isolates and metagenomic clones,
derived from petroleum reservoirs were evaluated in microcosm
assays using crude oil as a substrate. Chemical analyses demonstrated
biodegradation rates higher than 99% for saturated hydrocarbons
and aromatic compounds for some microorganisms
assessed when compared to the control after only 21 days. The
most efficient microorganisms for n-alkane and isoprenoid degradation
were represented by the metagenomic clones 2B and 1Aand the bacterial isolates Dietzia maris CBMAI 705 and Micrococcus
sp. CBMAI 636. Furthermore, a considerably high biodegradation
potential was confirmed in the biodegradation of phenanthrene
and methylphenanthrenes, mainly for the metagenomic clones
2B and 10A and the bacterial strains Dietzia maris CBMAI 705
and Micrococcus sp. CBMAI 636. However, all microorganisms
showed low efficiency for the degradation of terpanes. Finally, it
is worth highlighting the outstanding performance of clones 2B,
1A and 10A for crude oil degradation, considering that in this case,
the degradation genes are working in a heterologous host. This
work reports innovative results for hydrocarbon degradation by
using genetic resources from petroleum reservoirs, opening perspectives
for their future use in bioremediation strategies in oil
impacted areas.