Improved Anaerobic Fermentation of Wheat Straw by Alkaline Pre-Treatment and Addition of Alkali-Tolerant Microorganisms

Bioengineering

Heike Sträuber¹  Franziska Bühligen²  Sabine Kleinsteuber²  Marcell Nikolausz²  Katharina Porsch² 

[1] UFZ—Helmholtz Centre for Environmental Research, Department of Environmental Microbiology, (in cooperation with) Deutsches Biomasseforschungszentrum (DBFZ), Permoserstr. 15, 04318 Leipzig, Germany;

关键词: lignocellulose;    hydrolysis;    volatile fatty acids;    T-RFLP fingerprinting;    Ca(OH)₂;    bioaugmentation;    BMP;    leach-bed reactor;    anaerobic digestion;    pre-treatment;   

DOI  :  10.3390/bioengineering2020066

来源: mdpi

【 摘 要 】

The potential of two alkali-tolerant, lignocellulolytic environmental enrichment cultures to improve the anaerobic fermentation of Ca(OH)₂-pre-treated wheat straw was studied. The biomethane potential of pre-treated straw was 36% higher than that of untreated straw. The bioaugmentation of pre-treated straw with the enrichment cultures did not enhance the methane yield, but accelerated the methane production during the first week. In acidogenic leach-bed fermenters, a 61% higher volatile fatty acid (VFA) production and a 112% higher gas production, mainly CO₂, were observed when pre-treated instead of untreated straw was used. With one of the two enrichment cultures as the inoculum, instead of the standard inoculum, the VFA production increased by an additional 36% and the gas production by an additional 110%, again mainly CO₂. Analysis of the microbial communities in the leach-bed processes revealed similar bacterial compositions in the fermenters with pre-treated straw, which developed independently of the used inoculum. It was suggested that the positive metabolic effects with the enrichment cultures observed in both systems were due to initial activities of the alkali-tolerant microorganisms tackling the alkaline conditions better than the standard inocula, whereas the latter dominated in the long term.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.