The effect of physical and chemical factors on the flocculation of Zymomonas mobilis and the flocculation mechanism research

• 1、School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240

Abstract：The effect of 20 kinds of physical and chemical factors on the flocculation of Zymomonas mobilis ZM401 has been studied in this work. The results showed that: the flocculation material of ZM401 could be easily degraded in acid, but was stable in alkaline environment. Moreover, the flocculation was not sensitive to temperature. The addition of metal cations had no obvious effect on the flocculation, only with the increasing of Mg2+, the flocculation efficiency had a slightly increasing by 2.9%. Monosaccharide had little effect on the flocculation, while sucrose and cellobiose had postive effect on the flocculation efficiency. The addition of organic solvents increased the flocculation, and ethanol improved the flocculation efficiency by about 2.6%. The addition of the α-amylase, chitosanase, lipase and protease K almost had no influence on the flocculation while flocculation was very sensitive to cellulase, which with 0.15 FPU/mL caused the flocculation irreversible collapse. It is proved that the material related to flocculation of Zymomonas mobilis is cellulose, by which cell adhered to each other.

Keywords： Bioengineering Zymomonas mobilis Flocculation Physical and chemical factors Cellulose