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8.1 Introduction
Microbial biosurfactants are amphiphilic molecules comprising hydrophilic polar
moiety which can be an oligo- or monosaccharide, protein, polysaccharide, or peptide, and unsaturated or saturated fatty alcohols form the hydrophobic moiety
(Rodrigues 2015). The main significant feature of surface active molecules is
hydrophilic- lipophilic equilibrium which imparts both hydrophilic and hydrophobic
nature to these compounds. Owing to the amphiphilic nature, biosurfactants are able
to raise the surface area of water insoluble compounds as well as modify the cell
surface properties of microorganisms. Biosurfactants serve as good foaming agents,
emulsifiers, and dispersing agents owing to their surfactant nature (De et al. 2015).
They are functionally dynamic at harsh conditions of high temperature, salt, and
pH. Various properties of biosurfactants including dispersion, emulsification, deemulsification, wetting, and foaming prove their effectiveness in remediation through
biological processes and removal of metal and organic contaminants (Wu and Lu
2015). Biosurfactants are able to complex with metals and carry out elimination of
heavy metals from surface soil layers in metal-contaminated sites (Sarma and Prasad
2015). Because of their surface active properties, they enhance the solubility of
hydrophobic particles like pesticides accumulated in soil and water (Neitsch
et al. 2016).
Bioremediation overcomes the conventional cleanup processes by emerging as
novel economical method to resolve various concerns related to environmental pollution. Biosurfactants are well known as desirable alternatives to synthetic surfactants in remediation of polluted areas and oil spill treatments (Mulligan 2005)
(Fig. 8.1). Biosurfactants enhance hydrocarbon degradation by increasing their
bioavailability due to emulsification of hydrocarbon-water mixtures. When compared to synthetic surfactants, microbial surfactants are less toxic as well as stable
and efficient in promoting bioremediation technology. Moreover, a variety of substrates including industrial wastes can be used for their production with simple
experimental methods (Muthusamy et al. 2008). This chapter comprehensively
discusses various environmental applications of biosurfactants in turn to provide
novel approaches for the advancement of efficient and ecofriendly alternatives for
the bioremediation of contaminated sites. It also discusses how the future research
needs to be addressed to make biosurfactant-based remediation strategies more
accessible.
K. V. Deepika et al.
8.1 Introduction
Microbial biosurfactants are amphiphilic molecules comprising hydrophilic polar
moiety which can be an oligo- or monosaccharide, protein, polysaccharide, or peptide, and unsaturated or saturated fatty alcohols form the hydrophobic moiety
(Rodrigues 2015). The main significant feature of surface active molecules is
hydrophilic- lipophilic equilibrium which imparts both hydrophilic and hydrophobic
nature to these compounds. Owing to the amphiphilic nature, biosurfactants are able
to raise the surface area of water insoluble compounds as well as modify the cell
surface properties of microorganisms. Biosurfactants serve as good foaming agents,
emulsifiers, and dispersing agents owing to their surfactant nature (De et al. 2015).
They are functionally dynamic at harsh conditions of high temperature, salt, and
pH. Various properties of biosurfactants including dispersion, emulsification, deemulsification, wetting, and foaming prove their effectiveness in remediation through
biological processes and removal of metal and organic contaminants (Wu and Lu
2015). Biosurfactants are able to complex with metals and carry out elimination of
heavy metals from surface soil layers in metal-contaminated sites (Sarma and Prasad
2015). Because of their surface active properties, they enhance the solubility of
hydrophobic particles like pesticides accumulated in soil and water (Neitsch
et al. 2016).
Bioremediation overcomes the conventional cleanup processes by emerging as
novel economical method to resolve various concerns related to environmental pollution. Biosurfactants are well known as desirable alternatives to synthetic surfactants in remediation of polluted areas and oil spill treatments (Mulligan 2005)
(Fig. 8.1). Biosurfactants enhance hydrocarbon degradation by increasing their
bioavailability due to emulsification of hydrocarbon-water mixtures. When compared to synthetic surfactants, microbial surfactants are less toxic as well as stable
and efficient in promoting bioremediation technology. Moreover, a variety of substrates including industrial wastes can be used for their production with simple
experimental methods (Muthusamy et al. 2008). This chapter comprehensively
discusses various environmental applications of biosurfactants in turn to provide
novel approaches for the advancement of efficient and ecofriendly alternatives for
the bioremediation of contaminated sites. It also discusses how the future research
needs to be addressed to make biosurfactant-based remediation strategies more
accessible.
K. V. Deepika et al.