Generalities
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1.1.2.2. Different groups of microalgae
There are two main groups of microalgae:
 Eukaryotes: These are unicellular or multicellular organisms with a complex
structure containing a membrane-bound nucleus and several internal organelles.
 Prokaryotes: unicellular organisms also known as cyanobacteria. They are
considered prokaryotes due to the absence of a membrane-bound nucleus inside
their cells (Filali, 2012).
Table 2: Diversity of eukaryotic and prokaryotic microalgae, marine and freshwater (Sharma
& Rai, 2011).
1.1.3. Reproduction of microalgae
The life cycle of microalgae comprises two processes of sexual and/or asexual reproduction:
 Asexual reproduction: microalgae can reproduce either by scissiparity in
cyanophyceae and mitosis in eukaryotes, or by sporulation.
 Sexual reproduction: This is the least frequent and most random mode in which
reproduction is based on the interaction of male and female gametes (Gayral, 1975; in
Amirouche & Benachrine, 2012).
Domain
Class
Prokaryota
Cyanophyceae
Prochlorophyceae
Eukaryota
Bacillariophyceae
Charophyceae
Chrysophyceae
Chlorophyceae
Cryptophyceae
Dinophyceae
Euglenophceae
Glaucophyceae
Haptophyceae
Phaeophyceae
Rhodophyceae