海洋細菌の無機塩要求性に関する生理学的研究-III

cell-free extractのコハク酸酸化における無機塩要求性

抄録

In order to investigate the mechanism of the type-specific salt requirements for the oxidations in M (marine)-, MH (marine halophilic)-, TH (terrestrial halophilic)-and T (terrestrial)-type bacteria reported in the previous paper, centrifugal supernatants were obtained from mortar-ground frozen cells by centrifuging at 10, 000χg for 30 min. The oxidation of succinic acid was measured with the Warburg respirometer. The supernatant of strain 1055-1 (M-type) required Mg²⁺ and Ca²⁺ but neither Na⁺ nor K⁺ for the succinic acid oxidation. On the other hand, the supernatants of strains 3-1-51 (MH-type) and 2-39 (T-type) did not require any salt. The oxidizing activities of the supernatants of the four types decreased to vanishing point as the centrifugal force was increased from 15, 000χg to 34, 000χg. Recovery of the activities, however, was observed in the 34, 000χg debris prepared from the 10, 000χg supernatants.
It was supposed that the activity for the succinic acid oxidation is present in cell debris, probably cell membrane fragments, and that oxidizing enzymes which are localized on the cell membrane require the type-specific salts.