Structure of the sulfur inclusion envelopes from four beggiatoas
Abstract
The sulfur inclusions from four strain of Beggiatoa alba were observed by using a ruthenium red-glutaraldehyde technique and a modified Ryter-Kellenberger technique. Three of the four strains contained 4-to 5-nm-thick, single, electron-dense, layered sulfur inclusion envelopes. The fourth strain (B15LD) contained a complex pentalaminar sulfur inclusion envelope, 12-14 nm thick. The sulfur inclusions from all four strains were external to the cytoplasmic membrane but internal to the complex Beggiatoa cell walls. Freeze-etching of the B. alba strain B18LD trichomes revealed the unusual cross-fracture morphology of the sulfur in the inclusions. Fractures around the sulfur inclusions revealed a surface similar to that of the fractured cytoplasmic membrane. © 1981 Springer-Verlag New York Inc.