Investigation and Alteration of Organic Acid Synthesis Pathways in the Mammalian Gut Symbiont Bacteroides thetaiotaomicron
Journal article, 2022

Members of the gut-dwelling Bacteroides genus have remarkable abilities in degrading a diverse set of fiber polysaccharide structures, most of which are found in the mammalian diet. As part of their metabolism, they convert these fibers to organic acids that can in turn provide energy to their host. While many studies have identified and characterized the genes and corresponding proteins involved in polysaccharide degradation, relatively little is known about Bacteroides genes involved in downstream metabolic pathways. Bacteroides thetaiotaomicron is one of the most studied species from the genus and is representative of this group in producing multiple organic acids as part of its metabolism. We focused here on several organic acid synthesis pathways in B. thetaiotaomicron, including those involved in formate, lactate, propionate, and acetate production. We identified potential genes involved in each pathway and characterized these through gene deletions coupled to growth assays and organic acid quantification. In addition, we developed and employed a Golden Gate-compatible plasmid system to simplify alteration of native gene expression levels. Our work both validates and contradicts previous bioinformatic gene annotations, and we develop a model on which to base future efforts. A clearer understanding of Bacteroides metabolic pathways can inform and facilitate efforts to employ these bacteria for improved human health or other utilization strategies.

Organic acid

Genetics

Bacteroides

Fermentation

Metabolism

Author

Nathan Porter

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Johan Larsbrink

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Microbiology spectrum

2165-0497 (eISSN)

Vol. 10 1 e02312-21

Development of a consolidated bioprocess for conversion of plant biomass to versatile chemical building blocks

ÅForsk (17-345), 2017-07-01 -- 2018-05-31.

Swedish Research Council (VR) (2016-03931), 2017-01-01 -- 2020-12-31.

Novo Nordisk Foundation (NNF17OC0027648), 2018-01-01 -- 2020-12-31.

Subject Categories

Microbiology

Bioinformatics and Systems Biology

Genetics

DOI

10.1128/spectrum.02312-21

PubMed

35196806

More information

Latest update

4/21/2022