# CATABOLISM OF POLYSACCHARIDES BY COLONIC BACTEROIDES

> **NIH NIH R01** · UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN · 1993 · $189,485

## Abstract

Bacteroides are gram negative obligately anaerobic bacteria that account
for 25% of the complex microbial population that resides in the normal
human colon.  These bacteria are notable for their ability to utilize a
variety of polysaccharides, and they may be responsible for the extensive
digestion of dietary and host polysaccharides that occurs in the colon.
Bacteroides are also the main cause of opportunistic anaerobic infections
in humans, and their ability to degrade tissue polysaccharides may
contribute to their virulence.  Bacteroides polysaccharide-degrading
enzymes are generally not extracellular, and there appear to be outer
membrane proteins that bind polysaccharides and facilitate their passage
through the outer membrane.  We will use biochemical and genetic techniques
to investigate the steps involved in catabolism of polysaccharides by
Bacteroides.  We will clone polysaccharide utilization genes by
complementing mutations that affect early steps in catabolism and use these
clones to determine the number and organization of genes needed for
catabolism.  We will use gene disruption techniques to assess the
contribution of various polysaccharides and membrane proteins to the
degradative process.  We will also use cloned genes and regulatory mutants
to determine how polysaccharide utilization genes are regulated.
Information obtained in these pure culture studies will be used to develop
methods for determining what Bacteroides are actually doing in the colon.
Specifically, we will use antiserum that detects polysaccharide-regulated
proteins to determine whether these proteins are expressed at induced
levels in human feces.  We will also use germfree mice as a model system
for testing the effect of mutations in intestinal tract.  The results of
these experiments should provide new information about the activities of
the human colonic microflora and how these activities are affected by the
host's diet.

## Key facts

- **NIH application ID:** 3127481
- **Project number:** 5R01AI017876-13
- **Recipient organization:** UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
- **SAM.gov UEI:** Y8CWNJRCNN91
- **Principal Investigator:** Abigail A Salyers
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $189,485
- **Award type:** 5
- **Project period:** 1981-04-01 → 1994-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3127481

## Citation

> US National Institutes of Health, RePORTER application 3127481, CATABOLISM OF POLYSACCHARIDES BY COLONIC BACTEROIDES (5R01AI017876-13). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3127481. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*