11.2 Occurrence in Nature
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and little life or organic matter exists to feed on. Other wood-digesting organisms
which live in the higher zones of the water like shipworms and piddocks also exist.
The activity of the enzymes and optimal conditions for activity vary as a result of
the difference in the conditions under which these organisms exist.
This adaptation to extreme conditions gives enzymes sourced from these
extremophiles the particular advantage of having relatively higher activities at
extreme conditions (Fernandes 2016). Since the aquatic organisms which are the
source of these enzymes are adapted to processing food and metabolic activities
using these enzymes at such extreme conditions, the enzymes they produce for these
activities are therefore conformed to retain their activity at such conditions. Such
property becomes commercially useful where products such as food and pharmaceutics need to be processed at extreme conditions while retaining the activity of the
enzymes.
Enzymes are therefore abundant in the aquatic environment and are present in a
diverse range of organisms. Their occurrence in a diverse range of conditions such
as temperature, salinity, pH, pressure and light intensity gives rise to the availability
of enzymes that are optimally active in more varied conditions compared to enzymes
sourced from terrestrial organisms. The fact that the aquatic environment makes up a
larger portion of the earth and hosts more diversity of organism also results in more
naturally occurring enzymes in the aquatic environment.
11.3 Chemistry of Some Aquatic Enzymes
Enzymes are mostly proteins (some enzymes exist that are not proteins), chains of
amino acids linked together by peptide bonds. Amino acids being the repeating units
of these proteins are a diverse class of compounds which are characterized by the
presence of an amine and a carboxylic acid group attached to an alkyl. Enzymes can
have molecular weights in the thousands to tens of thousands range. Proteinase A,
for example, has a molecular mass of 50 kDa, while proteinase B has a molecular
mass of 95 kDa (Komori and Nikai 2013).
The functioning of an enzyme depends on the primary, secondary and tertiary
structure of the enzyme. Most enzymes are globular proteins which fold up in specific patterns in their tertiary structure. This unique tertiary structure allows them
to combine with specific substrates in a unique manner and by so doing catalyzes
specific processes. The activity of enzymes varies at different conditions. For example, alkaline proteinase will act at pH above 7, while acid proteinase will act at the
low end of pH and lipases will only act at the interface between water and oil since
lipase is hydrophilic and the triglyceride it breaks down is hydrophobic (Bele et al.
2014a, b). Therefore, unlike nutritional protein which is required to be broken down
to produce amino acids which are then utilized in this form, enzymes are required to
retain their tertiary structures in order to serve their purpose.
Some enzymes are specific to particular bonds, while some can catalyze a wide
range of processes. For example, lipases catalyze the breakdown of fats to produce
239
and little life or organic matter exists to feed on. Other wood-digesting organisms
which live in the higher zones of the water like shipworms and piddocks also exist.
The activity of the enzymes and optimal conditions for activity vary as a result of
the difference in the conditions under which these organisms exist.
This adaptation to extreme conditions gives enzymes sourced from these
extremophiles the particular advantage of having relatively higher activities at
extreme conditions (Fernandes 2016). Since the aquatic organisms which are the
source of these enzymes are adapted to processing food and metabolic activities
using these enzymes at such extreme conditions, the enzymes they produce for these
activities are therefore conformed to retain their activity at such conditions. Such
property becomes commercially useful where products such as food and pharmaceutics need to be processed at extreme conditions while retaining the activity of the
enzymes.
Enzymes are therefore abundant in the aquatic environment and are present in a
diverse range of organisms. Their occurrence in a diverse range of conditions such
as temperature, salinity, pH, pressure and light intensity gives rise to the availability
of enzymes that are optimally active in more varied conditions compared to enzymes
sourced from terrestrial organisms. The fact that the aquatic environment makes up a
larger portion of the earth and hosts more diversity of organism also results in more
naturally occurring enzymes in the aquatic environment.
11.3 Chemistry of Some Aquatic Enzymes
Enzymes are mostly proteins (some enzymes exist that are not proteins), chains of
amino acids linked together by peptide bonds. Amino acids being the repeating units
of these proteins are a diverse class of compounds which are characterized by the
presence of an amine and a carboxylic acid group attached to an alkyl. Enzymes can
have molecular weights in the thousands to tens of thousands range. Proteinase A,
for example, has a molecular mass of 50 kDa, while proteinase B has a molecular
mass of 95 kDa (Komori and Nikai 2013).
The functioning of an enzyme depends on the primary, secondary and tertiary
structure of the enzyme. Most enzymes are globular proteins which fold up in specific patterns in their tertiary structure. This unique tertiary structure allows them
to combine with specific substrates in a unique manner and by so doing catalyzes
specific processes. The activity of enzymes varies at different conditions. For example, alkaline proteinase will act at pH above 7, while acid proteinase will act at the
low end of pH and lipases will only act at the interface between water and oil since
lipase is hydrophilic and the triglyceride it breaks down is hydrophobic (Bele et al.
2014a, b). Therefore, unlike nutritional protein which is required to be broken down
to produce amino acids which are then utilized in this form, enzymes are required to
retain their tertiary structures in order to serve their purpose.
Some enzymes are specific to particular bonds, while some can catalyze a wide
range of processes. For example, lipases catalyze the breakdown of fats to produce