Abstract: The growth characteristics and the effects of glucose, light and pH on the growth of Microcystis viridis(A. Br.) Lemm. under mixotrophic conditions have been investigated. The results showed that by comparison, the mixotrophic growth rate was much higher than the photoautotrophic and the exponential phase elongated in the mixotrophic culture. Under same condition, it was evident that the mixotrophic culture of Microcystis viridis produced much biomass than that of the photoautotrophic culture; Under same light intensity, with initial glucose concentrations in the range from 0 to 18.0g/l, higher glucose concentrations favored cell growth more markedly, whereas the concentrations above 18g/l presented only limited improvement on cell growth; Under same initial glucose concentrations, the growth rate and biomass/glucose yield increased with light intensity, ranging from 24 to 112μE·m^-2·s^-1; When light intensity was higher than 112μE·m^-2·s^-1, The range of the growth rate lower Microcystis viridis appeared light saturation. When pH ranging from 8.0 to 10.0, Microcystis viridis growth was promoted obviously; but more deviating from that, more restraining Microcystis viridis growth, even leading to death.

Key words: Microcystis viridis, mixotrophic, glucose, light intensity, pH