不同氮磷营养条件对中肋骨条藻和球等鞭金藻生长及元素组成的影响OA北大核心CSTPCD

In this paper,two species of microalgae,Skeletonema costatum and Isochrysis galbana were cultured continuously for 15 days under three different nutritional conditions:Normal condition(f/2 medium),low N/P condition(nitrogen limitation)and high N/P condition(phosphorus limitation).During the culture process,the cell density,chlorophyll a concentration,element content(C,N,P)and stoichiometric ratio of algal cells and the content of inorganic salts in the culture medium were meas-ured.The effects of N/P imbalance and different algae species on the growth,elemental composition and nutrient utilization of marine microalgae were investigated.The results showed that:(1)nitrogen-limiting conditions promoted the proliferation of two microalgae,phosphorus-limiting conditions re-duced the proliferation of microalgae;nutrient imbalance was not conducive to the accumulation of Chlo-rophyll a in algal cells;(2)Under different N/P conditions,the two the C content of the algae changed little,the contents of N and P in the cells of the two algae decreased with time,and the content of N was the highest in the high N/P group.Different N/P conditions had a very significant effect on the con-tent of N in the cells;There was no significant difference in P content between the low N/P group and the high N/P group and the control group;Different algae species had significant effects on the contents of C and P elements in cells;(3)For Skeletonema costatum,the C/N value in high N/P group and low N/P group,the C/P value in low N/P group and the N/P value in high N/P group were all significantly different from the control group;For Isochrysis galbana,there was no significant difference in the ratios of various elements between the three conditions and the control group;Different N/P conditions only had a very significant effect on cell N/P value;(4)Nitrogen limitation increased the utilization of NO3--N,and phosphorus limitation decreased the utilization of NO3--N;however,these two nutrient imbalances have little effect on the utilization of PO43--P by algae cells.