For drying, a spray dryer is used. An atomizer is used to spray a mist of
Chlorella concentrate in the dryer tower, and moisture is removed instantaneously
with a wind of around 180 °C. The short heating time results in a low level of
change in the drying process. Leaf bodies obtained in this way serve as raw
materials for various products using Chlorella (Maruyama and Ando 1992).
7.4 Biotechnology of Microalgae
Because microalgae have long been used for biochemistry research and as feed for
parent and offspring fish and shellfish, culturing techniques have been established
for many types. Their relatively fast growth and ease of genetic manipulation are
raising hopes for their application in production of useful materials and addressing
global environment issues. Research to date, however, has been confined to production of mutant strains, genetic manipulation, and fixation for a relative few
microalgae (Ng, Daphe H. P. et al., 2015).
7.4.1 Mutant Strain Production
Mutants are sometimes used to obtain strains containing particular useful substances. Mutations are produced through contact with mutagens or exposure to
ultraviolet rays, X-rays, and gamma rays and subjected to selective treatment to
create mutant strains. Examples obtained to date include resistant mutants; auxotrophic mutants; temperature- and ultraviolet-sensitive mutants; mutants with
photosynthesis, nitrogen fixing, or carbon metabolism defects; and morphological
mutants (Kao et al. 2012).
Among blue-green algae, single-celled Anacystis nidulans (Synechococcus) and
multi-celled Anabaena variabilis are the most commonly used. Mutant production
has also been attempted with Agmenelum quadruplicatum, Synecocystis, Synechococcus cedrorum, Aphanocapsa, Gloeocapsa alpicola, Aphanothece halophytica, Nostoc muscorum, and Spirulina platensis.
Chlamyodomonas species—C. reinhardtii in particular—are most commonly
used among green algae. Some research has also been conducted with Chlorella,
Scenedesmus, and Euglena.
7.4.2 Genetic Manipulation
Prokaryotes such as brown algae and eukaryotes such as green algae have a number
of basic differences that affect genetic manipulation. Prokaryotes are haploid,
whereas eukaryotes have haploid and diploid generations. In prokaryotes, there is
no interaction with the organelle genome within individual genes, while mitochondrion and chloroplast genomes in eukaryotes interact with the nuclear genome.
7.3 Mass-Production of Microalgae
211
Chlorella concentrate in the dryer tower, and moisture is removed instantaneously
with a wind of around 180 °C. The short heating time results in a low level of
change in the drying process. Leaf bodies obtained in this way serve as raw
materials for various products using Chlorella (Maruyama and Ando 1992).
7.4 Biotechnology of Microalgae
Because microalgae have long been used for biochemistry research and as feed for
parent and offspring fish and shellfish, culturing techniques have been established
for many types. Their relatively fast growth and ease of genetic manipulation are
raising hopes for their application in production of useful materials and addressing
global environment issues. Research to date, however, has been confined to production of mutant strains, genetic manipulation, and fixation for a relative few
microalgae (Ng, Daphe H. P. et al., 2015).
7.4.1 Mutant Strain Production
Mutants are sometimes used to obtain strains containing particular useful substances. Mutations are produced through contact with mutagens or exposure to
ultraviolet rays, X-rays, and gamma rays and subjected to selective treatment to
create mutant strains. Examples obtained to date include resistant mutants; auxotrophic mutants; temperature- and ultraviolet-sensitive mutants; mutants with
photosynthesis, nitrogen fixing, or carbon metabolism defects; and morphological
mutants (Kao et al. 2012).
Among blue-green algae, single-celled Anacystis nidulans (Synechococcus) and
multi-celled Anabaena variabilis are the most commonly used. Mutant production
has also been attempted with Agmenelum quadruplicatum, Synecocystis, Synechococcus cedrorum, Aphanocapsa, Gloeocapsa alpicola, Aphanothece halophytica, Nostoc muscorum, and Spirulina platensis.
Chlamyodomonas species—C. reinhardtii in particular—are most commonly
used among green algae. Some research has also been conducted with Chlorella,
Scenedesmus, and Euglena.
7.4.2 Genetic Manipulation
Prokaryotes such as brown algae and eukaryotes such as green algae have a number
of basic differences that affect genetic manipulation. Prokaryotes are haploid,
whereas eukaryotes have haploid and diploid generations. In prokaryotes, there is
no interaction with the organelle genome within individual genes, while mitochondrion and chloroplast genomes in eukaryotes interact with the nuclear genome.
7.3 Mass-Production of Microalgae
211