236
I. A. Adelere and A. Lateef
health, and others (Caporgno and Mathys 2018; Charles et al. 2019; Koyande et al.
2019; Fields et al. 2020). Microalgae are more important as live feed in aquaculture (Walker and Berlinsky 2011). They are used to feed culture larvae, juvenile
shell, finfish and also for raising the zooplankton required for feeding of juvenile
animals (Taelman et al. 2013). The commonly used microalgae in aquaculture are
species of Chlorella, Tetraselmis, Isochrysis, Pavlova, Phaeodactylum, Chaetoceros,
Nannochloropsis, Skeletonema, and Thalassiosira (Roy and Pal 2015).
The use of biofertilizer is both economical and environment friendly. Members
of cyanobacteria are rich sources of biologically active constituents that can be used
as biofertilizers (Garcia-Gonzalez and Sommerfeld 2016). Cyanobacteria play an
important role in fixing atmospheric nitrogen with the aid of their heterocysts. They
produce complex organic carbon compounds that can bind to soil particles to improve
its quality such as soil structure, soil permeability, and water-holding capacity of
soil (Nisha et al. 2007). Phycoremediation is the process of using microalgae for the
removal or biotransformation of organic pollutants from environments with concomitant biomass propagation (Renuka et al. 2015). The potential of microalgae in metal
biosorption process has been studied extensively due to their ubiquitous occurrence
in nature. Many algal genera are known to have abilities to accumulate heavy metals,
thereby reducing their toxic effects in the environments (Jais et al. 2017). There
are many features in algae that make them suitable for the bioremediation of heavy
metals; these include high heavy metal tolerance, phototaxy, ability to grow both
autotrophically and heterotrophically, large surface area/volume ratios, phytochelatin
expression, and potential for genetic manipulation (Gaur and Rai 2001). The accumulation of heavy metals by algae provides an advantage for phytoremediation over
other methods that are more costly and not environmental friendly (Khatoon and Pal
2015). Microalgae are effective in nanoparticles synthesis due to their rapid growth
rate to produce large amount of biomass in a very short time and their ability to
accumulate high quantity of metals followed by subsequent reduction to metallic
nanoparticles. Their production costs are also negligible; therefore, the biogenic
mode of nanoparticles synthesis is very important for economic prospects and applications. Moreover, nanoproducts, synthesized from algae, are expected to be biocompatible, therefore minimize environment and public health risks (Khatoon and Pal
2015).
3 Nanoparticles
Nanoparticles are particulate materials that have size ranging from 1 to 100 nm.
They have large surface to volume ratio and many unique physicochemical properties which facilitate their applications in areas like imaging, catalysis, medical
applications, energy-based research, and environmental applications (Khan et al.
2019). They are classified into different groups on the basis of their physicochemical
properties. Those groups include metal NPs, carbon-based NPs, polymeric NPs, and
ceramic NPs. Carbon nanotubes (CNTs) belong to group of carbon-based NPs. They
I. A. Adelere and A. Lateef
health, and others (Caporgno and Mathys 2018; Charles et al. 2019; Koyande et al.
2019; Fields et al. 2020). Microalgae are more important as live feed in aquaculture (Walker and Berlinsky 2011). They are used to feed culture larvae, juvenile
shell, finfish and also for raising the zooplankton required for feeding of juvenile
animals (Taelman et al. 2013). The commonly used microalgae in aquaculture are
species of Chlorella, Tetraselmis, Isochrysis, Pavlova, Phaeodactylum, Chaetoceros,
Nannochloropsis, Skeletonema, and Thalassiosira (Roy and Pal 2015).
The use of biofertilizer is both economical and environment friendly. Members
of cyanobacteria are rich sources of biologically active constituents that can be used
as biofertilizers (Garcia-Gonzalez and Sommerfeld 2016). Cyanobacteria play an
important role in fixing atmospheric nitrogen with the aid of their heterocysts. They
produce complex organic carbon compounds that can bind to soil particles to improve
its quality such as soil structure, soil permeability, and water-holding capacity of
soil (Nisha et al. 2007). Phycoremediation is the process of using microalgae for the
removal or biotransformation of organic pollutants from environments with concomitant biomass propagation (Renuka et al. 2015). The potential of microalgae in metal
biosorption process has been studied extensively due to their ubiquitous occurrence
in nature. Many algal genera are known to have abilities to accumulate heavy metals,
thereby reducing their toxic effects in the environments (Jais et al. 2017). There
are many features in algae that make them suitable for the bioremediation of heavy
metals; these include high heavy metal tolerance, phototaxy, ability to grow both
autotrophically and heterotrophically, large surface area/volume ratios, phytochelatin
expression, and potential for genetic manipulation (Gaur and Rai 2001). The accumulation of heavy metals by algae provides an advantage for phytoremediation over
other methods that are more costly and not environmental friendly (Khatoon and Pal
2015). Microalgae are effective in nanoparticles synthesis due to their rapid growth
rate to produce large amount of biomass in a very short time and their ability to
accumulate high quantity of metals followed by subsequent reduction to metallic
nanoparticles. Their production costs are also negligible; therefore, the biogenic
mode of nanoparticles synthesis is very important for economic prospects and applications. Moreover, nanoproducts, synthesized from algae, are expected to be biocompatible, therefore minimize environment and public health risks (Khatoon and Pal
2015).
3 Nanoparticles
Nanoparticles are particulate materials that have size ranging from 1 to 100 nm.
They have large surface to volume ratio and many unique physicochemical properties which facilitate their applications in areas like imaging, catalysis, medical
applications, energy-based research, and environmental applications (Khan et al.
2019). They are classified into different groups on the basis of their physicochemical
properties. Those groups include metal NPs, carbon-based NPs, polymeric NPs, and
ceramic NPs. Carbon nanotubes (CNTs) belong to group of carbon-based NPs. They