responsible for biosorption are called biosorbents. Biosorption of metals by the
use of microbes is controlled by the parameters such as the nature of biosorbent
undergoing the process, age of microbial culture and biomass from where it is
originated, the nature of interactions that occur between metals with functional
groups which are native to the cell wall of biomass, concentration of biosorbent
present during the reaction, properties of metals to be removed and their
concentrations present in solution and other factors: pH, temperature and the
presence of other cations present during the whole process (Sen and Chakrabarti
2009). Bacteria are magnificent biosorbents because of the presence of their
more surface-to-volume ratio along with a favourable number of chemosorption
sites that are active, e.g. cell wall teichoic acid of bacteria (Banik et al. 2014).
15.4 Microbes Involved in Bioremediation
Microorganisms play a paramount role not only in controlling the biogeochemical
cycles, for maintaining ecological balance, but also in maintaining a healthy environment for us, combating the plant diseases, and play a significant part in cleaning
of atmospheric contaminants from the atmosphere (Malla et al. 2018). Microbes are
the only organisms present in the environment which have the capability of exploitation of organic/inorganic compounds from the surrounding environment for their
growth through many processes, for example, binding, oxidation, volatilization, and
immobilization (Kulkarni and Chaudhari 2007; Malla et al. 2018). Microbes are
empowered to inhabit different ecological niches where they can process extraordinary metabolic and physiological activities (Kulkarni and Chaudhari 2007).
Microorganisms present in the environment such as bacteria, fungi, actinomycetes,
protozoa, and algae carry out the process of recycling of organic compounds from
where the new plant life can be raised and helps to transform organic waste (Fan and
Krishnamurthy 1995). The microbes can be indigenous, i.e. belong to a particular
contaminated space or can be isolated from anywhere else and then exposed to the
contaminated sites (Shah 2014). Microorganisms are nature’s recyclers because they
have a vital metabolic potential for transformation of natural and synthetic
compounds into energy sources and organic materials for their growth and to
produce energy for their movement and respiration; therefore, they are considered
as infallible (Fan and Krishnamurthy 1995; Rieger et al. 2002; Sasikumar and
Papinazath 2003). Microbes break down organic chemicals into CO 2 , H 2 O and
CH 4 (Ateia et al. 2016; Nandal et al. 2015). Microbes can substitute chemical or
physical biodegradation processes by biological processes into a cheap and environmentally friendly way. Therefore, it is a promising, new environmental biotechnological technique as they can quickly respond and adapt to changes in the
surrounding conditions (Sasikumar and Papinazath 2003; de Mora et al. 2005).
Parameters such as pH, temperature, nutrient levels and aeration are essential to
facilitate the metabolism of microbial cells for the biotransformation process carried
out by them. When a microbe comes into proximity of complex organic matter,
extracellular enzymes are liberated that helps in the remediation of materials with
15 The Role of Microorganisms in Remediation of Environmental Contaminants
431
use of microbes is controlled by the parameters such as the nature of biosorbent
undergoing the process, age of microbial culture and biomass from where it is
originated, the nature of interactions that occur between metals with functional
groups which are native to the cell wall of biomass, concentration of biosorbent
present during the reaction, properties of metals to be removed and their
concentrations present in solution and other factors: pH, temperature and the
presence of other cations present during the whole process (Sen and Chakrabarti
2009). Bacteria are magnificent biosorbents because of the presence of their
more surface-to-volume ratio along with a favourable number of chemosorption
sites that are active, e.g. cell wall teichoic acid of bacteria (Banik et al. 2014).
15.4 Microbes Involved in Bioremediation
Microorganisms play a paramount role not only in controlling the biogeochemical
cycles, for maintaining ecological balance, but also in maintaining a healthy environment for us, combating the plant diseases, and play a significant part in cleaning
of atmospheric contaminants from the atmosphere (Malla et al. 2018). Microbes are
the only organisms present in the environment which have the capability of exploitation of organic/inorganic compounds from the surrounding environment for their
growth through many processes, for example, binding, oxidation, volatilization, and
immobilization (Kulkarni and Chaudhari 2007; Malla et al. 2018). Microbes are
empowered to inhabit different ecological niches where they can process extraordinary metabolic and physiological activities (Kulkarni and Chaudhari 2007).
Microorganisms present in the environment such as bacteria, fungi, actinomycetes,
protozoa, and algae carry out the process of recycling of organic compounds from
where the new plant life can be raised and helps to transform organic waste (Fan and
Krishnamurthy 1995). The microbes can be indigenous, i.e. belong to a particular
contaminated space or can be isolated from anywhere else and then exposed to the
contaminated sites (Shah 2014). Microorganisms are nature’s recyclers because they
have a vital metabolic potential for transformation of natural and synthetic
compounds into energy sources and organic materials for their growth and to
produce energy for their movement and respiration; therefore, they are considered
as infallible (Fan and Krishnamurthy 1995; Rieger et al. 2002; Sasikumar and
Papinazath 2003). Microbes break down organic chemicals into CO 2 , H 2 O and
CH 4 (Ateia et al. 2016; Nandal et al. 2015). Microbes can substitute chemical or
physical biodegradation processes by biological processes into a cheap and environmentally friendly way. Therefore, it is a promising, new environmental biotechnological technique as they can quickly respond and adapt to changes in the
surrounding conditions (Sasikumar and Papinazath 2003; de Mora et al. 2005).
Parameters such as pH, temperature, nutrient levels and aeration are essential to
facilitate the metabolism of microbial cells for the biotransformation process carried
out by them. When a microbe comes into proximity of complex organic matter,
extracellular enzymes are liberated that helps in the remediation of materials with
15 The Role of Microorganisms in Remediation of Environmental Contaminants
431