Effet des polyamines sur la réduction du chrome hexavalent par des souches bactériennes et leur résistance

Effect of polyamines on the reduction of hexavalent chromium by bacterial strains and their resistance. Polyamines are involved in several functions in bacteria. In this study, we examined the role of polyamines in hexavalent chromium (Cr[VI]) reduction by three bacterial strains isolated from sites contaminated by tannery effluents. The strains were identified as Serratia proteamaculans, Leucobacter chromiireducens and Brevibacterium frigoritolerans. The inhibition of polyamine synthesis by α-difluoromethylornithine (DFMO) caused a decrease in Cr(VI) tolerance in the bacterial isolates, indicating the role of endogenous polyamines in resistance to Cr(VI). The exogenous application of polyamines (putrescine, spermidine, cadaverine) was found to stimulate growth and Cr(VI) reduction by the bacterial strains in Luria-Bertani medium. The results show the importance of polyamines in response to heavy metal stresses, especially Cr(VI) toxicity