Microbial Community Shifts during Biogas Production from Biowaste and/or Propionate

Bioengineering

Chaoran Li¹  Christoph Moertelmaier¹  Josef Winter¹  Claudia Gallert¹ 

[1] Institute of Biology for Engineers and Biotechnology of Wastewater, Karlsruhe Institute of Technology (KIT), Am Fasanengarten, Karlsruhe D-76128, Germany; E-Mails:

关键词: anaerobic co-digestion;    biowaste;    propionate;    propionate-oxidizing bacteria (POB);    methanogenic community;    community shifts;   

DOI  :  10.3390/bioengineering2010035

来源: mdpi

【 摘 要 】

Propionate is the most delicate intermediate during anaerobic digestion as its degradation is thermodynamically unfavorable. To determine its maximum possible degradation rates during anaerobic digestion, a reactor was fed Monday to Friday with an organic loading rate (OLR) of 12/14 kg COD_biowaste·m⁻³·d⁻¹ plus propionate up to a final OLR of 18 kg COD·m⁻³·d⁻¹. No feed was supplied on weekends as it was the case in full-scale. To maintain permanently high propionate oxidizing activity (POA), a basic OLR of 3 kg COD_propionate·m⁻³·d⁻¹ all week + 11 kg COD_biowaste·m⁻³·d⁻¹ from Monday to Friday was supplied. Finally a reactor was operated with an OLR of 12 kg COD_biowaste·m⁻³·d⁻¹ from Monday to Friday and 5 kg COD_propionate·m⁻³·d⁻¹ from Friday night to Monday morning to maintain a constant gas production for permanent operation of a gas engine. The propionate degradation rates (PDRs) were determined for biowaste + propionate feeding. Decreasing PDRs during starvation were analyzed. The POA was higher after propionate supply than after biowaste feeding and decreased faster during starvation of a propionate-fed rather than a biowaste-fed inoculum. Shifts of the propionate-oxidizing and methanogenic community were determined.

【 授权许可】

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