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Appl Environ Microbiol. Aug 1995; 61(8): 3180–3184.
PMCID: PMC167595

3-Methylindole (skatole) and indole production by mixed populations of pig fecal bacteria.


Pig fecal slurries converted added L-tryptophan either to indole without detectable intermediates or to 3-methylindole (skatole) via indole-3-acetate. The initial rate of production of 3-methylindole was greatest at pH 6.5 and less at pH 5.0 and 8.0; the initial rates of indole production were similar at pH 6.5 and 8.0. More than 80% of the tryptophan added was converted to 3-methylindole at pH 5.0; at pH 8.0 85% was converted to indole. Both pathways had similar Km values for tryptophan and similar maximum rates. Indole-3-carbinol and indole-3-acetonitrile completely inhibited the production of 3-methylindole from indole-3-acetate but had no effect on the reactions involving L-tryptophan.

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Selected References

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  • Carlson JR, Yokoyama MT, Dickinson EO. Induction of pulmonary edema and emphysema in cattle and goats with 3-methylindole. Science. 1972 Apr 21;176(4032):298–299. [PubMed]
  • Chung KT, Anderson GM, Fulk GE. Formation of indoleacetic acid by intestinal anaerobes. J Bacteriol. 1975 Oct;124(1):573–575. [PMC free article] [PubMed]
  • Fellers CR, Clough RW. INDOL AND SKATOL DETERMINATION IN BACTERIAL CULTURES. J Bacteriol. 1925 Mar;10(2):105–133. [PMC free article] [PubMed]
  • Hammond AC, Carlson JR. Inhibition of ruminal degradation of L-tryptophan to 3-methylindole, in vitro. J Anim Sci. 1980 Jul;51(1):207–214. [PubMed]
  • Honeyfield DC, Carlson JR. Assay for the enzymatic conversion of indoleacetic acid to 3-methylindole in a ruminal Lactobacillus species. Appl Environ Microbiol. 1990 Mar;56(3):724–729. [PMC free article] [PubMed]
  • Jensen BB, Jørgensen H. Effect of dietary fiber on microbial activity and microbial gas production in various regions of the gastrointestinal tract of pigs. Appl Environ Microbiol. 1994 Jun;60(6):1897–1904. [PMC free article] [PubMed]
  • Jensen MT, Jensen BB. Gas chromatographic determination of indole and 3-methylindole (skatole) in bacterial culture media, intestinal contents and faeces. J Chromatogr B Biomed Appl. 1994 May 13;655(2):275–280. [PubMed]
  • ROSENBERGER RF. Obligate anaerobes which form skatole. J Bacteriol. 1959 Apr;77(4):517–517. [PMC free article] [PubMed]
  • Spray RS. Three New Species of the Genus Clostridium. J Bacteriol. 1948 Jun;55(6):839–842. [PMC free article] [PubMed]
  • Yokoyama MT, Carlson JR. Dissimilation of tryptophan and related indolic compounds by ruminal microorganisms in vitro. Appl Microbiol. 1974 Mar;27(3):540–548. [PMC free article] [PubMed]
  • Yokoyama MT, Carlson JR. Microbial metabolites of tryptophan in the intestinal tract with special reference to skatole. Am J Clin Nutr. 1979 Jan;32(1):173–178. [PubMed]
  • Yokoyama MT, Carlson JR. Production of Skatole and para-Cresol by a Rumen Lactobacillus sp. Appl Environ Microbiol. 1981 Jan;41(1):71–76. [PMC free article] [PubMed]
  • Yokoyama MT, Carlson JR, Holdeman LV. Isolation and characteristics of a skatole-producing Lactobacillus sp. from the bovine rumen. Appl Environ Microbiol. 1977 Dec;34(6):837–842. [PMC free article] [PubMed]

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