Differences in growth and alkaline phosphatase activity between Microcystis aeruginosa and Chlorella pyrenoidosa in response to media with different organic phosphorus

The growth of Microcystis aeruginosa and Chlorella pyrenoidosa in three dissolved organic phosphorus sources (glucose-1phosphate, adenosine triphosphate, cyclic-adenosine monophosphate) were studied in cultures separated by a dialysis membrane. Results showed that M. aeruginosa and C. pyrenoidosa could utilize those three forms of organic phosphorus, but their growth rates and cell abundances were low in comparison with those in the orthophosphate control. M. aeruginosa had a higher growth rate than C. pyrenoidosa in glucose-1-phosphate, and then became dominate in the separate cultures. In contrast, those two algal species didn’t show any significant differences in the growth rate and cell abundance in the medium with adenosine triphosphate and cyclicadenosine monophosphate. Alkaline phosphatase was an important enzyme for hydrolyzing glucose-1-phosphate, adenosine triphosphate and cyclic-adenosine monophosphate, the activity of which was positively correlated with the growth rate of algae. Considering the big proportion of glucose-1-phosphate in the Lake Taihu, the capability of M. aeruginosa to efficiently utilize this type of organic phosphorus source might be one of reason that why M. aeruginosa is the dominant species in this hyper-eutrophic lake.