Microbial ecophysiology of whey biomethanation
The biodegradation of lactose into methane was investigated in a chemostat ecosystem under steady state conditions in order to understand the intermediary metabolism and the responsible bacterial species; and, to model the anaerobic digestion of whey in a continuous contact process. Radioactive carbon tracer studies showed that lactose biomethanation occurred in three distinct but simultaneous metabolic steps with lactate, acetate and hydrogen/carbon dioxide as the major intermediary metabolites. Mixed culture studies on the ecosystem composition demonstrated that multiple species of well described anaerobic bacteria were participating in each of three trophic groups: hydrolytic, acetogenic, and methanogenic. Biomethanation performance studies analyzed the dynamics of bacterial species composition and competition in relation to dilution rate. These results demonstrated that the hydrolytic and acetogenic bacteria were coupled to the methanogenic bacteria by interspecies hydrogen transfer; that species competition and dominance for a given carbon metabolite or for hydrogen was related to specific substrate transformation kinetic properties; and that the data was useful for describing biomethanation with a mechanistic model. Starter cultures were developed by employing freeze drying techniques to preserve either a defined culture comprised of four prevalent digestor species or an adapted chemostat sludge. Both of these starter cultures were shown to effectively degrade lactose using either a defined medium or raw whey as biomethanation starting substrate.
- Research Organization:
- Wisconsin Univ., Madison (USA)
- OSTI ID:
- 6717864
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
LACTOSE
BIODEGRADATION
METHANATION
METHANOGENIC BACTERIA
PHYSIOLOGY
POPULATION DYNAMICS
BIOLOGICAL PATHWAYS
CARBON 14 COMPOUNDS
METHANE
WHEY
ALKANES
BACTERIA
CARBOHYDRATES
CHEMICAL REACTIONS
DECOMPOSITION
DISACCHARIDES
HYDROCARBONS
INDUSTRIAL WASTES
LABELLED COMPOUNDS
MICROORGANISMS
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
SACCHARIDES
WASTES
550701* - Microbiology- Tracer Techniques