Metabolic Characters And Extended Culture Of Auto-Aggregative Hydrogen-Producing Bacterium

One of the key problems of industrial application of is how to increase the hydrogen producing efficiency. Addition of auto-aggregation hydrogen-producing will maintain the biomass and increase the hydrogen producing efficiency. Thus, research on aggregation mechanism of auto-aggregation hydrogen-producing and its continuous extended culture as assistant process of fermentive bio-hydrogen production technology will bring important practical value.Extracellular polymeric substances (EPS) of auto-aggregation and non- aggregation bacterium of Ethanoligenens harbinense were extracted by cation exchange resin, and aggregation mechanism was analysed. Bio-hydrogen progen production by pure culture and its extend culture of the strain of YUAN-3 were carried out by batch culture, fed-batch and continuous culture, and DGGE was used in monitoring the communities in continuous culture. The optimal conditions for extraction of EPS was resin addition of 30g/g-CDW, 400rpm, the extraction time was 12h. Compared with non-aggregation bacterium, EPS played important role in aggregation of YUAN-3, and in EPS, the content of protein, carbohydrates and DNA were 20.1±0.2mg/g-CDW, 67.5±0.8mg/g-CDW and 27.4±0.5mg/g-CDW, respectively.In different scale batch culture, YUAN-3 showed similar growth trends, though extended culture, YUAN-3 still kept higher growth and hydrogen-producing activity, the biomass was 0.33g/L, maximum specific hydrogen rate was 22.34mmol/(g-CDW·h), maximum hydrogen yield was 1.4molH₂/mol-glucose. The best time of adding bacterium to the bio-hydrogen production reactors was around 30 hours after cultured. In fed-batch culture, the best fed volum was 60% of the working volum, the best time was peak time of hydrogen production, in above conditions, YUAN-3 kept higher growth and hydrogen-producing activity.Contiuous culture would discharge fermention products, indraught the fresh medium, avoid restraint of fermention products. When YUAN-3 were continuous extended culture, the specific hydrogen rates were between 0.75mmolH₂/(g-CDW·h)⁵.60mmolH₂/(g-CDW·h), the hydrogen yield were between...