title: Production of bioemulsifiers by Amycolatopsis tucumanensis DSM 45259 and their potential application in remediation technologies for soils contaminated with hexavalent chromium.
abstract: In recent years, increasing interest has been shown in the use of bioemulsifiers as washing agents that can enhance desorption of soil-bound metals. However, high production costs derived from the use of expensive substrates for formulation of the fermentation media represent the main challenge for full, large-scale implementation of bioemulsifiers. This work reports on a first study of bioemulsifier production by the actinobacterium Amycolatopsis tucumanensis DSM 45259 using different carbon and nitrogen sources. Preliminary results on the potential use of these compounds as washing agents for soils contaminated with Cu(II) and Cr(VI) are also presented. The best specific production was detected using glycerol and urea as carbon and nitrogen substrates, respectively. However, with all of the substrates used during the batch assay, the bioemulsifiers showed high levels of stability at extreme conditions of pH, temperature, and salt concentration. Under the current assay conditions, the bioemulsifiers were not effective in removing Cu(II) from soil. However, they were able to mediate Cr(VI) recovery, with the removal percentage doubled compared to that seen when using deionized water. These findings appear promising for the development of remediation technologies for hexavalent chromium compounds based upon direct use of these microbial emulsifiers.
authors.affiliation: Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CONICET, Av. Belgrano y Pje. Caseros, 4000 Tucumán, Argentina; Universidad de San Pablo-Tucumán, Argentina. Electronic address: veronicacollin@yahoo.com.ar.
authors.forename: Verónica Leticia
authors.initials: VL
authors.lastname: Colin
authors.forename: María Fernanda
authors.initials: MF
authors.lastname: Castro
authors.forename: María Julia
authors.initials: MJ
authors.lastname: Amoroso
authors.forename: Liliana Beatriz
authors.initials: LB
authors.lastname: Villegas
mesh_terms: D000192:Actinomycetales / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D001216:Asparagine / Q000494:pharmacology; D002857:Chromium / Q000737:chemistry*; D045703:Emulsifying Agents / Q000737:chemistry* / Q000378:metabolism*; D052918:Environmental Restoration and Remediation / Q000379:methods; D005947:Glucose / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D012989:Soil Pollutants / Q000737:chemistry*; D014508:Urea / Q000494:pharmacology
chemical_list: D045703:Emulsifying Agents; D012989:Soil Pollutants; D002857:Chromium; C074702:chromium hexavalent ion; D001216:Asparagine; D014508:Urea; D005947:Glucose; D005990:Glycerol
keywords: Actinobacterium; Bioemulsifiers; Heavy metals; Soil washing