10. Algae have been reported to produce 30–100 times more energy in a given area
(per hectare) in comparison to terrestrial energy crops (Demirbas 2010).
The concept of biofuel production from microalgae is not new (Chisti 1980) but
presently is being followed up critically because of soaring petro fuel prices and the
planetary emergency of global warming associated with fossil fuel burning
(Gavrilescu and Chisti 2005). The Arab embargo of the 1970s gave a new thrust
to the field of microalgal biofuel. The Department of Energy’s Office of Fuels
Development (United States of America) launched the historic Aquatic Species
Program (ASP) in 1978. This research project investigated biodiesel production
from oleaginous algal isolates which were grown in ponds, and utilized waste carbon
dioxide from coal fired power plants (Sheehan et al. 1998). The ASP was later on
discontinued in 1996 owing to budget curbing, but however the status report of ASP
serves as an excellent blueprint for initiating research in microalgal bioenergy.
Despite the ASP out of the scenario research continued in this domain and now is
well evident with tons of scientific literatures being available in the scientific
repositories. There are substantial scientific efforts underway worldwide to investigate the probability of renewable biofuel production from various species of
microalgae. The most important in this regard are methane (here in algal biomass
is subjected to anaerobic digestion) (Spolaore et al. 2006), microalgal oil derived
biodiesel (Chisti 2007), photo-biologically produced bio-hydrogen (Fedorov et al.
2005), and pyrolytic bio-oil produced by thermo-chemical conversion (Pan et al.
2010). Biofuel production from microalgal biomass is possible both in theory and
practice and considering the present energy scenario is of global importance. Biofuel
from microalgae indisputably appears to be promising in context of the existent
energy shortage scenario; however, a critical impediment to their successful commercial implementation is the reasonably cheaper rates of petro fuels.
7.2
Non-energy Based Prospects
Apart from energy based products microalgae have other potential role such as in
food additive, nutraceutical, biomedical domain, etc. Figure 7.1 shows the potential
use of microalgae other than its role in energy based products. Microalgae are wellknown rich source of high value bio-actives such as carotenoids, antioxidants,
proteins, etc., which enhances the nutritional value of the food supplements
(Hudek et al. 2014). Lutein which is a predominant carotenoid is found in many
microalgae like Muriellopsis sp., Scenedesmus almeriensis, Chlorella sp., etc., and
has a very high nutraceutical value (Guedes et al. 2011). Apart from Lutein,
Astaxanthin and β-carotene are other carotenoids which have the potential nutraceutical values. Many microalgae like Chlamydomonas, Chlorella, Oscillatoria,
Scenedesmus, Micractinium, Dunaliella, Spirulina, and Euglena are well known
for their high protein content which may be up to 50% of their dry weight (Islam et
al. 2017). In Human muscle proteins; lysine, leucine, isoleucine, and valine amino
acids are predominantly present, which account for nearly 35% of all amino acids.
7 Aquatic Microbial Oxygenic Phototrophs: A Short Treatise on Diverse. . .
137
(per hectare) in comparison to terrestrial energy crops (Demirbas 2010).
The concept of biofuel production from microalgae is not new (Chisti 1980) but
presently is being followed up critically because of soaring petro fuel prices and the
planetary emergency of global warming associated with fossil fuel burning
(Gavrilescu and Chisti 2005). The Arab embargo of the 1970s gave a new thrust
to the field of microalgal biofuel. The Department of Energy’s Office of Fuels
Development (United States of America) launched the historic Aquatic Species
Program (ASP) in 1978. This research project investigated biodiesel production
from oleaginous algal isolates which were grown in ponds, and utilized waste carbon
dioxide from coal fired power plants (Sheehan et al. 1998). The ASP was later on
discontinued in 1996 owing to budget curbing, but however the status report of ASP
serves as an excellent blueprint for initiating research in microalgal bioenergy.
Despite the ASP out of the scenario research continued in this domain and now is
well evident with tons of scientific literatures being available in the scientific
repositories. There are substantial scientific efforts underway worldwide to investigate the probability of renewable biofuel production from various species of
microalgae. The most important in this regard are methane (here in algal biomass
is subjected to anaerobic digestion) (Spolaore et al. 2006), microalgal oil derived
biodiesel (Chisti 2007), photo-biologically produced bio-hydrogen (Fedorov et al.
2005), and pyrolytic bio-oil produced by thermo-chemical conversion (Pan et al.
2010). Biofuel production from microalgal biomass is possible both in theory and
practice and considering the present energy scenario is of global importance. Biofuel
from microalgae indisputably appears to be promising in context of the existent
energy shortage scenario; however, a critical impediment to their successful commercial implementation is the reasonably cheaper rates of petro fuels.
7.2
Non-energy Based Prospects
Apart from energy based products microalgae have other potential role such as in
food additive, nutraceutical, biomedical domain, etc. Figure 7.1 shows the potential
use of microalgae other than its role in energy based products. Microalgae are wellknown rich source of high value bio-actives such as carotenoids, antioxidants,
proteins, etc., which enhances the nutritional value of the food supplements
(Hudek et al. 2014). Lutein which is a predominant carotenoid is found in many
microalgae like Muriellopsis sp., Scenedesmus almeriensis, Chlorella sp., etc., and
has a very high nutraceutical value (Guedes et al. 2011). Apart from Lutein,
Astaxanthin and β-carotene are other carotenoids which have the potential nutraceutical values. Many microalgae like Chlamydomonas, Chlorella, Oscillatoria,
Scenedesmus, Micractinium, Dunaliella, Spirulina, and Euglena are well known
for their high protein content which may be up to 50% of their dry weight (Islam et
al. 2017). In Human muscle proteins; lysine, leucine, isoleucine, and valine amino
acids are predominantly present, which account for nearly 35% of all amino acids.
7 Aquatic Microbial Oxygenic Phototrophs: A Short Treatise on Diverse. . .
137