Chapter 9
Laminarins
Abstract Laminarins are short-chain polysaccharides present in the cell wall of
brown algae. The simple structure of short-chain 1-3 linked β glucose unit that makes
it attractive in bioethanol production. Laminarin also has some bioactive properties
which are of research interests and potential commercial application. Extraction of
laminarin from brown algae can be carried out alongside the extraction of the other
polysaccharides in the brown algae cell wall, such that it contributes toward more
efficient utilization of the algal biomass. This chapter reviews the production process
and evaluates the environmental impacts of laminarin production, the commercial
potential in terms of availability of raw material as well as existing and potential applications. The occurrence of laminarin in nature and its chemistry are also presented
within the chapter.
Keywords Laminarins · Algae · Bioethanol · Aquatic · Biopolymer
9.1 Introduction
Laminarin is a type of sulfated polysaccharide found in brown algae. It serves as a
storage polysaccharide. Also referred to as laminarans, they are soluble polysaccharides found in algae. The main repeating unit in laminarin structure is a 1-3 linked
β glucose unit. Some branching at the β 1-6 linkage is not uncommon in laminarin
chains, and other units such as mannitol and mannose have been reported to be present
along some laminarin polymer chains (Yvin et al. 1993). They are usually short-chain
polysaccharides with a degree of polymerization between 26 and 31 (Deville et al.
2007) or up to 60 repeating units (Yvin et al. 1993). Algae species such as Ecklonia
kurome, Laminaria japonica, Laminaria digitata and Eisenia bicyclis contain laminarin. They belong to the group of polysaccharides known as glucans, a diverse group
of polymers made up of glucose repeating units. These glucans vary in terms of the
orientation and linkages of these repeating units, which can be in forms such as alpha
or β, linear or branched, L or D forms (Caipang and Lazado 2015). Glucans also have
varying chain lengths from short-chain oligomers in tens of repeating units or less
to long-chain polymer structures with thousands of repeating units. Other examples
of glucans are cellulose and starch. Glucans exist in a variety of organisms such as
© Springer International Publishing 2020
O. Olatunji, Aquatic Biopolymers, Springer Series on Polymer and Composite Materials,
https://doi.org/10.1007/978-3-030-34709-3_9
189
Laminarins
Abstract Laminarins are short-chain polysaccharides present in the cell wall of
brown algae. The simple structure of short-chain 1-3 linked β glucose unit that makes
it attractive in bioethanol production. Laminarin also has some bioactive properties
which are of research interests and potential commercial application. Extraction of
laminarin from brown algae can be carried out alongside the extraction of the other
polysaccharides in the brown algae cell wall, such that it contributes toward more
efficient utilization of the algal biomass. This chapter reviews the production process
and evaluates the environmental impacts of laminarin production, the commercial
potential in terms of availability of raw material as well as existing and potential applications. The occurrence of laminarin in nature and its chemistry are also presented
within the chapter.
Keywords Laminarins · Algae · Bioethanol · Aquatic · Biopolymer
9.1 Introduction
Laminarin is a type of sulfated polysaccharide found in brown algae. It serves as a
storage polysaccharide. Also referred to as laminarans, they are soluble polysaccharides found in algae. The main repeating unit in laminarin structure is a 1-3 linked
β glucose unit. Some branching at the β 1-6 linkage is not uncommon in laminarin
chains, and other units such as mannitol and mannose have been reported to be present
along some laminarin polymer chains (Yvin et al. 1993). They are usually short-chain
polysaccharides with a degree of polymerization between 26 and 31 (Deville et al.
2007) or up to 60 repeating units (Yvin et al. 1993). Algae species such as Ecklonia
kurome, Laminaria japonica, Laminaria digitata and Eisenia bicyclis contain laminarin. They belong to the group of polysaccharides known as glucans, a diverse group
of polymers made up of glucose repeating units. These glucans vary in terms of the
orientation and linkages of these repeating units, which can be in forms such as alpha
or β, linear or branched, L or D forms (Caipang and Lazado 2015). Glucans also have
varying chain lengths from short-chain oligomers in tens of repeating units or less
to long-chain polymer structures with thousands of repeating units. Other examples
of glucans are cellulose and starch. Glucans exist in a variety of organisms such as
© Springer International Publishing 2020
O. Olatunji, Aquatic Biopolymers, Springer Series on Polymer and Composite Materials,
https://doi.org/10.1007/978-3-030-34709-3_9
189