83. Haigler, C., Brown, Jr. R. M., and M.
Benziman. 1980. Calcofluor White ST alters the in vivo
assembly of cellulose microfibrils. Science 210:903-906
(cover).
83. Abstract
The fluorescent brightener, Calcofluor
White ST, prevents the in vivo assembly of crystalline
cellulose microfibrils and ribbons by Acetobacter xylinum.
In the presence of more than 0.01 percent Calcofluor, Acetobacter
continues to synthe-size high-molecular-weight -1,4 glucans.
X-ray crystallography shows that the altered product exhibits
no detectable crystallinity in the wet state, but upon drying
it changes into crystalline cellulose I. Calcofluor alters cellulose
crystallization by hydrogen bonding with glucan chains. Synthesis
of this altered product is reversible and can be monitored with
fluorescence and electron microscopy. Use of Calcofluor has made
it possible to separate the processes of polymerization and crystallization
leading to the biogenesis of cellulose microfibrils and has suggested
that crystallization occurs by a cell-directed, self-assembly
process in Acetobacter xylinum.