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20 Application of Sustainable Micro-Algal Species in the Production of Bioenergy

These nanoparticles extract oil from livelihood algae without killing them. The

nanoparticles draw oil by carefully entrapping the lipid molecules produced by the

selected algal strain between the cell membrane and the cell wall. The sponge-like

mesoporous nanoparticles are used without disturbing cell membrane. The oil thus

produced within the rigid space is absorbed into the pores of the sponge-like struc-

ture of the catalyst. To enable the transesterification of the entrapped lipids, oxides of

calcium and strontium are fed into the pore structure of the nanoparticles. Recently,

nanoporous carbons are also used as adsorbents for biofuel separation. [18]

20.2.7.5

Biohydrogen Production by Photobiological Process

Microalgae which are photosynthetic use solar energy to generate hydrogen gas from

water. Among various species of microalgae, Chlamydomonas reinhardtiii is consid-

ered for producing H2. The catalysts photosystem II (PSII) and Fe–Fe hydrogenase

are used in this process. The biochemical reaction occurs among H2O and H2 in the

presence of the light energy. Biophotolysis is divided into two categories: direct and

indirect biophotolysis. Direct biophotolysis is the PSII-dependent pathway, in which

there is a direct link of water-splitting activity to H2 evolution. Indirect biophotoly-

sis is the PSII-independent pathway. Concentration is required for it to be promoted

as a technology for enhancing great environmental benefits. There is a wide oppor-

tunity for research in this area mainly about technological and economical barriers

concerning this process. [19]

20.3

Genetic Engineering for the Improvement

of Microalgae

Genetic manipulation is a cost-effective strategy for moving forward the algal-based

production. Microalgae genetic manipulation provides various advantages to the

biotech industry. Selected algal species will increase productivity with novel cultiva-

tion techniques. Harvesting and downstream processing can be greatly enhanced.

This process reduces energy inputs, increases stability, and minimizes extraction

costs. The focus of microalgae strains research is to develop single microalgae

“super-strain” to improve the profitability of the production process, and prof-

itability, identification, and isolation of the algal strains for commercialization of

bioproducts.

Genetic engineering process facilitates the manipulation of the genome of the

microalgae. C. reinhardtii was the first microalgae to have its genome sequenced.

Evolution of newer sequencing technologies facilitated the genome sequencing of

various strains. To insert foreign DNA into microalgae, various protocols have been

developed. Some of them are biolistic, electroporation, and agrobacterium-mediated

transformations. These protocols are widely used in plant applications and are

adopted because of similar characteristics of their cell wall. Natural strains cause

less environmental harm which is not in the case of genetically modified microal-

gae, depending on the type of manipulation involved. The microbial cultivation of

genetically modified microalgae can be done in closed or open ponds. Open ponds