J Environ Manage 2018 Jul 5;217:56-70. Epub 2018 Apr 5.
Innovative Green Product Synthesis and Renewable Environment Development Research Group, Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Viet Nam. Electronic address:
Journal of the Taiwan Institute of Chemical Engineers
A novel Cr(VI) tolerant bacterial strain AR6 was isolated from leather industrial effluent contaminated soil
sample sources and it was identified as Cellulosimicrobium funkei following 16S rDNA gene sequencing.
Effect of various physicochemical properties on Cr(VI) reducing ability of the strain was also studied. The
results showed that the C. funkei strain AR6 was tolerant to very high concentration of Cr(VI) (1200 μg/ml)
and capable of reducing Cr(VI), under a wide range of pH (6–8) and temperature (30–40°C) with an
optimum at 7.0 and 35 °C. Further, studies verified that the removal of Cr(VI) was mainly achieved by
a metabolism depending on the bioreduction process. The C. funkei strain AR6 reduces and accumulates
chromium both in and around the cells, with cell walls acting as the major binding sites for chromium.
Raman spectroscopy analysis further confirmed that the chromium immobilization by the cells was in the
Cr(III) state. Toxic nature of the reduced product was evaluated by toxicity study using zebrafish embryos
(Danio rerio) model. Interestingly, when embryo exposed Cr(VI) survival (22.19%) and hatching (26.71%)
rates were reduced significantly. However, Cr(VI) intoxicated embryos significantly increased the cardiac
function (132 ± 2.65 beat/min) at 60 hpf. Conversely, reduced product excreted less teratogenic effects on
zebrafish embryos. The present finding suggested that the transformation of Cr(VI) to Cr(III) by novel C.
funkei is considered as an effective, ecofriendly and attractive strategy for remediation of Cr(VI) polluted