Characteristics Of Phosphorus Storage In Typical Algae With Different Growth Strategies

As a restrictive nutrient for life, phosphorus took widly part in many important physiological activities, such as cell division and protein synthesis. The phenomenon of phosphorus luxury adsorption appeared in many algae, they could made phosphorus stored as the form of polyphosphate(“Poly P” for short) in cell. The mechanism of phosphorus storage could be much clear by the research in the synthesis and decomposition of polyphosphates in the algae.In this paper, several detection methods of Poly P in typical algae with different growth strategies were optimized; further more, phosphorus storage characters of several typical algae were discussed.In this paper, hot-water extraction, one kind of chemical analysis methods for detection of Poly P granules in algae was founded. It was quite easy to operate. The optimal extraction temperature was made sure for algae living on different growth strategies. At the same time, fluorescence staining technology was applied in the analysis of Poly P. In this method, Poly P stained by 2-(4-amidinophenyl)-indole-6-carboxamidine dihydrochloride(DAPI) could appear yellow fluorescence when stimulated by UV. The content of DAPI was confirmed by a preexperiment. According to the result, some conclusions came as follows:① When hot-water extraction method was applied in the detection of Poly P granules in different kind of algae living on different growth strategies, the optimal extraction temperature was different among them. The best extraction temperature for Aphanizomenon flos-aquae was 105℃, while it was 95℃ for Chlorella sp. and 125℃ for Cyclotella sp. At the same time, for these algae living in their stationary phases and cultured in the lab, the Poly P granules content in the TCP was also different from each other, it was the biggest in Aphanizomenon flos-aquae, which was 57.2%; Chlorella sp. ranked at the last by 37.2%; while Cyclotella sp. was in the middle by 53.7%.② The existential state of Poly P in algae could be distinguished by fluorescence staining technology. When DAPI was used in the method, the best content of DAPI was 50mg/L.On the other hand, algae living on different growth strategies were cultured by chemostat to obtain algae living at different growth rates. These typical algae were Chlorella sp., Microcystis flos-aquae, Anabaena flos-aquae and Aphanizomenon flos-aquae. The growth rates were 0.1 、 0.2 、 0.4 、 0.6 、 0.8d-1. In this way, the physiological index and phosphorus storage capacity were discussed. According to the result, some conclusions came as follows:① Chemostat could well simulate the growth of algae under different growth rates. When the algae were cultured in different dilution rates, all four kinds of algae could achieve the stationary phases and they kept good activity. Biomass was quite low when chemostat achieve the stationary phases at high dilution rates.② For algae living at different growth rates, content of cell C, cell N were different among them, as well as C/N(mole ratio). Cell C and cell N showed a increasing trend when growth rate was increased. Cell C and cell N of Anabaena flos-aquae(strategy CS) was the biggest in these four algae. C/N(mole ratio) was quite stable in Anabaena flos-aquae and Aphanizomenon flos-aquae(strategy CS) among all growth rates. C/N(mole ratio) appeared an inflection point at 0.6d-1 when the algae were Chlorella sp.(strategy C) and Microcystis flos-aquae(strategy S).③ Content of Poly P granules showed a increasing trend when growth rate was increased. Poly P granules in Aphanizomenon flos-aquae was little than other three algae at almost all five growth rates. While the amount in Anabaena flos-aquae was quite high. Amount of Poly P granules in Chlorella sp. was between Microcystis flos-aquae and Aphanizomenon flos-aquae. According to the fluorescence staining analysis, Poly P granules existed obviously in Anabaena flos-aquae and Aphanizomenon flos-aquae no matter which growth rate did algae live at. Poly P granules were just obvious at high growth rates for Chlorella sp. and Microcystis flos-aquae, while it was soluble Poly P that appeared obviously at low growth rates.④ The Droop model was applied to predict the minimal content of phosphorus in algae. The minimal content of Aphanizomenon flos-aquae was 0.06pg/cell, it was 0.09, 0.13, 0.16pg/cell for Chlorella sp., Microcystis flos-aquae and Anabaena flos-aquae,respectively.This paper built some technological foundations for detection and description of Poly P in different kind of algae, and made several theory basis for prediction of dominate alge.