营养盐输入方式对3种微藻生长及种间竞争的影响

Effect of Different Nutrient Input Modes on the Growth and Interspecific Competition of Three Microalgal Species

在不同的营养盐输入方式下(一次性输入、每2d输入、每5d输入)对杜氏盐藻(Dunaliella salina)、三角褐指藻(Phaeodactylum tricornutum)和米氏凯伦藻(Karenia mikimotoi)进行单种培养和混合培养,研究不同的营养盐输入方式对这3种海洋微藻生长及种间竞争的影响。结果表明:单种培养时,盐藻在一次性输入方式下的最终细胞密度和平均比生长速率均显著大于其它2种输入方式;三角褐指藻和米氏凯伦藻在每5d输入方式下的最终细胞密度显著大于其它2种输入方式。混合培养时,盐藻在一次性输入方式下的最终细胞密度和平均比生长速率均显著大于其它2种输入方式,最终细胞密度占总细胞密度的47.3%;三角褐指藻在一次性输入方式下的最终细胞密度和平均比生长速率均显著小于每2d输入和每5d输入方式,后2个处理组的最终细胞密度分别占总细胞密度的90.3%和79.9%;在3种输入方式下米氏凯伦藻的最终细胞密度及占总细胞密度的百分比、平均比生长速率均显著小于其它2种微藻。研究表明,无论单种培养还是混合培养,营养盐一次性输入方式均能促进盐藻的生长,而脉冲输入方式能促进三角褐指藻的生长。脉冲输入方式下混合培养时,三角褐指藻在种群中占优势。

In this study, three microalgal species （Dunaliella salina, Phaeodactylurn tricornuturn and Karenia mikimotoi） were cultured in different nutrients input modes （input one time, input every 2 days and input every 5 days） in monoculture and mixed culture in order to study the effect of nutrients input modes on the growth and interspecific competition of these microalgal species. When three microalgae were cultured in monoculture, the final cell density and average specific growth rate of D. salina of in- put one time mode were significantly higher than those of input every 2 days and input every 5 days mode; and the final cell density of P. tricornutum and K. mikimotoi of input every 5 days mode were significantly higher than those of input one time and input every 2 days mode. When these microalgae were co-cultured, the final cell density which accounted for 47. 3 ~./00 of the total and the average specific growth rate of D. salina were significantly higher than those of other two modes; and the final cell den- sity and the average specific growth rate of P. tricornuturn of input one time mode were significantly lower than those of input every 2 days and input every 5 days mode, in which the final cell density ac- counted for 90. 3% and 79. 9~//00 of the total, respectively; the final cell densities, the percentages of the total cell density and the average specific growth rate of K. rnikirnotoi of all three modes were signifi- cantly lower than those of other two microalgae. The results indicated that the growth of D. salina may be promoted by one time input mode while that of P. tricornuturn may be promoted by pulse input modes under monoculture or mixed culture condition. The P. tricornuturn of pulse input modes was dominant in mixed culture.