https://dx.doi.org/10.1128/jb.169.11.5054-5059.1987">
 

Abstract

Vesicles, specialized cell structures thought to be the site of nitrogen fixation in the actinorhizal bacteria, were isolated from Frankia sp. strain EAN1pec by using French pressure disruption of mycelia followed by differential and isopycnic gradient centrifugation. The isolated vesicles reduced acetylene when incubated anaerobically with Mg2+ ions, ATP, and dithionite. No nitrogenase activity was detected in the disrupted mycelial fractions. Vesicles permeabilized by freeze-thaw or detergents showed increased rates of acetylene reduction due to increased permeability of dithionite. The effect on nitrogenase activity of different ATP concentrations was the same in normal and permeabilized vesicles. The endogenous respiratory rate of vesicles was significantly lower than that of mycelia, and the respiration rate of vesicles did not increase following the addition of succinate. The low respiratory activity of vesicles and their apparent dependence on externally supplied ATP for acetylene reduction suggest that the energy and reducing power for nitrogen fixation may be supplied from the mycelia to which they are attached.

Publication Date

11-1-1987

Journal Title

Journal of Bacteriology

Publisher

American Society for Microbiology

Digital Object Identifier (DOI)

https://dx.doi.org/10.1128/jb.169.11.5054-5059.1987

Document Type

Article

Comments

This is an article published by American Society for Microbiology in Journal of Bacteriology in 1987, available online: https://dx.doi.org/10.1128/jb.169.11.5054-5059.1987

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