title: Acetate biostimulation as an effective treatment for cleaning up alkaline soil highly contaminated with Cr(VI).
abstract: Stimulation of microbial reduction of Cr(VI) to the less toxic and less soluble Cr(III) through electron donor addition has been regarded as a promising approach for the remediation of chromium-contaminated soil and groundwater sites. However, each site presents different challenges; local physicochemical characteristics and indigenous microbial communities influence the effectiveness of the biostimulation processes. Here, we show microcosm assays stimulation of microbial reduction of Cr(VI) in highly alkaline and saline soil samples from a long-term contaminated site in Guanajuato, Mexico. Acetate was effective promoting anaerobic microbial reduction of 15 mM of Cr(VI) in 25 days accompanied by an increase in pH from 9 to 10. Our analyses showed the presence of Halomonas, Herbaspirillum, Nesterenkonia/Arthrobacter, and Bacillus species in the soil sample collected. Moreover, from biostimulated soil samples, it was possible to isolate Halomonas spp. strains able to grow at 32 mM of Cr(VI). Additionally, we found that polluted groundwater has bacterial species different to those found in soil samples with the ability to resist and reduce chromate using acetate and yeast extract as electron donors.
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001. Col. Chamilpa, 62210, Cuernavaca, Morelos, Mexico.
authors.forename: Paloma
authors.initials: P
authors.lastname: Lara
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001. Col. Chamilpa, 62210, Cuernavaca, Morelos, Mexico.|Instituto Nacional de Medicina Genómica, Periférico Sur No. 4809, Col. Arenal Tepepan, Delegación Tlalpan, 14610, México, Distrito Federal, Mexico.
authors.forename: Enrique
authors.initials: E
authors.lastname: Morett
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001. Col. Chamilpa, 62210, Cuernavaca, Morelos, Mexico. katy@ibt.unam.mx.
authors.forename: Katy
authors.initials: K
authors.lastname: Juárez
mesh_terms: D019342:Acetic Acid / Q000008:administration & dosage / Q000378:metabolism*; D000693:Anaerobiosis; D001419:Bacteria / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002857:Chromium / Q000378:metabolism*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D060587:Groundwater / Q000382:microbiology; D008800:Mexico; D010084:Oxidation-Reduction; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D064091:Waste Disposal Facilities
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002857:Chromium; C074702:chromium hexavalent ion; D019342:Acetic Acid
keywords: Biostimulation; Chromate; Soil and groundwater pollution