title: Chromate reduction by PVA-alginate immobilized Streptomyces griseus in a bioreactor.
abstract: Microbial reduction of toxic Cr6+ to the less toxic Cr3+ is potentially a useful bioremediation process. Among the matrices tested for whole cell immobilization of an efficient chromate-reducing Streptomyces griseus strain, PVA-alginate was the most effective and was used for reduction of Cr(VI) in a bioreactor. Cr6+ reduction efficiency decreased as Cr6+ was increased from 2 to 12 mg l(-1) but increased with an increase in biomass concentration. However, increasing the flow rate from 2 to 8 ml h(-1) did not significantly affect Cr(6+) reduction. The reduction was faster in simulated effluent than in synthetic medium and complete removal of 8 mg Cr6+ l(-1) from effluent and synthetic medium occurred in 2 and 12 h, respectively. Our results indicate that immobilized S. griseus cells could be applied for the large-scale bioremediation of chromate-containing effluents and wastewaters.
authors.affiliation: Division of Biochemical Sciences, National Chemical Laboratory, Pune 411008, India.
authors.forename: Ashwini C
authors.initials: AC
authors.lastname: Poopal
authors.forename: R Seeta
authors.initials: RS
authors.lastname: Laxman
mesh_terms: D000464:Alginates / Q000378:metabolism*; D018533:Biomass; D019149:Bioreactors; D018914:Cells, Immobilized; D002840:Chromates / Q000378:metabolism*; D002857:Chromium / Q000032:analysis; D003470:Culture Media; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D010084:Oxidation-Reduction; D011142:Polyvinyl Alcohol / Q000378:metabolism*; D012212:Rheology; D013305:Streptomyces griseus / Q000166:cytology* / Q000378:metabolism*; D014865:Waste Disposal, Fluid
chemical_list: D000464:Alginates; D002840:Chromates; D003470:Culture Media; D006603:Hexuronic Acids; D002857:Chromium; C074702:chromium hexavalent ion; D020723:Glucuronic Acid; D011142:Polyvinyl Alcohol