Biohydrogen and carboxylic acids production from wheat straw hydrolysate

Bioresour Technol. 2016 Sep:216:1093-7. doi: 10.1016/j.biortech.2016.05.119. Epub 2016 May 30.

Abstract

Hydrolyzed wheat straw was converted into carboxylic acids and biohydrogen using digesting bacteria. The fermentations were carried out using both free and membrane-encased thermophilic bacteria (55°C) at various OLRs (4.42-17.95g COD/L.d), in semi-continuous conditions using one or two bioreactors in a series. The highest production of biohydrogen and acetic acid was achieved at an OLR of 4.42g COD/L.d, whilst the highest lactic acid production occurred at an OLR of 9.33g COD/L.d. Furthermore, the bioreactor with both free and membrane-encased cells produced 60% more lactic acid compared to the conventional, free-cell bioreactor. In addition, an increase of 121% and 100% in the production of acetic and isobutyric acid, respectively, was achieved in the 2nd-stage bioreactor compared to the 1st-stage bioreactor.

Keywords: Biohydrogen; Carboxylic acids; Membrane-encased cells; Two-stage digestion; Wheat straw hydrolysate.

MeSH terms

  • Bioreactors / microbiology*
  • Carboxylic Acids* / analysis
  • Carboxylic Acids* / chemistry
  • Carboxylic Acids* / metabolism
  • Fermentation
  • Hydrogen* / analysis
  • Hydrogen* / chemistry
  • Hydrogen* / metabolism
  • Hydrolysis
  • Triticum* / chemistry
  • Triticum* / metabolism

Substances

  • Carboxylic Acids
  • Hydrogen