Phosphorus is an essential element for life on earth and is also important for modern agriculture, which is dependent on inorganic fertilizers from phosphate rock. Polyphosphate is a biological polymer of phosphate residues, which is accumulated in organisms during the biological wastewater treatment process to enhance biological phosphorus removal. Here, we investigated the relationship between polyphosphate accumulation and electron-dense bodies in the green alga Parachlorella kessleri. Under sulfur-depleted conditions, in which some symporter genes were upregulated, while others were downregulated, total phosphate accumulation increased in the early stage of culture compared to that under sulfur-replete conditions. The P signal was detected only in dense bodies by energy dispersive X-ray analysis. Transmission electron microscopy revealed marked ultrastructural variations in dense bodies with and without polyphosphate. Our findings suggest that the dense body is a site of polyphosphate accumulation, and P. kessleri has potential as a phosphate-accumulating organism.

• MeSH
• Staining and Labeling MeSH
• Models, Biological MeSH
• Chlorophyta cytology   growth & development   metabolism   ultrastructure   MeSH
• Electrons * MeSH
• Phosphates metabolism   MeSH
• Lipids chemistry   MeSH
• Polyphosphates metabolism   MeSH
• Sequence Analysis, RNA MeSH
• Sulfur metabolism   MeSH
• Transcriptome genetics   MeSH
• Imaging, Three-Dimensional MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Phosphates MeSH
• Lipids MeSH
• Polyphosphates MeSH
• Sulfur MeSH