Three kinds of photosynthetic bacteria (PSB for short, including Rhodobacter sphaeroides H strain,Rhodopseudomonas palustris N strain, and Rhodospirillium rubrum M strain), Bacillus subtilis (BS) and Lactobacillus plantarum (LP), which have the functions of repairing multiple heavy metal pollution in the soil and preventing, controlling diseases, and insect pests, were mixed-cultivated. The medium formula and culture conditions were optimized by single-factor and response surface tests. The results showed that the optimal conditions for the mixed-culture of bacteria were as follows: photosynthetic bacteria culture medium as the basic medium with additional 10 g/L sucrose as carbon source, 1.25 g/L ammonium sulfate as nitrogen source, culture at 31.5 ℃, initial pH 7.1, inoculation volume was equal to the initial cultured bacteria content after inoculation 1.90×109 cfu/mL, and culture for 28.0 h. Additive model method, the modified Gompertz equation, and analysis of growth characteristics of mixed-culture of functional bacteria showed all growth relationship of photosynthetic bacteria, Bacillus subtilis, and Lactobacillus plantarum were mutual beneficial. |