This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by LéJohn, H. B. Articles by Lees, H. Search for Related Content PubMed PubMed Citation Articles by LéJohn, H. B. Articles by Lees, H.

Catabolite Repression in the Facultative Chemoautotroph Thiobacillus novellus

^a Department of Microbiology, University of Manitoba, Winnipeg 19, Manitoba, Canada

ABSTRACT

Several fermentable carbon sources were found to give rise to catabolite repression of all enzymes implicated in thiosulfate oxidation in the facultative chemoautotroph, Thiobacillus novellus. Glucose was found to elicit a strong repression. Glycerol, lactate, lactose, ribose, and pyruvate caused marked repression. In all cases, the repression could be relieved only by returning the cells to a medium devoid of such fermentable substrates. On the other hand, carbon compounds (amino acids and organic acids) that are metabolizable only aerobically caused transient or no repression of the thiosulfate oxidative system. All of the enzymes believed to participate in thiosulfate oxidation, except tetrathionase, were found to be simultaneously induced and repressed. This would suggest that tetrathionate may not be a necessary intermediate in the thiosulfate-oxidation pathway of T. novellus.

¹ Predoctorate fellow.