As an environmentally friendly and industrially useful biopolymer, poly--glutamic acid (-PGA) from Bacillus licheniformis CGMCC 2876 was characterized by the high-resolution mass spectrometry and H-1 NMR. A flocculating activity of 11,474.47 U mL(-1) obtained with -PGA, and the effects of carbon sources, ions, and chemical properties (D-/L-composition and molecular weight) on the production and flocculating activity of -PGA were discussed. Being a bioflocculant in the sugar refinery process, the color and turbidity of the sugarcane juice was IU 1,877.36 and IU 341.41 with 0.8 ppm of -PGA, respectively, which was as good as the most widely used chemically synthesized flocculant in the sugarcane industrypolyacrylamide with 1 ppm. The -PGA produced from B. licheniformis CGMCC 2876 could be a promising alternate of chemically synthesized flocculants in the sugarcane industry. (c) 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1287-1294, 2015