Relating methanogen community structure and anaerobic digester function

Abstract

Abstract:Much remains unknown about the relationships between microbial community structure and anaerobic digester function. However, knowledge of links between community structure and function, such as specific methanogenic activity (SMA) and COD removal rate, are valuable to improve anaerobic bioprocesses. In this work, quantitative structure-activity relationships (QSARs) were developed using multiple linear regression (MLR) to predict SMA using methanogen community structure descriptors for 49 cultures. Community descriptors were DGGE demeaned standardized band intensities for amplicons of a methanogen functional gene (mcrA). First, predictive accuracy of MLR QSARs was assessed using cross validation with training (n = 30) and test sets (n = 19) for glucose and propionate SMA data. MLR equations correlating band intensities and SMA demonstrated good predictability for glucose (q 2 = 0.54) and propionate (q 2 = 0.53). Subsequently, data from all 49 cultures were used to develop QSARs to predict SMA values. Higher intensities of two bands were correlated with higher SMA values; high abundance of methanogens associated with these two bands should be encouraged to attain high SMA values. QSARs are helpful tools to identify key microorganisms or to study and improve many bioprocesses. Development of new, more robust QSARs is encouraged for anaerobic digestion or other bioprocesses, including nitrification, nitritation, denitrification, anaerobic ammonium oxidation, and enhanced biological phosphorus removal. Graphical abstract

Perspectives for microbial community composition in anaerobic digestion: from abundance and activity to connectivity

“…A possible approach is the one suggested by Bocher et al . () in which enrichment cultures were used in combination with denaturing gradient gel electrophoresis and mcrA gene analysis for specific methanogenic activity prediction. Given the increasing availability of microbial community composition data in AD via high‐throughput amplicon sequencing and omics methods, this concept can be expanded to develop a suitable prediction strategy.…”

Influent wastewater microbiota and temperature influence anaerobic membrane bioreactor microbial community

“…Produced biogas was then removed and substrate (either acetate or H2/CO2) was added. SMA using acetate was performed for 40 days as described by Bocher et al (2015) using biomass concentration of 1.5 to 1.8 g VS/L and 10 g/L calcium acetate at 10 °C. For SMA using H2/CO2, biomass concentration was 0.2 g VS/L and serum bottle headspace was charged with 100 mL of a 4:1 mixture of H2/CO2 gas that had been previously cooled to 10 °C.…”

“…A high evenness score indicates unique community members are evenly distributed, which is beneficial for functional redundancy (Fernandez et al, 2000). Additionally, ordination techniques including nonmetric multi-dimensional scaling (NMDS) and principal component analysis (PCA) have been useful to compare microbial community differences in separate systems (Bialek et al, 2011 andBocher et al, 2015).…”

mcrA Gene abundance correlates with hydrogenotrophic methane production rates in full-scale anaerobic waste treatment systems

“…Methanogens possess an operon that encodes the methyl coenzyme M reductase (MCR). The presence and transcription of the gene that encodes the alpha subunit of MCR (mcrA) has been used to detect methanogen presence and activity in the environment (Springer et al 1995;Luton et al 2002;Juottonen et al 2008;Steinberg and Regan 2009;Kampmann et al 2012;Zeleke et al 2013;Bocher et al 2015). Previously, we showed that mcrA gene copy numbers, but not transcript numbers, positively correlated with SMA values in laboratory methanogenic enrichments (Morris et al 2014).…”

“…; Bocher et al . ). Previously, we showed that mcrA gene copy numbers, but not transcript numbers, positively correlated with SMA values in laboratory methanogenic enrichments (Morris et al .…”