Enhancing lipid production in microalgae Chlorella PY-ZU1 with phosphorus excess and nitrogen starvation under 15% CO2 in a continuous two-step cultivation process

•A domesticated microalgae was studied in a continuous two-stage cultivation process with 15% CO2.•Biomass and lipid productivity were promoted in the second stage with adequate phosphorus.•The contents and distribution of many phosphorus compounds, especially polyphosphate and pyrophosphate, were analyzed.•Several proteins related to energy supply and carbon fixation were found to be up-regulated.