Bioflocculant from Shinella albus was firstly used to harvest Chlorella vulgaris.
New type of bioflocculant was high thermal, pH stability and low molecular weight.
Triple bond and cumulated double bonds of bioflocculant contributed to flocculation.
Bioflocculant was sensitive to different algal temperatures and pH, and metal ions.
The efficiency of bioflocculant with Ca2+ was high after optimized through RSM.