10.2 Occurrence in Nature
213
Table 10.1 Protein yields
from some aquatic plants and
algae
Organism
Protein yield (%) References
Kappaphycus
alvarezii
12.69–23.61
Kumar et al. (2015)
Undaria pinnatifida 15
Suetsuna and
Nakano (2000)
Azolla (water fern) 28
Brouwer et al.
(2019)
Lemna gibba
duckweed
21.5
Aguilera-Morales
et al. (2018)
Ulva lactuca
17.2
Aguilera-Morales
et al. (2018)
P. tenera (red
algae)
47
Fleurence (1999)
Nannochloropsis
gaditana
(microalgae)
17.4 and 24.8
Safi et al. (2017)
Spirulina platensis
(blue-green algae)
29.05
Yucetepe et al.
(2018)
of commercial value. The rate of accumulation of each polymer varies; furthermore,
the optimal conditions for maximum accumulation of one polymer are most likely
not the optimal condition for the others. For example, the red marine alga Porphyridium marinum contains up 46% protein by dry weight when grown in medium with
17.6 mM potassium nitrate. However, when grown with 5.9 mM potassium nitrate,
the protein content is 35% and when grown with 3.5% mM potassium nitrate, the
protein content is even lower at 25% dry weight (Li et al. 2019). This red microalgae accumulates maximum starch at light intensity of 100 µmol photons m
−2 s
−1 ,
sodium nitrate (NaNO 3 ) concentration of 1 g/L and a sodium chloride concentration
of 20 g/L (Hlima et al. 2019). However, this condition is not the optimal condition
for protein accumulation. Furthermore, while the starch content increases the light
intensity and salinity of growth environment increases the starch content in these
algae, it does the opposite for the protein content. This is explained to be as a result
of the conditions favoring biochemical processes which lead to starch formation that
does not favor those biochemical reactions leading to protein formation. Table 10.1
gives yields of protein obtained from different species based on values reported from
different studies in the literature.
10.3 Chemistry of Aquatic Proteins
Proteins are polymeric structures made up of polypeptides which are chains made
up of several amino acids which are repeating units joined together by amide links
that links the amine group with a carboxylic acid group. They are heteropolymers
213
Table 10.1 Protein yields
from some aquatic plants and
algae
Organism
Protein yield (%) References
Kappaphycus
alvarezii
12.69–23.61
Kumar et al. (2015)
Undaria pinnatifida 15
Suetsuna and
Nakano (2000)
Azolla (water fern) 28
Brouwer et al.
(2019)
Lemna gibba
duckweed
21.5
Aguilera-Morales
et al. (2018)
Ulva lactuca
17.2
Aguilera-Morales
et al. (2018)
P. tenera (red
algae)
47
Fleurence (1999)
Nannochloropsis
gaditana
(microalgae)
17.4 and 24.8
Safi et al. (2017)
Spirulina platensis
(blue-green algae)
29.05
Yucetepe et al.
(2018)
of commercial value. The rate of accumulation of each polymer varies; furthermore,
the optimal conditions for maximum accumulation of one polymer are most likely
not the optimal condition for the others. For example, the red marine alga Porphyridium marinum contains up 46% protein by dry weight when grown in medium with
17.6 mM potassium nitrate. However, when grown with 5.9 mM potassium nitrate,
the protein content is 35% and when grown with 3.5% mM potassium nitrate, the
protein content is even lower at 25% dry weight (Li et al. 2019). This red microalgae accumulates maximum starch at light intensity of 100 µmol photons m
−2 s
−1 ,
sodium nitrate (NaNO 3 ) concentration of 1 g/L and a sodium chloride concentration
of 20 g/L (Hlima et al. 2019). However, this condition is not the optimal condition
for protein accumulation. Furthermore, while the starch content increases the light
intensity and salinity of growth environment increases the starch content in these
algae, it does the opposite for the protein content. This is explained to be as a result
of the conditions favoring biochemical processes which lead to starch formation that
does not favor those biochemical reactions leading to protein formation. Table 10.1
gives yields of protein obtained from different species based on values reported from
different studies in the literature.
10.3 Chemistry of Aquatic Proteins
Proteins are polymeric structures made up of polypeptides which are chains made
up of several amino acids which are repeating units joined together by amide links
that links the amine group with a carboxylic acid group. They are heteropolymers