bioremediation of Cd has been investigated by many researchers. Stationary cells of
Bacillus thuringiensis exhibited high potential for Cd binding (El-Helow et al.
2000), while Ralstonia sp. showed high affinity for the removal of Cd
+2
(Chompoothawat et al. 2010). Cupriavidus taiwanensis KKU2500-3 was isolated
from cadmium-contaminated soil and found to be producing more thi-containing
protein. It also decreases the accumulation of Cd in rice plant by 61%
(Siripornadulsil and Siripornadulsil 2013). Pseudomonas sp. M3 (strain RZCD1)
was found to be resistant against cadmium and useful for bioremediation of
cadmium-contaminated industrial wastewater (Abbas et al. 2014). Priyalaxmi et al.
(2014) reported that mangrove ecosystem contains a wide microbial diversity that is
helpful in the biosorption and reduction of cadmium. Escherichia coli, Salmonella
typhi, Bacillus licheniformis, and Pseudomonas fluorescens isolated showed promising results for the bioremediation of heavy metals including Cd from the textile dye
effluents. Flavobacterium psychrophilum and Flavobacterium sp. ARSA-103 are
hexavalent Cr- and Cd (II)-resistant bacteria collected from tannery effluents
which were used to remove metal-contaminated effluents. Flavobacterium
psychrophilum is a fish pathogen which is resistant to heavy metals and can grow
efficiently in the heavy metal stressed environment. Therefore it can be used to
remediate heavy metals so as to make the environment heavy metal pollution-free
(Mukherjee et al. 2015). From activated sludge many different species of bacteria
have been isolated that produce metabolic products called extracellular polymeric
substances (EPS) which help in heavy metal removal by formation of complexes
between carboxyl, hydroxyl, and phenolic surface functional groups of the extracellular polymeric substances and heavy metals (Yuncu et al. 2006). Biosorption of
metal by bacteria is dependent on external factors such as pH, other ions in bulk
solutions (which may be in competition), organic material in bulk solution, and
temperature (Comte et al. 2008).
5.1.2 Bioremediation of Cadmium Using Fungi
Fungi show a great affinity toward metal ions as compared to other microorganisms.
They can accumulate heavy metals by means of physicochemical and biological
mechanisms from their external environment (Cabuk et al. 2005; Preetha and
Viruthagiri 2005) (as shown in Fig. 15.4). Fungi have the capacity to bind with
cadmium by the help of cysteine-rich protein called metalloprotein (Margoshes and
Vallee 1957). Aspergillus fumigatus fungal isolate has good biosorption capacity
toward removal of selected heavy metals from contaminated sites (Iram et al. 2013).
Aspergillus fumigatus was isolated from the polluted soil, and its biosorption
capacity against heavy metals, viz., Pb, Cd, Cr, Cu, Zn, and Ni, was checked.
Maximum biosorption rate (76.07%) at 800ppm was exhibited by fungal isolate
K3 of Aspergillus fumigatus and showed higher accumulation of metal lead (Shazia
et al. 2013). Removal of Cd from wastewater by Aspergillus fumigatus was tested at
different pH, inoculum sizes, and incubation times. It could remove 76% of Cd with
15 Cadmium as an Environmental Pollutant: Ecotoxicological Effects, Health. . .
371
Bacillus thuringiensis exhibited high potential for Cd binding (El-Helow et al.
2000), while Ralstonia sp. showed high affinity for the removal of Cd
+2
(Chompoothawat et al. 2010). Cupriavidus taiwanensis KKU2500-3 was isolated
from cadmium-contaminated soil and found to be producing more thi-containing
protein. It also decreases the accumulation of Cd in rice plant by 61%
(Siripornadulsil and Siripornadulsil 2013). Pseudomonas sp. M3 (strain RZCD1)
was found to be resistant against cadmium and useful for bioremediation of
cadmium-contaminated industrial wastewater (Abbas et al. 2014). Priyalaxmi et al.
(2014) reported that mangrove ecosystem contains a wide microbial diversity that is
helpful in the biosorption and reduction of cadmium. Escherichia coli, Salmonella
typhi, Bacillus licheniformis, and Pseudomonas fluorescens isolated showed promising results for the bioremediation of heavy metals including Cd from the textile dye
effluents. Flavobacterium psychrophilum and Flavobacterium sp. ARSA-103 are
hexavalent Cr- and Cd (II)-resistant bacteria collected from tannery effluents
which were used to remove metal-contaminated effluents. Flavobacterium
psychrophilum is a fish pathogen which is resistant to heavy metals and can grow
efficiently in the heavy metal stressed environment. Therefore it can be used to
remediate heavy metals so as to make the environment heavy metal pollution-free
(Mukherjee et al. 2015). From activated sludge many different species of bacteria
have been isolated that produce metabolic products called extracellular polymeric
substances (EPS) which help in heavy metal removal by formation of complexes
between carboxyl, hydroxyl, and phenolic surface functional groups of the extracellular polymeric substances and heavy metals (Yuncu et al. 2006). Biosorption of
metal by bacteria is dependent on external factors such as pH, other ions in bulk
solutions (which may be in competition), organic material in bulk solution, and
temperature (Comte et al. 2008).
5.1.2 Bioremediation of Cadmium Using Fungi
Fungi show a great affinity toward metal ions as compared to other microorganisms.
They can accumulate heavy metals by means of physicochemical and biological
mechanisms from their external environment (Cabuk et al. 2005; Preetha and
Viruthagiri 2005) (as shown in Fig. 15.4). Fungi have the capacity to bind with
cadmium by the help of cysteine-rich protein called metalloprotein (Margoshes and
Vallee 1957). Aspergillus fumigatus fungal isolate has good biosorption capacity
toward removal of selected heavy metals from contaminated sites (Iram et al. 2013).
Aspergillus fumigatus was isolated from the polluted soil, and its biosorption
capacity against heavy metals, viz., Pb, Cd, Cr, Cu, Zn, and Ni, was checked.
Maximum biosorption rate (76.07%) at 800ppm was exhibited by fungal isolate
K3 of Aspergillus fumigatus and showed higher accumulation of metal lead (Shazia
et al. 2013). Removal of Cd from wastewater by Aspergillus fumigatus was tested at
different pH, inoculum sizes, and incubation times. It could remove 76% of Cd with
15 Cadmium as an Environmental Pollutant: Ecotoxicological Effects, Health. . .
371