root anatomy would produce rice plants with increased root porosity and a high rate
of ROL. It is also necessary to investigate how rice and other plant species metabolize As; thus, new endogenous and exogenous genes become available for the
mitigation of As accumulation in rice grains (Kumarathilaka et al. 2019).
7 Bioremediation
Removal of arsenic from its contaminated soil incurs numerous methods under
bioremediation. Bioremediation is the process of using microorganisms especially
bacteria to degrade/remediate the arsenic contamination by means of its metabolic
process particular its pathways (Das and Sarkar 2018; Hlihor et al. 2017). Different
bacteria have been reported regarding the degradation of heavy metals, e.g., As, zinc
(Zn), lead (Pb), and selenium (Se). Many studies reported about the about microorganisms’ survival mechanism in the existence of As and its detoxification process by
intracellular bioaccumulation, involving redox and methylation reactions. Both
aerobic and anaerobic degradation pathways have been implicated for their existence
with As. For degrading As contaminants, bioremediation process will introduce a
higher number of chemoautotrophic bacteria (either aerobic or anaerobic (Alka et al.
2020). While As III passes through the aquaglyceroporin (GLpF) across the cell
membrane, few As-resistant bacteria gain energy during detoxification, oxidation, or
reduction of As, methylation of As V and As III, or demethylation of organic Asals,
which use phosphate transporters to facilitate the uptake of As V. Different bacterial
isolates are capable of solubilizing As through adsorption, organic ligand production, practice compartmentalization, biosorption, and mineral weathering caused by
microbes.
7.1 Phytoremediation
Phytoremediation process is involved in the following mechanism:
phytostabilization, phytoextraction, phytovolatilization, and phytofiltration
(Fig. 12.3). Phytoextraction involves the absorption and movement of contaminants
from the soil to the different parts of the plants through the root. Plants can absorb
metal in huge amounts; that is, few of the plants did not show any toxicity symptoms.
Some of the plants can absorb only very less toxic accumulation, which will not
express any toxic symptoms (Alka et al. 2020). Microbes and plants are used in
combination to reduce or remove the heavy metal toxicity which is known as
phytobial remediation. Microorganisms play a vital role in biogeochemical process,
they can form communities, and it will help the growth process of the plant and can
reduce/remove the toxic heavy metal. In addition to above functions, it also plays an
important role in forming mutual relationship in mangrove vegetation and occupies
248
P. Narayanasamy and R. K. Subramanian
of ROL. It is also necessary to investigate how rice and other plant species metabolize As; thus, new endogenous and exogenous genes become available for the
mitigation of As accumulation in rice grains (Kumarathilaka et al. 2019).
7 Bioremediation
Removal of arsenic from its contaminated soil incurs numerous methods under
bioremediation. Bioremediation is the process of using microorganisms especially
bacteria to degrade/remediate the arsenic contamination by means of its metabolic
process particular its pathways (Das and Sarkar 2018; Hlihor et al. 2017). Different
bacteria have been reported regarding the degradation of heavy metals, e.g., As, zinc
(Zn), lead (Pb), and selenium (Se). Many studies reported about the about microorganisms’ survival mechanism in the existence of As and its detoxification process by
intracellular bioaccumulation, involving redox and methylation reactions. Both
aerobic and anaerobic degradation pathways have been implicated for their existence
with As. For degrading As contaminants, bioremediation process will introduce a
higher number of chemoautotrophic bacteria (either aerobic or anaerobic (Alka et al.
2020). While As III passes through the aquaglyceroporin (GLpF) across the cell
membrane, few As-resistant bacteria gain energy during detoxification, oxidation, or
reduction of As, methylation of As V and As III, or demethylation of organic Asals,
which use phosphate transporters to facilitate the uptake of As V. Different bacterial
isolates are capable of solubilizing As through adsorption, organic ligand production, practice compartmentalization, biosorption, and mineral weathering caused by
microbes.
7.1 Phytoremediation
Phytoremediation process is involved in the following mechanism:
phytostabilization, phytoextraction, phytovolatilization, and phytofiltration
(Fig. 12.3). Phytoextraction involves the absorption and movement of contaminants
from the soil to the different parts of the plants through the root. Plants can absorb
metal in huge amounts; that is, few of the plants did not show any toxicity symptoms.
Some of the plants can absorb only very less toxic accumulation, which will not
express any toxic symptoms (Alka et al. 2020). Microbes and plants are used in
combination to reduce or remove the heavy metal toxicity which is known as
phytobial remediation. Microorganisms play a vital role in biogeochemical process,
they can form communities, and it will help the growth process of the plant and can
reduce/remove the toxic heavy metal. In addition to above functions, it also plays an
important role in forming mutual relationship in mangrove vegetation and occupies
248
P. Narayanasamy and R. K. Subramanian