9.3 Chemistry of Laminarin
195
9.3.5 Biodegradation of Laminarin
Laminarin degrades into its repeating units which are glucose and other reducing
sugars such as mannose. Microbes which metabolize these laminarinase include C.
cinerea and Microbacterium oxydans (Kim et al. 2013). At an inoculum volume concentration of 20% (v/v), pH 6.0, and a temperature of 30 °C, a 10 g L
−1 concentration
of laminarin substrate produced 5.11 g L
−1 of reducing sugars and 2.88 g L
−1 glucose after a 6-day culture period using M. oxydans (Kim et al. 2013). The microbial
degradation of laminarin into simple sugars is important both for safe environmental
purpose and for commercialization of the sugars.
9.3.6 Chrysolaminarin
It is important to mention here, chrysolaminarin, also referred to as leucosin, another
biopolymer found in unicellular algae (Beattie et al. 1961). Diatoms are part of the
plankton and benthic algae which serve as a significant part of the aquatic food
chain. Diatoms have been used in art and are continuously studied for wide variety
of potential applications to advance human life such as use in photo-induced green
synthesis of nanoparticles (Chetia et al. 2017). Diatoms produce a polysaccharide
which is similar to laminarin known as chrysolaminarin. It is synthesized during the
day in the presence of light and used up at night to fuel heterotrophic metabolic activities (Caballero et al. 2016). The similarity in these two polysaccharides lies in the
fact that they are both made up of β,1-3 glucose and both water-soluble polysaccharides. Chrysolaminarin contains up to 99.5% glucose repeating units while laminarin
has other units, mainly mannitol within the structure. There are no mannitol units
present in chrysolaminarin (Beattie et al. 1961). Chrysolaminarin is a linear polymer and has a more crystalline secondary structure while laminarin could have low
or high level of branching. While laminarin serves as the storage polysaccharides
for the Phaeophyceae, chrysolaminarin serves as the storage polysaccharides for the
diatoms. Chrysolaminarin makes up between 12 and 33% dry weight of the diatom.
This could be up to 80% when grown at optimal conditions for chrysolaminarin
production (Hildebrand et al. 2017). Due to their simpler structure, other than the
potential bioactivities, chrysolaminarin has a potential to serve as a source of glucose
for ethanol production.
9.4 Availability of Raw Material
Laminarin can be sourced from a variety of brown algae which grow in different
marine areas. According to FAO in 2016, 31.2 million tonnes of algae are produced in 2016 (FAO 2018). Of this total, 34,000 tonnes of brown algae live weight
195
9.3.5 Biodegradation of Laminarin
Laminarin degrades into its repeating units which are glucose and other reducing
sugars such as mannose. Microbes which metabolize these laminarinase include C.
cinerea and Microbacterium oxydans (Kim et al. 2013). At an inoculum volume concentration of 20% (v/v), pH 6.0, and a temperature of 30 °C, a 10 g L
−1 concentration
of laminarin substrate produced 5.11 g L
−1 of reducing sugars and 2.88 g L
−1 glucose after a 6-day culture period using M. oxydans (Kim et al. 2013). The microbial
degradation of laminarin into simple sugars is important both for safe environmental
purpose and for commercialization of the sugars.
9.3.6 Chrysolaminarin
It is important to mention here, chrysolaminarin, also referred to as leucosin, another
biopolymer found in unicellular algae (Beattie et al. 1961). Diatoms are part of the
plankton and benthic algae which serve as a significant part of the aquatic food
chain. Diatoms have been used in art and are continuously studied for wide variety
of potential applications to advance human life such as use in photo-induced green
synthesis of nanoparticles (Chetia et al. 2017). Diatoms produce a polysaccharide
which is similar to laminarin known as chrysolaminarin. It is synthesized during the
day in the presence of light and used up at night to fuel heterotrophic metabolic activities (Caballero et al. 2016). The similarity in these two polysaccharides lies in the
fact that they are both made up of β,1-3 glucose and both water-soluble polysaccharides. Chrysolaminarin contains up to 99.5% glucose repeating units while laminarin
has other units, mainly mannitol within the structure. There are no mannitol units
present in chrysolaminarin (Beattie et al. 1961). Chrysolaminarin is a linear polymer and has a more crystalline secondary structure while laminarin could have low
or high level of branching. While laminarin serves as the storage polysaccharides
for the Phaeophyceae, chrysolaminarin serves as the storage polysaccharides for the
diatoms. Chrysolaminarin makes up between 12 and 33% dry weight of the diatom.
This could be up to 80% when grown at optimal conditions for chrysolaminarin
production (Hildebrand et al. 2017). Due to their simpler structure, other than the
potential bioactivities, chrysolaminarin has a potential to serve as a source of glucose
for ethanol production.
9.4 Availability of Raw Material
Laminarin can be sourced from a variety of brown algae which grow in different
marine areas. According to FAO in 2016, 31.2 million tonnes of algae are produced in 2016 (FAO 2018). Of this total, 34,000 tonnes of brown algae live weight