Related Experiment Video
Updated: Aug 6, 2026
12:29
Generation of Null Mutants to Elucidate the Role of Bacterial Glycosyltransferases in Bacterial Motility
Published on: March 11, 2022
Carbohydrate utilization patterns and substrate preferences in Bacteroides thetaiotaomicron
1Medical Research Council, Dunn Clinical Nutrition Centre, Cambridge, UK.
Anaerobe
|February 1, 1995
Summary
Bacteroides thetaiotaomicron efficiently metabolizes hexoses over pentoses. Mannose influences sugar uptake, with xylose utilization being concentration-dependent and inducible transport systems identified.
Area of Science:
- Microbiology
- Bacterial Physiology
- Carbohydrate Metabolism
Background:
- Bacteroides thetaiotaomicron is a key gut commensal.
- Understanding its carbohydrate utilization is crucial for host-microbe interactions.
- Specific mechanisms of sugar uptake and metabolism in B. thetaiotaomicron require elucidation.
Purpose of the Study:
- To investigate the growth rates of B. thetaiotaomicron on various carbon sources.
- To determine the regulatory mechanisms controlling carbohydrate utilization.
- To identify the sugar transport systems and their inducibility.
Main Methods:
- Culturing B. thetaiotaomicron in batch and continuous cultures with different carbon sources.
- Measuring specific growth rates and substrate uptake.
- Utilizing radiolabeled substrates and trichloroacetic acid precipitation.
- Investigating sugar transport inhibition.
Main Results:
- Hexose metabolism (glucose, mannose, galactose) was more efficient than pentose (arabinose, xylose) fermentation.
- Mannose inhibited uptake of other sugars, except xylose, which was concentration-dependent.
- Sugar transport systems for glucose, galactose, xylose, and mannose were inducible.
- Glucose and mannose were primary precursors for macromolecule synthesis.
Conclusions:
- B. thetaiotaomicron possesses distinct and inducible transport systems for various sugars.
- Regulation of sugar uptake is complex and influenced by substrate availability and type.
- Energetic efficiency varies between hexose and pentose metabolism.
More Related Videos
Related Concept Videos
01:26Bacterial Phylum Bacteroidota
The phylum Bacteroidota includes over 700 species classified into four primary orders: Bacteroidales, Cytophagales, Flavobacteriales, and Sphingobacteriales. These gram-negative, non-sporulating rods exhibit saccharolytic capabilities and can be aerobic or fermentative, encompassing obligate aerobes, facultative aerobes, and obligate anaerobes. Many species display gliding motility, though some are nonmotile or use flagella. The genus Bacteroides is well-studied due to its significant role in...
01:25Lipid Catabolism
Triglycerides serve as crucial long-term energy storage molecules in microorganisms, providing a dense source of metabolic energy. Their breakdown is mediated by lipases, which hydrolyze triglycerides into glycerol and free fatty acids. Each of these components follows distinct metabolic pathways, ultimately contributing to ATP synthesis and cellular energy homeostasis.Glycerol MetabolismGlycerol, released from triglyceride hydrolysis, is phosphorylated by glycerol kinase to form...
01:34Introduction to Carbohydrates
Carbohydrates, proteins, and fats are the primary macronutrients in the human diet. However, carbohydrates are the most favored source of energy in the body. They can be found in a wide variety of foods, including whole grains, fruit, and vegetables, in various forms, such as sugars, starch, and dietary fiber. Based on their structure, carbohydrates are classified into three main classes— monosaccharides, disaccharides, and polysaccharides. The body's cells can only utilize simple...
01:27Microbiota of the Large Intestine
The large intestine hosts the most densely populated microbial ecosystem in the human body. This complex community primarily consists of anaerobic bacteria, with Bacillota (formerly Firmicutes) and Bacteroidota (formerly Bacteroidetes) as the predominant groups. The distribution of these microbes varies along different sections of the large intestine, influenced by local environmental factors such as oxygen availability and nutrient composition.The cecum, located at the beginning of the large...
01:28Microbial Nutrition
Organisms exhibit remarkable metabolic diversity, categorized based on how they acquire energy and carbon. These strategies enable survival in various ecological niches and are essential for maintaining energy flow and nutrient cycling within ecosystems.Energy and Carbon SourcesOrganisms are classified as phototrophs or chemotrophs based on energy acquisition. Phototrophs use light as their energy source, while chemotrophs rely on oxidizing chemical compounds. Further differentiation arises...
01:24Bacterial Phylum Tenericutes
The phylum Tenericutes, which includes the single class Mollicutes, comprises bacteria that lack cell walls. The term "Mollicutes" derives from the Latin word mollis, meaning "soft." These organisms are among the smallest known and are commonly referred to as mycoplasmas due to the prominence of the genus Mycoplasma, which includes well-known human pathogens. Despite their inability to stain gram-positively (a result of their lack of cell walls), mycoplasmas are phylogenetically related to the...