190
9 Laminarins
yeast, bacteria and algae. Laminarins can therefore be described as short-chain β
glucans with some degree of branching.
There is an increasing need for alternative sources of energy as the conventional
fossil fuels are being depleted exponentially as the population rises globally. While
crops such as corn and sugarcane are sources of carbohydrates which can be further
hydrolyzed and fermented into ethanol used as biofuel, the main issue with such
sources of alternative fuel is the competition with food, water and land for human
consumption and use for survival. Other crops which are sources of polymeric materials such as gum arabic have these similar issues. Laminarin is sourced from brown
algae, and this addresses half of the issues of other alternative fuels and biomaterials.
Laminarin is a glucan which can be hydrolyzed to glucose and other simple sugars
which can be fermented by microbes which in turn produce ethanol as a by-product.
As the world population grows, there is increasing demand to keep people alive
and disease-free. Furthermore, as disease resistance of bacteria to conventional drugs
increases, there is a need for more complex compounds for combating diseases and
improving immunity. For this reason, exploring naturally occurring polymers such
as laminarin for their bioactivities such as immunomodulatory and antimicrobial
activity becomes more important.
In this chapter, we explore another interesting biopolymer which can be obtained
from an aquatic organism, the brown algae, laminarin. The sources of laminarin,
chemical structure, applications and the environmental impacts of laminarin extraction process are all discussed with the reference to various recent studies from
different research studies around the world.
9.2 Occurrence in Nature
Glucans, in general, exist in yeast, bacteria, mushrooms, grains of cereals and algae
(Caipang and Lazado 2015). In brown algae, laminarin exists in the plastids where it
serves as a storage polysaccharide (Rioux and Turgeon 2015). Brown algae contain
~40% polysaccharides by dry weight (Deville et al. 2007), and one of these polysaccharides could include laminarin. Brown algae which are sources of laminations are
referred to as Laminariales (Yvin et al. 1993). While alginate serves as a structural
polysaccharide in brown algae, laminarin serves as a storage polysaccharide (Konda
et al. 2015). The laminarin content could vary from 0 to 18% (Rioux and Turgeon
2015; Konda et al. 2015) in different species of brown algae, other studies report
higher laminarin content of up to 35% laminarin per dry mass of brown macroalgae
(Motone et al. 2016).
Storage polysaccharides generally have simpler structures such that they can easily be broken down to release energy and carbon when required by the organism.
Laminarin content in any given species varies in different growing seasons and growth
conditions. For instance, at low nitrate and nitrite content in the water, brown algae
proceed to produce laminarin as a stored carbon source; however, where nitrate and
nitrite are present, the brown algae directs its energy toward growth (Rioux and
9 Laminarins
yeast, bacteria and algae. Laminarins can therefore be described as short-chain β
glucans with some degree of branching.
There is an increasing need for alternative sources of energy as the conventional
fossil fuels are being depleted exponentially as the population rises globally. While
crops such as corn and sugarcane are sources of carbohydrates which can be further
hydrolyzed and fermented into ethanol used as biofuel, the main issue with such
sources of alternative fuel is the competition with food, water and land for human
consumption and use for survival. Other crops which are sources of polymeric materials such as gum arabic have these similar issues. Laminarin is sourced from brown
algae, and this addresses half of the issues of other alternative fuels and biomaterials.
Laminarin is a glucan which can be hydrolyzed to glucose and other simple sugars
which can be fermented by microbes which in turn produce ethanol as a by-product.
As the world population grows, there is increasing demand to keep people alive
and disease-free. Furthermore, as disease resistance of bacteria to conventional drugs
increases, there is a need for more complex compounds for combating diseases and
improving immunity. For this reason, exploring naturally occurring polymers such
as laminarin for their bioactivities such as immunomodulatory and antimicrobial
activity becomes more important.
In this chapter, we explore another interesting biopolymer which can be obtained
from an aquatic organism, the brown algae, laminarin. The sources of laminarin,
chemical structure, applications and the environmental impacts of laminarin extraction process are all discussed with the reference to various recent studies from
different research studies around the world.
9.2 Occurrence in Nature
Glucans, in general, exist in yeast, bacteria, mushrooms, grains of cereals and algae
(Caipang and Lazado 2015). In brown algae, laminarin exists in the plastids where it
serves as a storage polysaccharide (Rioux and Turgeon 2015). Brown algae contain
~40% polysaccharides by dry weight (Deville et al. 2007), and one of these polysaccharides could include laminarin. Brown algae which are sources of laminations are
referred to as Laminariales (Yvin et al. 1993). While alginate serves as a structural
polysaccharide in brown algae, laminarin serves as a storage polysaccharide (Konda
et al. 2015). The laminarin content could vary from 0 to 18% (Rioux and Turgeon
2015; Konda et al. 2015) in different species of brown algae, other studies report
higher laminarin content of up to 35% laminarin per dry mass of brown macroalgae
(Motone et al. 2016).
Storage polysaccharides generally have simpler structures such that they can easily be broken down to release energy and carbon when required by the organism.
Laminarin content in any given species varies in different growing seasons and growth
conditions. For instance, at low nitrate and nitrite content in the water, brown algae
proceed to produce laminarin as a stored carbon source; however, where nitrate and
nitrite are present, the brown algae directs its energy toward growth (Rioux and