The aim of this work was to investigate the effect
of autochthonous bioaugmentation (ABA) in phenanthrenecontaminated
Patagonian soil microcosms, maintained
under arid conditions, on phenanthrene elimination and soil
microbial community. The polycyclic aromatic hydrocarbon
(PAH)-degrading strain
Sphingobium
sp. 22B previously
isolated from the Patagonian soil and selected by its resistance
to drying conditions was used as inoculant. The
phenanthrene concentration, dehydrogenase activity and
denaturing gradient electrophoresis of 16S rRNA gene were
monitored during 230 days. The results showed that when
the microcosms were maintained at 20 % of soil waterholding
capacity (WHC), the phenanthrene biodegradation
was drastically inhibited and changes in the genetic diversity
of soil microbial community were not detected, and neither
the ABA nor the biostimulation managed to overcome the
inhibitory effects. When the moisture was slightly increased,
reached 25 % WHC, the ABA showed a significant initial
stimulatory effect on phenanthrene biodegradation, demonstrating
the potential ofABAinPAH bioremediation process
in semiarid Patagonia.
