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Volume 8
Journal of Biotechnology & Biomaterials
ISSN: 2155-952X
Adv.Biotech 2018
November 15-17, 2018
November 15-17, 2018 | Berlin, Germany
4
th
International Conference on
Advances in Biotechnology and Bioscience
Thecellularlocationofendo-actinggalactanasesconferskeystoneorrecipient status toarabinogalactan
degrading organisms of the human gut microbiota
Jose Munoz
Northumbria University, UK
G
lycans, the major source of energy for the human gut microbiota (HGM), are metabolized primarily by the
Bacteroides
genus. Arabinogalactan proteins (AGPs) are a higher heterogenous group of plant glycans in which the β1, 3-galactan
backbone and β1, 6-galactan side chains are conserved features. Diversity is provided by the extensive and highly variable
nature of the sugars that decorate both the backbone and side chain galactans. The mechanisms by which nutritionally relevant
AGPs are degraded at a cellular and biochemical level are poorly understood, as is the impact of this process on the ecology of
the HGM. To address these issues we have explored how the HGM organism
Bacteroides thetaiotaomicron
metabolizes highly
complex AGPs. The work provides a degradative model that reveals a repertoire of exo-acting family GH43 β1, 3-galactanases
that release backbone galactose units that are attached at O6 to the side chains.The oligosaccharide side chains are depolymerized
by the synergistic action of exo-acting enzymes in which catalytic interactions is dependent on whether degradation is initiated
by a lyase or glycoside hydrolase. Growth studies of the 20 HGM
Bacteroides
species on a complex AGP revealed three keystone
organisms that facilitated utilization of fragments of the glycan by the 17 other bacteria, which thus acted as recipients. The
ability to function as a keystone organism was conferred by a surface endo-
β
1, 3-galactanase, which, when engineered into a
recipient enabled the bacterium to also utilize complex AGPs and facilitate the growth of the other
Bacteroides
species. This
study underpins future pre- and pro-biotic strategies to exploit AGPs to manipulate the structure of the HGM.
jlmunoz@um.esJ Biotechnol Biomater 2018, Volume 8
DOI: 10.4172/2155-952X-C6-104