Nitrogen source is one of the important factors that affect the microalgae growth and lipid accumulation. We studied the effects of various nitrogen sources (i.e. NaNO3, CO(NH2)2, NH4Cl and CH3COONH4) and amount on the growth density, lipid yield, and eicosapentaenoic acid (EPA) content of Nannochloropsis oculata by single factor experimental method. The results show that N. oculata preferred NH4+ as nitrogen source rather than NO3- and CO(NH2)2. NH4+ could promote the growth and lipid accumulation of N. oculata. With the increase of nitrogen concentration, the biomass and the content of polyunsaturated fatty acid (PUFA) increased, but the content of lipid decreased. CH3COONH4 was the most suitable for growth, accumulation of lipid and EPA of N. oculata among the four investigated nitrogen sources. The optimal concentration was 5.29 mmol/L.
Eicosapentaenoic Acid ; metabolism ; Lipids ; biosynthesis ; isolation & purification ; Microalgae ; growth & development ; metabolism ; Nitrogen ; analysis ; metabolism ; Stramenopiles ; growth & development ; metabolism

Objective: To explore the correlation between menopausal hormone therapy（MHT）and breast lesions in perimenopausal women,and to provide evidence for safe use of MHT. Methods: The 40-60 year-old women who visited Hangzhou Women's Hospital and met the diagnostic criteria for perimenopausal syndrome were recruited. The intervention group received MHT and was divided into three subgroups according to the MHT regimen：estrogen-progesterone cycle therapy（A）,estrogen-progesterone continuous therapy（B）,estrogen therapy（C）. The control group did not receive MHT. All the patients received regular mammography to quantify and evaluate breast lesions. The generalized estimating equation was used to analyze the changes of breast lesions between different groups. Results: There were 80 cases in the intervention group,with 49 in group A,26 in group B,5 in group C,and 80 cases in the control group. After two years of follow-up,there was no statistically significant differences of time,group and interaction in breast density,volume of breast fibrous tissue and the volume of breast between three intervention groups and the control group（P>0.05）; there was no statistically significant differences of group and interaction in positive rate of calcification and breast mass between the intervention group and the control group（P>0.05）. Conclusion Receiving MHT intervention for two years did not increase the risk of breast lesions.