Initial catabolism of sorbitol in Actinomyces naeslundii and Actinomyces viscosus.

Abstract

The initial steps of sorbitol catabolism were studied in 4 strains of Actinomyces naeslundii and Actinomyces viscosus that had been isolated from human dental plaque. Cell-free extracts were prepared from cells grown in the presence of either sorbitol, xylitol or glucose. The extracts from all strains grown on sorbitol had nicotinamide adenine dinucleotide-linked dehydrogenase activities for sorbitol and xylitol and reduced nicotinamide adenine dinucleotide-linked reductase activities for fructose and xylulose. Two of the strains also exhibited these activities when grown in the presence of xylitol, and all glucose-grown cells lacked them. The results indicate that sorbitol metabolism in oral actinomyces involve oxidation of sorbitol to fructose by an inducible enzyme, nicotinamide adenine dinucleotide-linked sorbitol dehydrogenase. This step is followed by the phosphorylation of fructose with guanosine triphosphate as a main phosphoryl donor. Thus, the initial catabolic pathway of sorbitol in A. naeslundii and A. viscosus is different from those described for other oral bacteria.

• Authors: S Kalfas, N Takahashi, T Yamada
• Journal: Oral microbiology and immunology (Oral Microbiol Immunol) Vol. 9 Issue 6 Pg. 372-5 (Dec 1994) ISSN: 0902-0055 [Print] Denmark
• PMID: 7870473 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Fructosephosphates
• NAD
• Sorbitol
• fructose-6-phosphate
• Oxidoreductases
• L-Iditol 2-Dehydrogenase
• NADH, NADPH Oxidoreductases
• Hexokinase

Topics

• Actinomyces (metabolism)
• Actinomyces viscosus (metabolism)
• Enzyme Induction
• Fructosephosphates (metabolism)
• Hexokinase (metabolism)
• L-Iditol 2-Dehydrogenase (metabolism)
• NAD (metabolism)
• NADH, NADPH Oxidoreductases (metabolism)
• Oxidoreductases (metabolism)
• Sorbitol (metabolism)