Biochemical and molecular mechanisms involved in simultaneous phenol and Cr(VI) removal by Acinetobacter guillouiae SFC 500-1A

ONTAÑON O.M; GONZALEZ P; AGOSTINI E

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2015 vol. 22 p. 13014 - 13023

0944-1344

Bioremediation has emerged as anenvironmental friendly strategy to deal with environmental pollution. Since themajority of polluted sites contain complex mixtures of inorganic and organicpollutants, it is important to find bacterial strains that can cope withmultiple contaminants. In this work, a bacterial strain isolated from tannerysediments was identified as Acinetobacter guillouiae SFC 500-1A. This strain was able to simultaneously remove highphenol and Cr(VI) concentrations, and the mechanisms involved in such processwere evaluated. The phenol biodegradation was catalized by a phenol-inducedcatechol 1,2-dioxygenase through an ortho-cleavage pathway.Also, NADH-dependent chromate reductase activity was measured in the cytosolic fraction.The ability of this strain to reduce Cr(VI) to Cr(III) was corroborated bydetection of Cr(III) in cellular biomass after the removal process. Whilephenol did not affect significantly the chromate reductase activity, Cr(VI) wasa major disruptor of catechol dioxygenase activity. Nevertheless, this activitywas high even in presence of high Cr(VI) concentrations.  Our results suggest the potential applicationof A. guillouiae SFC 500-1A for wastewaters treatment, and theobtained data provide the insights into the removal mechanisms, dynamics, andpossible limitations of the bioremediation.