64 Marine Macro- and Microalgae: An Overview
viable products besides fuel (Philip et al. 2011). Among the eukaryotes, green algae are the most referred
oil-rich microalgae. They are ubiquitous in a variety of habitats and grow faster than other taxa, and as
much as 60% of their cell dry weight is enriched with oils. However, the composition of the oils is highly
dependent on the species and the conditions in which the algae grow.
Oils that are rich in neutral lipids are desirable in a biofuel context because of their potential high
fuel yield. Because TAGs are made up of three molecules of fatty acids that are esterified-or altered-to
one molecule of glycerol, close to 100% of their weight can be converted into fuels. With polar lipids,
on the other hand, only one or two fatty-acid molecules are esterified to glycerol and the remaining
components (e.g., sugars or phosphate groups) cannot be converted to fuel feedstock. As a result, these
types of lipids generate lower fuel yields (Philip et al. 2011). Two thirds of the earth’s surface is covered
with ocean, thus algae would be an option of great potential for food including aquaculture industries,
pharma products, and global energy needs. Many countries have started to grow algae on ocean beds in
floating transparent light weight tubes (e.g., Malaysia, Denmark, and USA). These projects are explained
in OASIS and NASA OMEGA projects. Currently these set-ups are in trial to be a huge project soon.
Fig. 1. Few commercially important microalgal strains. (a) Spirulina maxima, (b) Botryococcus brauanii, (c) Scenedesmus
quadricauda, (d) Chlorella vulgaris, (e) Dunaliella salina, and (f) Chaetoceros muelleri.
Selection of new strains
The marine microalgae strains suitable for maximum biomass production requires a lot of important
characters ideally (quantitatively) measurable. The use of locally selected strains may be of significance
both for ease of management and for reasons of sustainability. An outdoor microalgal cultivation would help
to achieve maximum as well optimum biomass production in large scale systems and commercialization
of products such as fine chemicals, nutraceutical, and lipids. Total biomass composition includes total
caloric value of the biomass, % lipids and lipid composition (for biodiesel), % starch and carbohydrate
composition (for bioethanol and to identify higher value byproducts), % protein and protein composition
(soluble/insoluble for food/feed purposes). Presence of heavy metals or toxins and should include
relevant aspects for biorefinery, such as the cell volume, thickness/toughness of the cell wall, the presence
of tough fibers (macroalgae), and the moisture content. A measure for this could be the energy input per
gram of dry weight necessary for full biorefinery. It is very important to check if the organism produces
any byproduct that have an intrinsic added value, such as carotenoids. This is important to reduce the
costs of the final product. Here a specification of the compounds and their expected added value per gram
of dry biomass should be indicated.
viable products besides fuel (Philip et al. 2011). Among the eukaryotes, green algae are the most referred
oil-rich microalgae. They are ubiquitous in a variety of habitats and grow faster than other taxa, and as
much as 60% of their cell dry weight is enriched with oils. However, the composition of the oils is highly
dependent on the species and the conditions in which the algae grow.
Oils that are rich in neutral lipids are desirable in a biofuel context because of their potential high
fuel yield. Because TAGs are made up of three molecules of fatty acids that are esterified-or altered-to
one molecule of glycerol, close to 100% of their weight can be converted into fuels. With polar lipids,
on the other hand, only one or two fatty-acid molecules are esterified to glycerol and the remaining
components (e.g., sugars or phosphate groups) cannot be converted to fuel feedstock. As a result, these
types of lipids generate lower fuel yields (Philip et al. 2011). Two thirds of the earth’s surface is covered
with ocean, thus algae would be an option of great potential for food including aquaculture industries,
pharma products, and global energy needs. Many countries have started to grow algae on ocean beds in
floating transparent light weight tubes (e.g., Malaysia, Denmark, and USA). These projects are explained
in OASIS and NASA OMEGA projects. Currently these set-ups are in trial to be a huge project soon.
Fig. 1. Few commercially important microalgal strains. (a) Spirulina maxima, (b) Botryococcus brauanii, (c) Scenedesmus
quadricauda, (d) Chlorella vulgaris, (e) Dunaliella salina, and (f) Chaetoceros muelleri.
Selection of new strains
The marine microalgae strains suitable for maximum biomass production requires a lot of important
characters ideally (quantitatively) measurable. The use of locally selected strains may be of significance
both for ease of management and for reasons of sustainability. An outdoor microalgal cultivation would help
to achieve maximum as well optimum biomass production in large scale systems and commercialization
of products such as fine chemicals, nutraceutical, and lipids. Total biomass composition includes total
caloric value of the biomass, % lipids and lipid composition (for biodiesel), % starch and carbohydrate
composition (for bioethanol and to identify higher value byproducts), % protein and protein composition
(soluble/insoluble for food/feed purposes). Presence of heavy metals or toxins and should include
relevant aspects for biorefinery, such as the cell volume, thickness/toughness of the cell wall, the presence
of tough fibers (macroalgae), and the moisture content. A measure for this could be the energy input per
gram of dry weight necessary for full biorefinery. It is very important to check if the organism produces
any byproduct that have an intrinsic added value, such as carotenoids. This is important to reduce the
costs of the final product. Here a specification of the compounds and their expected added value per gram
of dry biomass should be indicated.