Bioaugmentation Anaerobic Digestion of Huangshui by Saccharomyces cerevisiae

Huangshui (HS) is rich in organic matter from Baijiu production. Anaerobic digestion (AD) of HS offers a hopeful strategy for efficient waste utilization and energy recovery. However, high organic load often causes low methane (CH4) yield and process instability. The aim of this study was to explore the mechanism of Saccharomyces cerevisiae (S. cerevisiae) to favor AD systems for more CH4. And the results revealed that with an inoculation at 8% (v/v) addition of S. cerevisiae, CH4 yield was 219.7 mL/g COD, representing a 20% increase compared to the control without S. cerevisiae. The main manifestation of augmentation was the increased bioavailability of dissolved organic compounds. In addition, the ethanol produced by S. cerevisiae under anaerobic conditions served as an electron donor to supply metabolic intermediates supporting methanogenesis, enriching Bacteroidetes_vadinHA17, Longilinea and Methanosaeta. This strategy promoted organic matter degradation and increased CH4 yield, favoring the efforts of the industry to reduce pollution and carbon emissions.