Effects of toxic dinoflagellate Alexandrium tamarense on two unicellular algae
本文研究了塔玛亚历山大藻(ATCI01品系)细胞再悬浮液、细胞破碎液、上清液、藻壳液、过滤液对亚心形扁藻悬浮性的影响,以及塔玛亚历山大藻与亚心形扁藻和小球藻之间的相互作用.结果发现,含有塔玛亚历山大藻成分的实验溶液均能在短时间内造成亚心形扁藻失去鞭毛形成胞囊而下沉,其中再悬浮液的影响最大.但亚心形扁藻受到的这种不利影响,一般在一周后即开始恢复.小球藻生长几乎不受塔玛亚历山大藻的影响,混合培养水体中的小球藻生长曲线与单种培养的几乎一致,其悬浮性也无明显改变.与亚心形扁藻进行混合培养的塔玛亚历山大藻(ATCI01品系和ATHK品系)均表现出培养前期增殖曲线与单种培养类似,但在一周后混合培养的塔玛亚历山大藻的增殖曲线开始下降,这一时间恰好与扁藻细胞密度开始增加的时间相一致.而与小球藻的混合培养的塔玛亚历山大藻在培养前期与单种培养一致,后期则种群数量有所下降.The effects of a toxic dinoflagellate, Alexandrium tamarense (strain ATCI01) on the suspension of Platymonas subcordiformis with its re-suspended cells, broken cells, cell contents, cellular fragments and free-cell medium were investigated, and the interaction in the growth between Alexandrium tamarense and Platymonas subcordiformis or Chlorella sp. was also studied. The results showed that cells of Platymonas subcordiformis cultured in the various treatments above-mentioned lost the flagellums, formed cystsand settled on the bottom of the flasks in short time, and the most obvious effect was observed in the re-suspended cells. However, the negative impact lasted onlya few days, and the cells of Platymonas subcordiformis recovered after a week. There was no obvious change in the growth curves for the suspension of Chlorella sp. whether it was in uni-culture or mixed-culture with Alexandriumtamarense. Moreover, the growth curves of ATCI01 and ATHK in uni-culture or (mixed-culture) with (Platymonas) (subcordiformis) were similar in prophase, but the curves of A. tamarense in mixed-culture declined a week later when the cell density of P.subcordiformis increased gradually. The same phenomina occurred in the A.tamarense culture mixed with Chlorella sp.