Economical fermentation media for the production of a whole cell catalyst for the treatment of Cr(VI)-containing wastewaters

MAURICIO J. ALESSANDRELLO; DIANA L. VULLO; DIANA L. VULLO; MAURICIO J. ALESSANDRELLO

REVISTA ARGENTINA DE MICROBIOLOGíA

ASOCIACION ARGENTINA MICROBIOLOGIA

Lugar: Buenos Aires; Año: 2016 vol. 48 p. 245 - 251

0325-7541

The biotechnology sector is continually seeking sustainable and more economical bioprocesses. Fermentation media produced with cheap components or wastes reduce the production costs and, if wastes are used, they contribute to avoid environmental pollution. In this work, microbial growth media based in molasses or acidified glycerol as carbon sources and fertilizer as nitrogen source were tested for the production of a whole cell catalyst that could be used in Cr(VI)-containing wastewater treatments. Results showed that the highest biomass production yield was obtained with a medium containing acidified glycerol 5 % v/v and fertilizer 0.6 % v/v. Using this medium, biomass was produced, immobilized in calcium alginate beads and used as catalyst in the transformation of Cr(VI) to Cr(III). The catalyst could be efficiently used for 5 reduction cycles of 40 mg/l Cr(VI) each. Cr(III) retention assays were done to determine if the Cr(III) could be retained by the catalyst avoiding its solubilisation in the supernatants. The retention capacity of the catalyst at 32 ºC and pH 3.0 was 3 mg Cr(III)/g. Both alternative and economic fermentation medium and Cr(VI)-containing wastewater treatment are proposed.