Chlorophyceae display in general a higher concentration of C16:0
over C16:l(n-7), and abundant C18 fatty acids, as is the case of n-3
(ALA) and n-6 isomers (Table 3). This class is the only one for which
synthesis of C14:0, C22:6(n-3) and C20:5(n-3) was not observed at
all. The fatty acid composition of the various M-strains claimed to
belong to the species Scenedesmus obliquus showed a considerable
variability under similar growth conditions; genetic alterations — due
to the long term stress they had been exposed to in aquaculture
biofilters, probably account for these differences.