Poly-beta-hydroxybutyrate in the chemolithotrophic bacterium Ferrobacillus ferrooxidans

W S Wang, D G Lundgren
1969 Journal of Bacteriology  
Poly-f-hydroxybutyric acid (PHB) has been demonstrated in a wide range of bacteria, including both chemolithotrophic and photolithotrophic organisms. In the chemolithotrophic group, Schlegel, Gottschalk, and von Bartha (8) reported the formation and utilization of PHB in Hydrogenomonas, Lundgren et al. (4) extracted PHB from Ferrobacillusferrooxidans, and Tobback and Laudelout (10) chemically identified PHB in Nitrobacter. In thin sections of the photosynthetic bacterium Rhodospirillum rubrum,
more » ... ospirillum rubrum, Vatter and Wolfe (11) reported fat vacuoles in the cell's cytoplasm which Cohen-Bazire and Kunisawa (2) later identified as PHB granules. The existence of a limiting membrane surrounding the PHB granule was reported by Boatman (1); it was a single membrane about 4 nm wide. Pfister and Lundgren (6) also reported a membrane around PHB granules in Bacillus cereus. The membrane was seen on isolated PHB granules examined as carbon replicas (5) . In this report, morphological evidence is given for the presence of PHB granules in F. ferrooxidans grown heterotrophically with glucose as the primary energy source. F. ferrooxidans was grown in the 9K salts medium of Silverman and Lundgren (9) with 0.5% glucose as the energy source instead of iron. The cultural conditions were those reported in the earlier report of Remsen and Lundgren (Bacteriol. Proc., p. 33, 1963). The cells were harvested, washed with a solution of ethylenediaminetetraacetate (2 X 10-' M), fixed with 0.5% glutaraldehyde in collidine buffer (0.5 M, pH 7.6) for 30 min, and postfixed with 1% osmium tetroxide in distilled water overnight. Sections were poststained with 1 % uranyl acetate for 60 min at 60 C, followed by lead citrate (7) for 5 min at room temperature. Electron micrographs were taken with an RCA EMU-2D electron microscope operating at 50 kv. An increase in cell number was observed when F. ferrooxidans was grown under heterotrophic
doi:10.1128/jb.97.2.947-950.1969 fatcat:yzqlx7ripzhrvn3ljl6bweixiu