01925nas a2200205   4500008004100000022001400041245007200055210006900127260007300196300001200269490000800281520119200289653001701481653002301498653002401521653002501545100002401570700002501594856010001619       2009                        eng d  a0304-389400aStudies on biological reduction of chromate by Streptomyces griseus0 aStudies on biological reduction of chromate by Streptomyces gris  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP  a539-5450 v1693 a<p>Chromium is a toxic heavy metal used in various industries and leads to environmental pollution due to improper handling. The most toxic form of chromium Cr(VI) can be converted to less toxic Cr(III) by reduction. Among the actinomycetes tested for chromate reduction, thirteen strains reduced Cr(VI) to Cr(III), of which one strain of Streptomyces griseus (NCIM 2020) was most efficient showing complete reduction within 24h. The organism was able to use a number of carbon sources as electron donors. Sulphate, nitrate, chloride and carbonate had no effect on chromate reduction during growth while cations such as Cd, Ni, Co and Cu were inhibitory to varying degrees. Chromate reduction was associated with the bacterial cells and sonication was the best method of cell breakage to release the enzyme. The enzyme was constitutive and did not require presence of chromate during growth for expression of activity. Chromate reduction with cell free extract (CFE) was observed without added NADH. However, addition of NAD(P)H resulted in 2-3-fold increase in activity. Chromate reductase showed optimum activity at 28 degrees C and pH 7 (C) 2009 Elsevier B.V. All rights reserved.</p>10aBioreduction10aChromate reductase10aHexavalent chromium10aStreptomyces griseus1 aPoopal, Ashwini, C.1 aLaxman, Ryali, Seeta  uhttps://library.ncl.res.in/content/studies-biological-reduction-chromate-streptomyces-griseus-0