It has been reported that the instability of the
Acetobacter strain results in spontaneous mutants or
variants that do not produce cellulose under agitated conditions.
Hestrin and Schramm (9) studied the influence
of agitation on the production of cellulose from a
swirling culture of A. xylinum. They found that the
decline of cellulose production is associated with the
overgrowth of non-cellulose producing mutants resulting
from the shear force generated by swirling. Our shaking
culture experiments showed that non-cellulose producing
(Cell) mutants did not appear when the shaking speed
was below 200rpm and the volume fraction was lower
than 0.2.