Utilisation of Supernatants of Pure Cultures of Streptomyces thermocarboxydus NH50 to Reduce Chromium Toxicity and Mobility in Contaminated Soils

Abstract : Chromium is a heavy metal used in various industrial sectors. Improper handling and storage of chromium-laden effluents or wastes can lead to the pollution of the environment. The most toxic form is the more mobile one: hexavalent chromium Cr(VI). The reduction of Cr(VI) results in the immobilisation of chromium into its less toxic trivalent form Cr(III). This phenomenon may prevent the contamination of groundwater when the soil in the vadose zone is contaminated. Many bacteria have been isolated from contaminated soils and described to reduce Cr(VI) into Cr(III). A new Cr(VI)-reducing strain, identified as a Streptomyces thermocarboxydus,has been isolated and studied in our laboratories for its ability to reduce Cr(VI). This aerobic bacterium, in contrast to other genera described which mediate reduction via enzymes, produces reducing agents into the culture supernatants. Cr(VI) reduction by these substances is accelerated by the presence of small concentration of cupric ions (Cu2+). The reducing agent(s) can be easily recovered from the bacterial cultures and used as cell-free solution to treat contaminated soils by an in situ or ex situ processes.
Document type :
Journal articles
Complete list of metadatas

https://hal.archives-ouvertes.fr/hal-02043288
Contributor : Rémy Bayard <>
Submitted on : Wednesday, February 20, 2019 - 7:25:45 PM
Last modification on : Thursday, February 21, 2019 - 12:00:06 PM

Identifiers

  • HAL Id : hal-02043288, version 1

Collections

Citation

R. Bayard, Valérie Desjardin. Utilisation of Supernatants of Pure Cultures of Streptomyces thermocarboxydus NH50 to Reduce Chromium Toxicity and Mobility in Contaminated Soils. Water, Air, and Soil Pollution: Focus, Springer Verlag, 2003, 3 (3), pp.153-160. ⟨hal-02043288⟩

Share

Metrics

Record views

10