Hexavalent chromium removal in vitro and from industrial wastes, using chromate-resistant strains of filamentous fungi indigenous to contaminated wastes.
Two chromate-resistant filamentous fungi, strains H13 and Ed8, were selected from seven independent fungal isolates indigenous to Cr(VI)-contaminated soil because of their ability to decrease hexavalent chromium levels in the growth medium. Morphophysiological studies identified strain H13 as a Penicillium sp. isolate and Ed8 as an Aspergillus sp. isolate. When incubated in minimal medium with glucose as a carbon source and in the presence of 50 microg/mL Cr(VI), these strains caused complete disappearance of Cr(VI) in the growth medium after about 72 h of incubation. Total chromium concentration in growth medium was constant during culture growth, and no accumulation of chromium in fungal biomass was observed. Quantitative determinations of oxidized and reduced chromium species during the reduction process revealed stoichiometric conversion of Cr(VI) to Cr(III). A decrease in Cr(VI) levels from industrial wastes was also induced by Ed8 or H13 biomass. These results indicate that chromate-resistant filamentous fungi with Cr(VI)-reducing capability could be useful for the removal of Cr(VI) contamination.
Acevedo-Aguilar
Francisco Javier
FJ
Instituto de Investigaciones Científicas, Universidad de Guanajuato, México.
Espino-Saldaña
Angeles Edith
AE
Leon-Rodriguez
Ireri Lizzuli
IL
Rivera-Cano
Ma Elena
ME
Avila-Rodriguez
Mario
M
Wrobel
Kazimierz
K
Wrobel
Katarzyna
K
Lappe
Patricia
P
Ulloa
Miguel
M
Gutiérrez-Corona
J Felix
JF
D001230:Aspergillus / Q000187:drug effects / Q000378:metabolism; D018533:Biomass; D002840:Chromates / Q000378:metabolism* / Q000633:toxicity; D002857:Chromium / Q000378:metabolism*; D005658:Fungi / Q000187:drug effects / Q000378:metabolism*; D007220:Industrial Waste / Q000032:analysis / Q000517:prevention & control*; D010084:Oxidation-Reduction; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013997:Time Factors
D002840:Chromates; D007220:Industrial Waste; D012989:Soil Pollutants; D002857:Chromium; C074702:chromium hexavalent ion