| Title | 3-Methylindole production is regulated in Clostridium scatologenes ATCC 25775. | | Author(s) | Doerner KC, Cook KL, Mason BP | | Institution | Department of Biology, Western Kentucky University, Bowling Green, KY, USA. | | Source | Lett Appl Microbiol 2008 Dec 2. | | Abstract | Abstract
Aims: 3-Methylindole (3-MI) is a degradation product of l-tryptophan and is both an animal waste malodorant and threat to ruminant health. Culture conditions influencing 3-MI production in Clostridium scatologenes ATCC 25775 were investigated.
Methods and Results: Extracellular 3-MI levels in cells cultured in brain heart infusion (BHI) medium (pH 7.0) at 33 degrees C and 37 degrees C for 72 h were 907 +/- 38 and 834 +/- 121 mumol l(-1), respectively. Cells cultured in tryptone-yeast (TY) extract medium at 37 degrees C for 48 h produced 104 +/- 86 mumol l(-1) 3-MI; however, addition of 1 mmol l(-1) l-tryptophan failed to increase extracellular levels (113 +/- 50 mumol l(-1) 3-MI). Specific activity of indole acetic acid decarboxylase measured in BHI, TY and TY plus 1 mmol l(-1) tryptophan-grown cells displayed 35-, 33- and 76-fold higher levels than in semi-defined medium-grown cells.
Conclusions: When cultured in rich medium, at 33 degrees C or 37 degrees C and pH 7.0, Cl. scatologenes ATCC 25775 optimally produced 3-MI. Addition of l-tryptophan to medium did not lead to significant increases in extracellular 3-MI levels. Whole cell assays indicate growth in rich medium significantly up-regulated 3-MI production. Significance and Impact of the Study: Information presented here may prove useful in understanding what factors influence 3-MI production in malodorous animal wastes. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19055631 |
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