Optimization of Dilute Alkali Extraction of Crude Polysaccharides from Mixotrophic Chlorella sp.-XJY

摘要

Chlorella sp.-XJY isolated from the Ili River in Northern Xinjiang was cultivated under mixotrophic conditions. The maximum biomass and crude polysaccharide production significantly increased (2.06 g/L and 145.5 mg/L, respectively) under mixotrophic conditions than under photoautotrophic conditions. Dilute alkaline was employed to extract crude polysaccharides from Chlorella sp.-XJY. The effects of time, temperature, and pH value on extraction yield were investigated using response surface methodology. The optimal conditions were determined as follows: 3.2 h extraction time, 96.4 ℃ extraction temperature, and pH 10.94. Analysis of variance showed that the contribution of the quadratic model was significant (R~2 = 0.9808) for the responses. Under the optimum conditions, the extraction yield of crude polysaccharides was 10.56%, which matches well with the predicted yield of 10.72%.