Pure culture, co-culture and whole ecosystem investigations of single anaerobes, partnerships and microbial communities in anaerobic digestion
MetadataShow full item record
This item's downloads: 35 (view details)
Anaerobic digestion (AD) is a multi-stage process whereby biodegradable material is broken down by complex microbial consortia into renewable CH4 in the absence of oxygen during waste and wastewater treatment. Anaerobic granules are spherical microbial biofilms which form in digesters such as upflow anaerobic sludge blanket (UASB) and expanded granular sludge blanket (EGSB) systems. There is a fundamental knowledge gap in the microbial dynamics and metabolic interactions among microorganisms within AD bioreactors. This thesis addressed some growth and chemical aspects resulting from microbial interplay between three model pure cultures found in AD digesters under various temperature and substrate conditions. The methanogen Methanosarcina barkeri is a metabolically diverse organism, independent of temperature, which was demonstrated to grow synergistically with the homoacetogen Acetobacterium woodii. The competitive interaction between Methanosarcina barkeri and the hydrogenotrophic methanogen Methanococcus maripaludis is novel within the literature. Methanococcus maripaludis out-competed Methanosarcina barkeri for H2-CO2 but both pure cultures were able to grow together. Physical, physiological and phylogenetic properties of anaerobic granules were significantly different at three designated size distributions. Physiological and phylogenetic characteristics of anaerobic granules from three sources were significantly different. Individual anaerobic granules had significantly similar physical characteristics and active community structures based on 16S rRNA Illumina sequencing. Single anaerobic granules were described as “whole ecosystems” because they had a statistically similar active microbial profile. Micro Sequencing Batch Reactors were employed to analyse how individual anaerobic granules/“whole ecosystems” respond to various environmental stresses. Results from VFA profiling and sequencing indicated that single granules demonstrated replicated shifts in metabolic and community structure patterns. In conclusion, a combination of both pure cultures and high-throughput sequencing studies of mixed microbial communities show potential as one tool to underpin the understanding of complex systems such as anaerobic digestion.
This item is available under the Attribution-NonCommercial-NoDerivs 3.0 Ireland. No item may be reproduced for commercial purposes. Please refer to the publisher's URL where this is made available, or to notes contained in the item itself. Other terms may apply.
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Low-temperature anaerobic digestion is associated with differential methanogenic protein expression Gunnigle, Eoin; Siggins, Alma; Botting, Catherine H.; Fuszard, Matthew; O'Flaherty, Vincent; Abram, Florence (Oxford University Press, 2015-04-09)Anaerobic digestion (AD) is an attractive wastewater treatment technology, leading to the generation of recoverable biofuel (methane). Most industrial AD applications, carry excessive heating costs, however, as AD reactors ...
Metal concentrations in lime stabilised, thermally dried and anaerobically digested sewage sludges. Healy, Mark G.; Brennan, Raymond B.; Morrison, Liam (Elsevier ScienceDirect, 2015-11-25)Cognisant of the negative debate and public sentiment about the land application of treated sewage sludges ( biosolids ), it is important to characterise such wastes beyond current regulated parameters. Concerns may be ...
Nzeteu, Corine (2016-04-28)Landfill, incineration, compositing and anaerobic digestion (AD) are the principal food-waste (FW) treatment methods used in the European Union. Because of the EU landfill directive and waste-management policies on organic ...