Denne oppgaven ble basert på en metagenomisk studie av en switchgrass prøve fra kumage, hvor videre undersøkelser fant et antatt cellulolytisk genkluster, fra en Bacteroidetes fylotypes genom (AGa), med fire antatt cellulolytiske glykosid-hydrolase familie 5 (GH5) enzymer.
Klusteret inneholdt både multi-domene enzymer og enzymer med et C-terminalt sekresjonssignal for Type IX sekresjonssystemet (T9SS).
Lignocellulosic biomass is generally regarded as a sustainable and environmentally friendly energy source.
However, the production of fuels from biomass is not sufficiently effective to compete fully with fossil fuels on economic terms, mostly due to the low efficiency of the enzymes needed to degrade the biomass.
Lignocellulose er den mest forekommende biomassen på jorden og har et stort potensiale som kilde til bærekraftig produksjon av verdifulle produkter som kjemikalier og biodrivstoff.
Dagens uttømming av fossile brennstoffreserver og forurensning fra bruken av disse viser behovet for en mer bærekraftig kilde til energi.The cluster contained both multi-domain enzymes and enzymes with a C-terminal secretion tag for the Type IX secretion system (T9SS).The T9SS has been linked to cellulose degradation in Bacteroidetes.Thus, the need for better enzymes for the conversion of biomass to sugars and eventually biofuels is evident, and a better understanding of how biomass conversion occurs in nature may lead to improvements in the technology.This thesis was based on a metagenomic study of a cow rumen microbiome sample enriched on switchgrass, where further investigation revealed a putative cellulolytic gene cluster, from a Bacteroidetes-affilated phylotype genome (AGa), with four putative cellulolytic glycoside hydrolase 5 (GH5) family enzymes.The cluster enzyme characterization gives insight into the use of the Type IX secreted multi-domain cellulases.Further work on the gene cluster can provide more insight into the degradation mechanism, and expression of the cluster in a bacterium harbouring the Type IX secretion system could be pursued to improve the expression of the multi-domain cellulases that were difficult to express.Lignocellulose is the most abundant biomass on earth and has a great potential as a source for sustainable production of valuable chemicals and biofuels.Today’s depletion of fossil fuel reserves and pollution from their usage creates a need for a more sustainable source of energy.Finally, metaproteomics was performed on a cow rumen sample in an attempt to reveal the presence of the enzymes in vivo.Characterization revealed cellulase activity on crystalline cellulose, filter paper, for almost all GH5 enzymes present in the cluster.