ABSTRACT
Algae have been long recognized as a heterogeneous group of organisms, ranging from prokaryotic blue greens to distantly related eukaryotic lines. Their growth modes range from phototrophy through photoheterotrophy to heterotrophy. Each growth mode in turn can be either obligate or facultative (1). The genetic diversity of microalgae is evident still further in their ecological diversity and ubiquitous distribution. Different species can grow in water ranging from fresh water to hypersaline environments; from the water surface to the limits of photic zone, which is often 200-300 meters; either free floating or attached (2).
