11.7 Environmental Implications
251
of 1:10 as a minimal used in similar extraction processes, we can estimate that a
minimum of 20 ml of water is used in the extraction of enzyme from 1 g of algae.
11.7.4 Use of Salts and Buffers
Where ammonium sulfate is used, this eventually breaks down into nitrogen, hydrogen and sulfate which can be taken up by plants and other organisms if adequately
disposed of. Unlike other more intensive processes such as the extraction of chitin
from crustacean shells or extraction of collagen from animal tissue which makes use
of strong acids and alkali, enzyme extraction is relatively milder and requires use of
milder chemicals.
11.7.5 Energy Consumption
The homogenization of the algae biomass into powdered form achieves improved
release of the proteins into water as a result of reduced particle size and mechanical disruption, and this process requires significant amounts of energy. Drying of
the samples prior to homogenizing reduces the amount of energy consumed in this
process. The quantity of energy consumed at this stage varies depending on the
machinery used and the efficiency.
The drying process is done at ambient conditions; high-temperature oven-drying
is not an option here as this will result in the destruction of the tertiary structure of
the enzyme which is a key to their activity as catalysts.
Energy is also consumed in the centrifugation at different stages at ~10,000 to
15,000 g for periods of 10 and 15 min at low temperatures ~4 °C. Therefore, energy
is required for cooling of the system. Cooling is usually achieved using electricity
in refrigerated centrifuges. The environmental impact of both centrifugation and
cooling energy consumption depends on the source of electricity. This could be
hydroelectric, nuclear, gas, solar, etc.
11.7.6 Solid Waste Generated
While up to 60% of fish is eaten as food, the rest of it either goes to waste or
used in lower value applications such as fish meal, pet food, fertilizers and fish oil.
Production of enzymes from the solid waste generated from fish significantly boosts
the value chain. Enzymes have a much broader application in industry compared to
the former, and adding this to the value chain of the fish food industry can contribute
revenue which could compensate for the cost of production of other products from
the fish waste such as production of chitin from the fish scales (chitin is discussed
251
of 1:10 as a minimal used in similar extraction processes, we can estimate that a
minimum of 20 ml of water is used in the extraction of enzyme from 1 g of algae.
11.7.4 Use of Salts and Buffers
Where ammonium sulfate is used, this eventually breaks down into nitrogen, hydrogen and sulfate which can be taken up by plants and other organisms if adequately
disposed of. Unlike other more intensive processes such as the extraction of chitin
from crustacean shells or extraction of collagen from animal tissue which makes use
of strong acids and alkali, enzyme extraction is relatively milder and requires use of
milder chemicals.
11.7.5 Energy Consumption
The homogenization of the algae biomass into powdered form achieves improved
release of the proteins into water as a result of reduced particle size and mechanical disruption, and this process requires significant amounts of energy. Drying of
the samples prior to homogenizing reduces the amount of energy consumed in this
process. The quantity of energy consumed at this stage varies depending on the
machinery used and the efficiency.
The drying process is done at ambient conditions; high-temperature oven-drying
is not an option here as this will result in the destruction of the tertiary structure of
the enzyme which is a key to their activity as catalysts.
Energy is also consumed in the centrifugation at different stages at ~10,000 to
15,000 g for periods of 10 and 15 min at low temperatures ~4 °C. Therefore, energy
is required for cooling of the system. Cooling is usually achieved using electricity
in refrigerated centrifuges. The environmental impact of both centrifugation and
cooling energy consumption depends on the source of electricity. This could be
hydroelectric, nuclear, gas, solar, etc.
11.7.6 Solid Waste Generated
While up to 60% of fish is eaten as food, the rest of it either goes to waste or
used in lower value applications such as fish meal, pet food, fertilizers and fish oil.
Production of enzymes from the solid waste generated from fish significantly boosts
the value chain. Enzymes have a much broader application in industry compared to
the former, and adding this to the value chain of the fish food industry can contribute
revenue which could compensate for the cost of production of other products from
the fish waste such as production of chitin from the fish scales (chitin is discussed