Effects of Fermentation Conditions on Hydrogen Production from Liquid Wastes Contained Several Sugars by Strain HN001

  • Akira Sano, Venture Business Laboratory, Yokohama National University, Japan
  • Student Yuiko Koga, Department of Environmental Sciences, Yokohama National University, Japan
  • Keigo Yasuda, Graduate School of Environment and Information Sciences, Yokohama National University, Japan
  • Hikari Tanaka, Graduate School of Environment and Information Sciences, Yokohama National University, Japan
  • Professor Shigeharu Tanisho, Department of Environmental Sciences, Yokohama National University, Japan

    • A strain HN001 is effective bacteria degrading substrates such as glucose, sucrose, fructose and so on. In this study, liquid wastes containing these sugars were used as samples and degraded by the bacterium at different fermentation conditions. The effects of these conditions on hydrogen production performance were investigated. Distinctive characteristics of fermentation were figured out for a lot of liquid wastes containing various minerals and nitrogen sources.
    A batch experiment (cultivation volume : 75 mL) was carried out in simple menthod. Dilution ratio was changed from 1 to 10 times. Yeast extract and casamino acid were added under the concentration of 0.5 or 1.0 g L-1. H2 production volume, soluble metabolite concentrations and optical density were measured by using gas displacement of NaOH solution, HPLC and absorption spectrometer, respectively. The optimal condition of dilution ratio, yeast extract concentration and casamino acid concentration differed according to variety of samples. There seemed to be differences among samples for the concentrations of sugars, minerals and nitrogen sources. Finally, a continuous experiment (cultivation volume : 0.5 L) was carried out by using jar fermenter for 5 days. The sugar concentration was adjusted to 22 g-glucose L-1. Temperature and pH of cultivation were kept constant at 37 °C and 6.0, respectively. HRT was controlled at 6.0 – 1.5 h. H2 production rate increased as HRT was higher. The maximum H2 production rate was 2.7 L-H2 L-culture-1 h-1.