production of different useful byproducts (Savage 2011). Hence, the algal hydrogen
production should always be coupled with the production of other useful bioproducts
which the algae produce. These can minimize the expenses incurred during the scale
up of the process of hydrogen production. The only way forward for enhancing algal
biological hydrogen production is with advances in recombinant DNA technology
and improvements in the design of the bioreactor (FAO 1997). Recombinant DNA
methods should be effectively used for generation of transgenic algae which will be
able to withstand abiotic and biotic stress. Designs in the bioreactor should be
improvised such as using solar cells to entrap light efficiently and minimizing
nutrient loss so as to generate higher rates of hydrogen. Techno-economic analysis
of cultivating algae for generation of hydrogen is important as it gives an indication
about the feasibility of the production process. Selections of efficient strains which
are reengineered for hydrogen production are presently needed. Jmel et al. (2018)
studied different pretreatment techniques on biomass of Ulva lactuca. Chiaramonti
et al. (2017) studied the effect of pyrolysis on microalgae for biofuel generation.
Liao et al. (2018) studied the various kinds of bioreactors which could be used for
generation of bioenergy from microorganism. Banu et al. (2019) studied the effect of
homogenization and sodium tripolyphophate on sea eelgrass for enhancing biofuel
production. Ran et al. (2008) have observed an enhancement in the quantity of
biohydrogen in Platymonas subcordiformis when carbonyl cyanide
m-chlorophenylhydrazone (CCCP) was added. However, the study also opined
that the process may not be sustainable as there would be an interruption of the
proton gradient in thylakoid membranes. Pankratz et al. (2020) have evaluated the
sustainability of microalgae production in cold climates in two kinds of cultivation
systems, namely, open pond raceway (OPR) and photobioreactor (PBR) cultivation.
They suggested that coupling cultivation with supercritical water gasification is
advantageous when compared to the same over pyrolysis of diluent for reduced
emission of greenhouse gases during hydrogen generation. Downregulation of the
light-harvesting proteins will lead to more hydrogen production in the bioreactor
(Oey et al. 2013). The second method of enhancing hydrogen production would be
to lock the electron transport chain (Laurinavichene et al. 2004). Rezvani et al.
(2020) have studied bioremediation potential of Chlorella vulgaris, Ettlia sp., and
Chlamydomonas reinhardtii for nitrate removal along with hydrogen production.
The observed removal rate of nitrate is 86 mg/L/d. Phosphorus removal was less
efficient. Kolbe et al. (2020) suggested using algal generated hydrogen for running
cars. The size, shape, and feasibility for decentralized hydrogen production were
studied for overcoming the limitations being faced by hydrogen-powered cars in the
market.
Bacteria and fungi associated with algae are tabulated in Table 7.6.
Asadi et al. (2017) have done investigations on the feasibility of biofuel generation, its properties, and life cycle and conducted techno-economic analysis for
boosting the biological hydrogen production. The choice of the algal strains chosen,
selection of the site, and cultural conditions have to be optimized. It is best to
204
R. Kumar et al.
production should always be coupled with the production of other useful bioproducts
which the algae produce. These can minimize the expenses incurred during the scale
up of the process of hydrogen production. The only way forward for enhancing algal
biological hydrogen production is with advances in recombinant DNA technology
and improvements in the design of the bioreactor (FAO 1997). Recombinant DNA
methods should be effectively used for generation of transgenic algae which will be
able to withstand abiotic and biotic stress. Designs in the bioreactor should be
improvised such as using solar cells to entrap light efficiently and minimizing
nutrient loss so as to generate higher rates of hydrogen. Techno-economic analysis
of cultivating algae for generation of hydrogen is important as it gives an indication
about the feasibility of the production process. Selections of efficient strains which
are reengineered for hydrogen production are presently needed. Jmel et al. (2018)
studied different pretreatment techniques on biomass of Ulva lactuca. Chiaramonti
et al. (2017) studied the effect of pyrolysis on microalgae for biofuel generation.
Liao et al. (2018) studied the various kinds of bioreactors which could be used for
generation of bioenergy from microorganism. Banu et al. (2019) studied the effect of
homogenization and sodium tripolyphophate on sea eelgrass for enhancing biofuel
production. Ran et al. (2008) have observed an enhancement in the quantity of
biohydrogen in Platymonas subcordiformis when carbonyl cyanide
m-chlorophenylhydrazone (CCCP) was added. However, the study also opined
that the process may not be sustainable as there would be an interruption of the
proton gradient in thylakoid membranes. Pankratz et al. (2020) have evaluated the
sustainability of microalgae production in cold climates in two kinds of cultivation
systems, namely, open pond raceway (OPR) and photobioreactor (PBR) cultivation.
They suggested that coupling cultivation with supercritical water gasification is
advantageous when compared to the same over pyrolysis of diluent for reduced
emission of greenhouse gases during hydrogen generation. Downregulation of the
light-harvesting proteins will lead to more hydrogen production in the bioreactor
(Oey et al. 2013). The second method of enhancing hydrogen production would be
to lock the electron transport chain (Laurinavichene et al. 2004). Rezvani et al.
(2020) have studied bioremediation potential of Chlorella vulgaris, Ettlia sp., and
Chlamydomonas reinhardtii for nitrate removal along with hydrogen production.
The observed removal rate of nitrate is 86 mg/L/d. Phosphorus removal was less
efficient. Kolbe et al. (2020) suggested using algal generated hydrogen for running
cars. The size, shape, and feasibility for decentralized hydrogen production were
studied for overcoming the limitations being faced by hydrogen-powered cars in the
market.
Bacteria and fungi associated with algae are tabulated in Table 7.6.
Asadi et al. (2017) have done investigations on the feasibility of biofuel generation, its properties, and life cycle and conducted techno-economic analysis for
boosting the biological hydrogen production. The choice of the algal strains chosen,
selection of the site, and cultural conditions have to be optimized. It is best to
204
R. Kumar et al.