Effect of nitrogen on fatty acids composition of Nostoc commune

Nostoc commune cultivated in two different conditions (with or without nitrogen in medium) were analyzed for their fatty acids composition using a modified Bligh-Dyer method and GC-MS. The results indicated that C16 and C18 were dominant compositions of total fatty acids (TFAs) , among which the contents of unsaturated fatty acids (UFAs) were all above 50% in all tested samples. TFAs concentration of N. commune cultivated in medium without nitrogen (BG110) was 13.29mg/g, while that of saturated fatty acids (SFAs) and UFAs were present at 36.91%, 63.09% respectively. C18：1 was present at 15.99% in particular;TFAs concentration of N. commune cultivated in medium with nitrogen (BG11) was 7.72mg/g, while concentrations of SFAs and UFAs were present at 47.91%, 52.09% respectively. C18∶1 was 1.74%. The present study showed that the contents of TFAs especially UFAs was significantly (p<0.05) higher in BG110 group than in BG11 group. This demonstrated that the absence of nitrogen was propitious to the accumulation of fatty acids especially UFAs.