TY - JOUR
T1 - The geomicrobiology of chromium (VI) pollution
T2 - Microbial diversity and its bioremediation potential
AU - Al-Battashi, Huda
AU - Joshi, Sanket J.
AU - Pracejus, Bernhard
AU - Al-Ansari, Aliya
N1 - Publisher Copyright:
© Al-Battashi et al.
PY - 2016
Y1 - 2016
N2 - The role and significance of microorganisms in environmental recycling activities marks geomicrobiology one of the essential branches within the environmental biotechnology field. Naturally occurring microbes also play geo-active roles in rocks,leading to biomineralization or biomobilization of minerals and metals. Heavy metals,such as chromium (Cr),are essential micronutrients at very low concentrations,but are very toxic at higher concentrations. Generally,heavy metals are leached to the environment through natural processes or anthropogenic activities such as industrial processes,leading to pollution with serious consequences. The presence of potentially toxic heavy metals,including Cr,in soils does not necessarily result in toxicity because not all forms of metals are toxic. Microbial interaction with Cr by different mechanisms leads to its oxidation or reduction,where its toxicity could be increased or decreased. Chromite contains both Cr(III) and Fe(II) and microbial utilization of Fe(II)- Fe(III) conversion or Cr (III) - Cr (VI) could lead to the break-down of this mineral. Therefore,the extraction of chromium from its mineral as Cr (III) form increases the possibility of its oxidation and conversion to the more toxic form (Cr (VI)),either biologically or geochemically. Cr (VI) is quite toxic to plants,animals and microbes,thus its levels in the environment need to be studied and controlled properly. Several bacterial and fungal isolates showed high tolerance and resistance to toxic Cr species and they also demonstrated transformation to less toxic form Cr (III),and precipitation. The current review highlights toxicity issues associated with Cr species and environmental friendly bioremediation mediated by microorganisms.
AB - The role and significance of microorganisms in environmental recycling activities marks geomicrobiology one of the essential branches within the environmental biotechnology field. Naturally occurring microbes also play geo-active roles in rocks,leading to biomineralization or biomobilization of minerals and metals. Heavy metals,such as chromium (Cr),are essential micronutrients at very low concentrations,but are very toxic at higher concentrations. Generally,heavy metals are leached to the environment through natural processes or anthropogenic activities such as industrial processes,leading to pollution with serious consequences. The presence of potentially toxic heavy metals,including Cr,in soils does not necessarily result in toxicity because not all forms of metals are toxic. Microbial interaction with Cr by different mechanisms leads to its oxidation or reduction,where its toxicity could be increased or decreased. Chromite contains both Cr(III) and Fe(II) and microbial utilization of Fe(II)- Fe(III) conversion or Cr (III) - Cr (VI) could lead to the break-down of this mineral. Therefore,the extraction of chromium from its mineral as Cr (III) form increases the possibility of its oxidation and conversion to the more toxic form (Cr (VI)),either biologically or geochemically. Cr (VI) is quite toxic to plants,animals and microbes,thus its levels in the environment need to be studied and controlled properly. Several bacterial and fungal isolates showed high tolerance and resistance to toxic Cr species and they also demonstrated transformation to less toxic form Cr (III),and precipitation. The current review highlights toxicity issues associated with Cr species and environmental friendly bioremediation mediated by microorganisms.
KW - Chromite
KW - Chromium (III)
KW - Chromium (VI) toxicity
KW - Microbial bioremediation
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U2 - 10.2174/1874070701610010379
DO - 10.2174/1874070701610010379
M3 - Article
AN - SCOPUS:84996526293
SN - 1874-0707
VL - 10
SP - 379
EP - 389
JO - Open Biotechnology Journal
JF - Open Biotechnology Journal
ER -