Photobioreactors
125
First attempts of mass cultivation were made in Germany during World
War 2 when they tried to produce liquid fuel from Diatomeae. In the early
1950s, this led to efforts to convert waste carbon dioxide produced in the Rhine
industrial zone to Scenedesmus and Chlorella biomass. The Soeder group in
particular, and the summarizing works performed in the Carnegie Institute in
Washington have laid the foundation for large-cale cultivation of phototrophic
organisms as practiced today [4, 5].
In the following period, highly active centres were established, mainly in East
Europe (Czechoslovakia, U.S.S.R., Bulgaria) and in Israel. In the middle of
the 1970s, Chlorella was produced commercially in Japan for the first time. The
philosophy on health food in Asia might have been decisive for accepting the
relatively high price. The U.S. company Earthrise made one of the first attempts
to establish algal production in the West. Today, the market is dominated by the
filamentous blue-green alga of the genus Spirulina which was historically collected
by the native population around the Chad lake and at Lake Texcoco. Due to the
high protein and vitamin content, Spirulina is still used as meat supplement [6].
In the U.S.A. in the 1950s, algae were already involved in environmental
technologies. The quality of waste waters could be improved significantly by the
mass cultivation of phototrophic microorganisms. The resulting biomass was
fermented to methane at a conversion rate of 50-70%. This process was subject
to much interest during energy crises [7]. Beside environmental large scale
cultivation, Oswald and coworkers also created the idea to utilize microalgae for
the development of bioregenerative life-support systems [8]. Today, systems for
spacecraft [9] and bioreactors are available, and may be used for air regeneration in submarines [10].
The still important field of aquaculture was opened in the early 1970s, when
the large-scale cultivation of phytoplankton in a mixture of waste water and salt
water was established. The yielded plankton mass was fed to marine bivalves
and other freshwater organisms [11].
Despite first attempts of large-scale production of valuable substances from
microalgae, e.g. production of E-carotene from Dunaliella in the Australian HuttLagoon or in the Negev desert in Israel, it is only recently that much attention was
paid to microalgae as a source for the production of fine chemicals [12, 13].
Table 1 gives a short market analysis of a multitude of valuable substances
from microalgal biomass of economic and scientific interest [14].
The chemical and pharmaceutical industry is interested principally in
products such as
- natural colours (carotenoids, phycobiliproteins),
- vitamins (tocopherols etc.),
- polysaccharides with immunomodulatory properties,
- fatty acids (polyunsaturated, e.g. eicosapentaenic acid).
However, there is a lack of cultivation systems which allow for high biomass
concentrations for economic production of valuable substances with respect to
sterile conditions.
125
First attempts of mass cultivation were made in Germany during World
War 2 when they tried to produce liquid fuel from Diatomeae. In the early
1950s, this led to efforts to convert waste carbon dioxide produced in the Rhine
industrial zone to Scenedesmus and Chlorella biomass. The Soeder group in
particular, and the summarizing works performed in the Carnegie Institute in
Washington have laid the foundation for large-cale cultivation of phototrophic
organisms as practiced today [4, 5].
In the following period, highly active centres were established, mainly in East
Europe (Czechoslovakia, U.S.S.R., Bulgaria) and in Israel. In the middle of
the 1970s, Chlorella was produced commercially in Japan for the first time. The
philosophy on health food in Asia might have been decisive for accepting the
relatively high price. The U.S. company Earthrise made one of the first attempts
to establish algal production in the West. Today, the market is dominated by the
filamentous blue-green alga of the genus Spirulina which was historically collected
by the native population around the Chad lake and at Lake Texcoco. Due to the
high protein and vitamin content, Spirulina is still used as meat supplement [6].
In the U.S.A. in the 1950s, algae were already involved in environmental
technologies. The quality of waste waters could be improved significantly by the
mass cultivation of phototrophic microorganisms. The resulting biomass was
fermented to methane at a conversion rate of 50-70%. This process was subject
to much interest during energy crises [7]. Beside environmental large scale
cultivation, Oswald and coworkers also created the idea to utilize microalgae for
the development of bioregenerative life-support systems [8]. Today, systems for
spacecraft [9] and bioreactors are available, and may be used for air regeneration in submarines [10].
The still important field of aquaculture was opened in the early 1970s, when
the large-scale cultivation of phytoplankton in a mixture of waste water and salt
water was established. The yielded plankton mass was fed to marine bivalves
and other freshwater organisms [11].
Despite first attempts of large-scale production of valuable substances from
microalgae, e.g. production of E-carotene from Dunaliella in the Australian HuttLagoon or in the Negev desert in Israel, it is only recently that much attention was
paid to microalgae as a source for the production of fine chemicals [12, 13].
Table 1 gives a short market analysis of a multitude of valuable substances
from microalgal biomass of economic and scientific interest [14].
The chemical and pharmaceutical industry is interested principally in
products such as
- natural colours (carotenoids, phycobiliproteins),
- vitamins (tocopherols etc.),
- polysaccharides with immunomodulatory properties,
- fatty acids (polyunsaturated, e.g. eicosapentaenic acid).
However, there is a lack of cultivation systems which allow for high biomass
concentrations for economic production of valuable substances with respect to
sterile conditions.