66. Brown, Jr. R. M., Willison, J. H. M.,
and C. L. Richardson. 1976. Cellulose biosynthesis in Acetobacter
xylinum: 1. Visualization of the site of synthesis and direct
measurement of the in vivo process. Proc. Nat. Acad.
Sci. U.S.A. 73(12):4565-4569.
66. Abstract
In vivo
synthesis of cellulose by Acetobacter xylinum was monitored
by darkfield light microscopy. Cellulose is synthesized in the
form of a ribbon projecting from the pole of the bacterial rod.
The ribbon elongates at a rate of 2 m min-1. The
ribbon consists of approximately 46 microfibrils which average
1.6 x 5.8 nm in cross section. The observed microfibrillar elongation
rate corresponds to 470 amol of glucose/cell per hr assimilated
into cellulose. Electron microscopy of the process using negative
staining, sectioning, and freeze-etching indicated the presence
of approximately 50 individual synthetic sites organized in a
row along the longitudinal axis of the bacterial rod and in close
association with the outer envelope. The process of cellulose
synthesis in Acetobacter is compared with that in eukaryotic
plant cells.