The enhanced effect of key microorganisms in chromium contaminated soil in Cr(VI) reduction

• Four strains with high Cr(VI) tolerance capable of reducing Cr(VI) were isolated. • In-situ soil particles and soil key microflora can synergistically remove Cr(VI). Ochrobactrum sp. and Paenarthrobacter sp. are the key microorganisms. • The synergistic mechanism between in-situ soil particles and soil flora was revealed.