PROIMI   05436
PLANTA PILOTO DE PROCESOS INDUSTRIALES MICROBIOLOGICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Chromium hexavalent: culture conditions affecting biological remediation
Autor/es:
FERNÁNDEZ, PABLO M.; MARTORELL, MARÍA M.; SIÑERIZ, FAUSTINO; FARIÑA, JULIA I.; FIGUEROA, LUCÍA I. C.
Lugar:
Toronto, ON Canada
Reunión:
Congreso; SOCIETY FOR INDUSTRIAL MICROBIOLOGY (SIM) 2009 ANNUAL MEETING & EXHIBITION; 2009
Institución organizadora:
SOCIETY FOR INDUSTRIAL MICROBIOLOGY
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.