Effect of microaerobic microbial pretreatment on anaerobic digestion of a lignocellulosic substrate under controlled pH conditions. (May 2021) - Xu, Haipeng
Graphical abstract: Highlights: Proteiniphilum and Rummeliibacillus were dominant during mirobial pretreatment. Pretreatment enhanced hydrolysis and acidogenesis of lignocellulose. Both pH and pretreatment time greatly affected methane yield. The highest methane yield was found at pH 8 and 12 h of pretreatment. Abstract: The effects of various microaeration strategies and process parameters on anaerobic digestion (AD) of lignocellulosic substrates have received increased attention; however, different results have been reported. To determine optimal conditions and clarify the mechanisms influencing this process, the effect of pretreatment of microaerobic microbial on corn stover decomposition and AD was investigated with real-time pH control. Fresh cow manure was chosen as the inoculum, as it has the strongest cellulose hydrolysis capacity under microaeration conditions. Microaeration microbial pretreatment effectively promoted the hydrolysis and acidogenesis of corn stover, and pH considerably affected total solid reduction, volatile fatty acid (VFA), and accumulation of soluble chemical oxygen demand (sCOD) patterns by shifting microbial communities. Different pH levels and pretreatment times led to positive and negative effects on methane yield. A 12-h pretreatment of substrate at pH 8 prior to AD increased the methane yield by 16.6% in comparison with the un-pretreated sample.