TITLE:
Phylogenetic Analysis of Anaerobic Co-Digestion of Animal Manure and Corn Stover Reveals Linkages between Bacterial Communities and Digestion Performance
AUTHORS:
Fan Yang, Rui Chen, Zhengbo Yue, Wei Liao, Terence L. Marsh
KEYWORDS:
Anaerobic Co-Digestion, Bacteroidetes, Cellulose Degrading Bacterial Community
JOURNAL NAME:
Advances in Microbiology,
Vol.6 No.12,
October
17,
2016
ABSTRACT: Over 3 million tons of manures are produced annually
in the United States and pose environmental and health risks if not remediated.
Anaerobic digestion is an effective method in treating organic wastes to reduce
environmental impacts and produce methane as an alternative energy. Previous
studies suggested that optimization of feed composition, hydraulic retention
time, and other operational conditions can greatly improve total solids removal
and increase methane productivity. These environmental factors improve functionality
by altering the microbial community structure but explicit details of how the
bacterial community shifts are poorly understood. Our investigations were
conducted to investigate the relationship between environmental factors,
microbial community structure and bioreactor efficiency by using metagenomic
analysis of the microbial communities. Our results indicated that the
bioreactor with the greatest methane production, digestion efficiency and
reduced levels of E. coli/Shigella had a distinctive community
structure at the genus level with unique and abundant uncultivated strains of
Bacteroidetes. Moreover the same bioreactor was enriched in Aminomonas
paucivorans and Clostridia populations that can utilize secondary metabolites
produced during cellulose/hemicellulose degradation to generate hydrogen and
acetate. Hence specific digestion conditions that enrich for these populations
may provide a route to the optimization of co-digestion systems and control the
variability in reactor performance.