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The goal of this study was to obtain causative information about beta-diversity (differentiation between microbiomes) by comparing sequencing information between studies rather than just knowledge about alpha-diversity (microbiome richness). Here, published sequencing data were merged representing 78 anaerobic digester samples originating from 28 different studies for an overall comparison of beta-diversity (measured using unweighted UniFrac). It was found that digester microbiomes based on bacterial sequences clustered by substrate type, independent of the study of origin, and that this clustering could be attributed to distinct bacterial lineages., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Anaerobic digestion of brewery wastewater solids in the form of primary sludge was investigated for its potential as a source of energy (methane). We operated a low-rate (hydraulic retention time (HRT)=solids retention time (SRT)) continuously stirred anaerobic digester (CSAD) and a high-rate (SRT>HRT) anaerobic sequencing batch reactor (ASBR) in parallel for 250 days. We found that high-rate anaerobic digestion was beneficial for solids-rich waste flows even during a long-term operating period that included a shock load of nonbiodegradable total solids. The ASBR biomass achieved a higher specific methanogenic activity compared to the CSAD biomass (0.257+/-0.043 vs. 0.088+/-0.008 g CH(4)-COD g(-1)VSS d(-1)), which aided in stability during the shock load with total solids. The methane yield for the ASBR was 40-34% higher than for the CSAD (0.306 vs. 0.219 l CH(4)g VS(-1) fed for days 1-183 and 0.174 vs. 0.130 l CH(4)g VS(-1) fed for days 184-250, respectively). Finally, we operated an ASBR for an additional 295 days to evaluate the effect of temperature variation on system stability. A stable performance was achieved between the operating temperatures of 22-41 degrees C., ((c) 2010 Elsevier Ltd. All rights reserved.)