Intracellular chromium accumulation by Streptomyces sp. MC1

Abstract

Streptomyces sp. MC1, previously isolated from sugar cane, has shown ability to reduce Cr(VI) in liquid minimal medium and soil samples. The objective of this work was to demonstrate the intracellular chromium accumulation by Streptomyces sp. MC1 under different culture conditions. This strain was able to accumulate up to 3.54 mg of Cr (III) per gram of wet biomass, reducing the 98% of Cr (VI) and removing 13.9% of chromium from the culture medium supernatants. Streptomyces sp. MC1 chromium bioaccumulation ability was corroborated by using Timm's reagent technique, a low-cost method, which has been used by first time to detect chromium deposits in bacteria. The results of atomic absorption spectrometry, scanning electron microscopy, and energy dispersive X-ray analysis suggest that the mechanism of Cr(VI) resistance observed in Streptomyces sp. MC1 includes adsorption coupled with reduction to Cr(III), and finally, Cr(III) bioaccumulation. This mechanism have special relevance to remediation of Cr(VI) contaminated environments by Streptomyces sp. MC1.

Role of Actinobacteria in Bioremediation

“…MC1 could include adsorption coupled with reduction to Cr(III) and, finally, Cr(III) bioaccumulation (Polti et al, 2011a). MC1 to accumulate Cr(III) after the Cr(VI) reduction was also reported.…”

Simultaneous chromate and sulfate removal by Streptomyces sp. MC1. Changes in intracellular protein profile induced by Cr(VI)

“…MC1 was able to accumulate up to 15% of total chromium after 70 days of incubation. As Cr(VI) was no detected intracellularly, the authors assumed that chromium in the cell corresponded to Cr(III) . In the present work, 50% of total chromium was removed from medium culture after 2 days of incubation when the medium was supplemented with sulfate.…”

Potential application of a bioemulsifier-producing actinobacterium for treatment of vinasse

“…In this connection, our research group has reported on significant advances regarding the Cr(VI)-removal mechanisms operating in Streptomyces sp. MC1 (Polti et al, 2007(Polti et al, , 2009(Polti et al, , 2010(Polti et al, , 2011a(Polti et al, , 2011b(Polti et al, , 2014. However, results presented herein are the first advances on this strain's potential for removing Mn, Fe, Zn, As, and Pb.…”