Chemosynthetic fixation of carbon dioxide and characteristics of hydrogenase in resting cell suspensions of Hydrogenomonas ruhlandii nov. spec.

The use of molecular hydrogen by "Knallgas" or hydrogen-oxidizing bacteria was first described by Kaserer (1905, 1906). Subsequently, other investigators such as Nabokitch and Lebedeff (1907), Lebedeff (1908), Niklewski (1910, 1914), and especially Ruhiand (1924) have characterized this group of facultative autotrophs primarily with regard to their distribution, growth requirements, and quantitative consumption of carbon dioxide, oxygen, and hydrogen by growing cultures. Some of the results of the earlier work have been recently reviewed by Gest (1954) and Schlegel (1954). Surprisingly little is known of the mechanism by which hydrogen is utilized by these organisms, which when grown autotrophically depend entirely on hydrogen oxidation for energy. To study the mechanism of hydrogen oxidation a Knallgas bacterium, later named Hydrogenomonar ruhlandii, was isolated from soil. This organism was found to be amenable to an enzymatic study of the reactions involved in hydrogen activation and transfer (Packer and Vishniac, 1954, 1955). It is hoped that the information obtained on the hydrogen metabolism of this species may be of general significance for the physiological type it represents. This paper reports on the isolation, cultivation, and some physiological characteristics of the new species herein described.