INVESTIGADORES
MARTORELL Maria Martha
congresos y reuniones científicas
Título:
Hexavalente chromium: culture conditions affecting biological remediation
Autor/es:
FERNANDEZ, PABLO M.; MARTORELL, MARIA M.; SINERIZ, FAUSTINO; FARINA, JULIA I.; FIGUEROA, LUCIA I. C.
Lugar:
Toronto, ON Canadá
Reunión:
Congreso; SIM SOCIETY FOR INDUSTRIAL MICROBIOLOGY 2009 ANNUAL MEETING & EXHIBITION; 2009
Institución organizadora:
SIM, Society for Industrial Microbilogy
Resumen:
Contamination by
chromium compounds is caused by a variety of industrial applications eventually
leading to heavy pollution of soil, surface water and atmosphere.Two chromium
resistant yeast strains (P. jadinii and P. anomala) converting toxic Cr(VI) to the
less toxic and immobile Cr(III), were considered to evaluate different culture
conditions in order to optimize the best removal performance.Assays were
carried out in YNB (w/o AA and ammonium sulfate) medium supplemented with
sucrose as C-source and ammonium sulfate as N-source during 120 h. The
influence of Cr(VI) initial concentration, temperature and agitation conditions
on Cr(VI) removal were evaluated. Culture broth samples were analyzed for pH,
biomass dry weight (BDW), glucose and ammonium following conventional
protocols; Cr(VI) was measured by the diphenylcarbazide (DPC) method.Despite
the inhibitory effects of Cr(VI) on the yeasts growth, Cr(VI) reducing capacity
did not appear to be disturbed. For both yeast strains biomass production and
Cr(VI) removal performance was positively affected by increasing incubation
temperature (up to 30ºC)
and under shaken culture conditions (up to 250 rpm). The time needed for
complete Cr(VI) disappearance increased with the increment of initial Cr(VI)
concentration. For P jadinii and P. anomala, at low initial chromate
concentration (0.5 mM),
strains were able to completely remove Cr(VI) within 12 and 8 h of incubation,
respectively. While at 2 mM,
full removal required 96 and 72 h, respectively. Optimization of these
parameters constitutes an important contribution in order to perform a
succesful Cr-removal for bioremediation purposes.