RESUMO
Cooperation hydrogen production was carried out using Rhodopseudomonas sp. DT and Enterobacter aerogenes. The effects of the initial ratio of Rhodopseudomonas sp. DT and E. aerogenes, culture temperature, and carbon source on the cooperation hydrogen production were investigated. The results suggested that cooperation hydrogen production rate was highly affected by the initial ratio of Rhodopseudomonas sp. DT and E. aerogenes. The mixed bacteria of Rhodopseudomonas sp. DT and E. aerogenes with 1:1 initial ratio benefited to the cooperation hydrogen production, which led the hydrogen production rate and duration of gas production to 3.1 mol H2/mol glucose and 81 h, respectively. The pH dynamics analysis of culture medium further discovered that the pH of the mixed bacteria with 1:1 initial ratio changed from 6 to 7 smaller than other conditions, which was probably fitted to produce hydrogen. Furthermore, the mixed bacteria with 1:1 initial ratio had the higher hydrogen production efficiency at temperatures of 28?C and 37?C than at 20?C, and without any hydrogen production at temperature of 50?C. The carbon sources of glucose, succinate acid, malic acid could be used to produce hydrogen by the mixed bacteria. Even the soluble starch, unused by Rhodopseudomonas sp. DT, was also decomposed by the mixed bacteria to produce hydrogen with the conversion efficiency of 8.22%. The glucose was the optimal carbon resource, and the conversion efficiency could reach to 36.11%. The results, further, implied that the cooperation hydrogen production could enlarge the use of the carbon sources.