Enrichment and acclimation of an anaerobic mesophilic microorganism's inoculum for standardization of BMP assays

Appropriate enrichment of anaerobic microorganism's consortium is crucial for accurate biochemical methane potential (BMP) assays. An alternative method to produce and maintain a mesophilic methanogenic inoculum was demonstrated. Three sources of inoculum were mixed and acclimated for 857days in order to reach steady conditions (pH=7.90±0.46; VS/TS>50%; VFA/alkalinity=0.16±0.04gAcetic Acid/ [Formula: see text] ). Biogas yield >80% was obtained after 70days of inoculum acclimation in comparison to standard cellulose (>600mLN/gVS). Methanogen community analysis based on 16S rDNA of the inoculum revealed Archaea concentration of 3×10(12) gene copies/g (Methanobacteriales 8×10(10); Methanomicrobiales 8×10(10); and Methanosarcinales 4×10(11) gene copies/g). The proposed method for development and maintenance of microorganism enrichment inoculum demonstrates consistent BMP data which is a requirement for dependable prediction of biogas production at field scale operations.