Utilização de altas concentrações de benzeno, tolueno e xileno (compostos BTX) como fonte de carbono por linhagens bacterianas
Abstract
BTX compouds [benzene, toluene and xylene isomers (ortho, meta
and para)] are light aromatics present in gasoline. They are toxic and
relatively soíuble in water. This high solubility in comparison with other
petroleum hydrocarbons explains their potential effect in the environment.
Experimenta with pre-conditionated cultures, isolated from petroleum
contaminated sites, were carried out with the aim of selecting sotventtolerant
strains able of growing in high concentrations of BTX. Those
strains were evaluated for their ability of p-xylene utilization. After 3 days
of incubation, two strains were responsible for high percentages of pxylene
removal from culture médium. It was concluded that these results
were related to biodegradation, since the strains were able to grow in pxylene
as the sole source of carbon and energy. High performance liquid
chromatography and gas chromatography with flame ionization detection
were used for BTX-determinationsr Biosurfactant production from the
cultures was also evaluated, by emulsifying activity and emulsifying index
(E24) determinations. Emulsification did not showany relationship with pxylene
biodegradation.