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 Daron, H. H. Search for Related Content PubMed PubMed Citation Articles by Daron, H. H.

Occurrence of Isocitrate Lyase in a Thermophilic Bacillus Species

Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas

ABSTRACT

A thermophilic, sporeforming bacterium has been isolated from soil on a medium containing acetate as a carbon source. This organism is similar to Bacillus stearothermophilus in most respects but differs in its inability to hydrolyze starch. Isocitrate lyase is present in cell-free extracts of organisms grown in a medium with acetate as a carbon source. The specific activity was 400 times lower in extracts of organisms utilizing glucose as a carbon source. With crude extracts, enzyme activity was strongly stimulated by Mg⁺⁺, but cysteine and ethylenediaminetetraacetate had little effect. It appeared to be more heat-stable than the pure isocitrate lyase from Pseudomonas indigofera.