Regulation of metabolic pathways in sulfobacilli under different aeration regimes

• Published in: Microbiology (New York) Vol. 79; no. 2; pp. 147 - 152
• Main Authors: Krasil'nikova, E. N, Zakharchuk, L. M, Egorova, M. A, Bogdanova, T. I, Zhuravleva, A. E, Tsaplina, I. A
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : SP MAIK Nauka/Interperiodica 01-04-2010; SP MAIK Nauka/Interperiodica
• Subjects: Biomedical and Life Sciences; Experimental Articles; Life Sciences; Medical Microbiology; Microbiology; acidothermophilic sulfobacilli; carboxylases; aeration conditions; carbon metabolism enzymes; TCA cycle
• ISSN: 0026-2617; 1608-3237
• DOI: 10.1134/S0026261710020037

A comparative study of the activities of the enzymes of carbon metabolism from the cells of moderately thermophilic chemolithotrophic bacteria Sulfobacillus sibiricus (strains N1 and SSO) and Sulfobacillus thermosulfidooxidans subsp. asporogenes (strain 41) was carried out grown in a high layer of medium without forced aeration and cells grown with intense aeration. Limited air access to the growing S. sibiricus N1 cells resulted in switching from the pentose phosphate pathway of glucose metabolism to the Entner-Doudoroff pathway while the Embden-Meyerhof-Parnas pathway persisted. Irrespective of the level of the aeration, in the cells of S. sibiricus SSO and S. thermosulfidooxidans subsp. asporogenes 41, degradation of the glucose occurred via the Entner-Doudoroff and pentose phosphate metabolic pathways, respectively, as well as via the Embden-Meyerhof-Parnas pathway. Prolonged growth of S. sibiricus, strains N1 and SSO, in a high layer of the medium without forced aeration led to the repression of synthesis of most of the tricarboxylic acid cycle (TCA cycle) enzymes, in particular dehydrogenases, as well as of some carboxylases including RuBisCO. The traits of carbon metabolism in various strains of Sulfobacillus under conditions of oxygen deficiency are discussed.