Abstract: 8 strains of photosynthetic bacteria Rhodopseudomonas were used to study the effect of bacterial initial activity, illumination intensity, carbon sources, strain differences on their hydrogen production. The results show that different strains are differed significantly in carbon source utilization,but they can utilize sodium lactate very well. Bacteria initial activity affects hydrogen production to a certain extent,and the hydrogen production activity of the bacteria is slightly higher in its stable growth phase than that in exponential growth phase.Illumination intensity has a significant influence on hydrogen production. Higher illumination intensity leads to higher hydrogen production rate.Strain B₂₁ of Rhodopseudomonas isolated from organically polluted areas of Shanghai has a very high hydrogen production rate, being 14.7ml·h^-1 ·g^-1 (dry cell) with the carbon source of sodium lactate (50 mmol·L^-1), nitrogen source of sodium glutamate (10 mmol·L^-1), illumination intensity of 6000 lux, and the temperature of 30℃.

Key words: Photosynthetic bacteria, Hydrogen production, Affecting factor, species distribution models, Southwest China, geographic distribution, Gentiana rhodantha, climate change