【摘要】 在铁限制条件下,进行东海原甲藻分泌铁载体的动态研究。对藻类在富铁与缺铁条件下生长状况、生长过程中分泌铁载体的情况以及海藻接种量对铁载体分泌的影响进行了连续观测,结果表明:东海原甲藻在缺铁条件下生长状况远不如在富铁条件下;随着藻类的生长,分泌铁载体不断增多,达指数生长期时,其分泌量也达到了最大值,之后藻类的生长和铁载体分泌都呈现下降趋势;高接种量东海原甲藻能分泌较多的铁载体,并在较短时间到达峰值。更多还原

【Abstract】 Under iron-limited conditions,marine microorganisms are able to secrete low-molecular-weight,highly specific iron chelators termed siderophores.These compounds scavenge iron from protein complexes or insoluble hydroxides in the extracellular environment and transport it to the cell cytosol via a membrane-bound receptor protein in the microorganism.Iron is a necessary requirement in marine ecosystems.Therefore research on siderophores is very significant to interpretation of high nitrate low chlorophyll(HNLC) regions and iron hypothesis.However,it is not clear whether eukaryotic phytoplankton can produce the iron-specific chelating compounds.Therefore,a systematic investigation was carried out for siderophore secreted by P.donghaiense Lu under iron-limited conditions.Parameters studied included the growth of the algae in iron-added and iron-deficient medium,the secretion of siderophore during algae growth,and the effect of algae population inoculated on the siderophore production.Results showed that the algae growth rate in iron-deficient medium was slower than those in iron-rich medium.Under iron-limited conditions,the siderophore production increased along with algae growth.Maximum production was observed in the exponential growth period.Thereafter the rate of algae growth and siderophore secretion started to decrease.Furthermore,increasing algae populationt resulted in secreting more siderophore and shortening the time needed to reach maximum production.更多还原