产氢菌的复合诱变选育及突变株HCM-23的产氢特性

Combined Mutation Breeding of H2-producing Strain and Hydrogen Producing Characterization of a H2-producing Mutant HCM-23

摘要:

以厌氧产氢细菌Clostridium sp. H-61为原始菌株, 先后经亚硝基胍(NTG)、紫外(UV)诱变, 选育得到1株高产突变株HCM-23。在葡萄糖浓度为10 g/L的条件下, 其产氢量为3024 mL/L, 比原始菌株提高了69.89%; 其最大产氢速率为33.19 mmol H2/g DW·h, 比原始菌株(19.74 mmol H2/g DW·h)提高了68.14%。经过多次传代试验, 稳定性良好。其发酵末端产物以乙醇和乙酸为主, 属于典型乙醇型发酵代谢类型。其最适产氢初始pH为6.5, 最适生长温度为36℃, 以蔗糖为最佳碳源。与原始菌株相比, 突变株HCM-23的产氢特性发生了改变, 如生长延滞期延长, 可利用无机氮源等。

Abstract:

The fermentative H2-producing strain Clostridium sp. H-61 was isolated from anaerobic sludge, was used as an original strain which was induced by NTG and UV for increasing and the hydrogen production ability. One of the highest efficient H2-producing mutants was named as HCM-23 with its stable hydrogen production ability. which was measured in the batch culture experiments. With the condition of 10 g/L glucose, its cumulative hydrogen yield and hydrogen production rate was 3024 mL/L and 33.19 mmol H2/g DW·h, 69.89% and 68.14% higher than that of the original strain, respectively. The terminal liquid product compositions showed that the mutant HCM-23 fermentation was ethanol type, while the original strain H-61 fermentation was butyric acid type. Varieties of parameters of hydrogen production fermentation studied, including time, carbon source, nitrogen source, glucose concentration, glucose utilization, initial pH and incubation temperature had been studied, indicated the optimum condition of hydrogen production for the mutant HCM-23 as initial pH 6.5, temperature 36℃, and the favorite substrate was sucrose. The hydrogen production characters of the mutant and the original strain were different, such as, the growth lag phase and the utilization of inorganic nitrogen source, etc. This work shows a good application potential of NTG-UV combined mutation in the biohydrogen production. And the hydrogen production mechanism and metabolic pathway should be explored furthermore.