130. Saxena, I. M. and R. M. Brown, Jr.
1989. Study of cellulose biosynthesis in Acetobacter xylinum:
a genetic approach. In: Cellulose and Wood -Chemistry
and Technology, Ed. C. Schuerch. John Wiley and
Sons, Inc. N. Y., 537-557.
Although a large number of cellulose-synthesizing
strains of Acetobacter xylinum harbor plasmid(s), two wild-type
strains have been found which do not show the presence of any
plasmid DNA. In addition, one plasmid-bearing strain which was
completely cured of its plasmid was still capable of synthesizing
cellulose. It appears that no correlation exists between the
presence of plasmid(s) and the capacity to synthesize cellulose.
By screening for altered colony morphology, mutants deficient
in pellicle production were isolated. All these mutants produced
cellulose II in vivo. Biochemical analysis of these mutants
showed normal activity for in vitro cellulose synthesis.
Lipopolysaccharide isolated from one of the mutants showed absence
of galactose, possibly due to changes in UDPG metabolism. For
an analysis of the mutants by complementation, DNA from two strains
of A. xylinum was cloned in the broad host-range
vectors pRK311 and pMMB33. Recombinant plasmids from A. xylinum
ATCC 53582 gene bank constructed in pRK311 were mobilized into
the mutants at varying frequencies. A recombinant plasmid that
carries a fragment of the plasmid from A. xylinum ATCC
53582 has been identified in the transconjugants in the presence
of which the native plasmid is cured. The considerable variability
that exists in the biosynthesis of cellulose and its organization
in A. Xylinum can now be understood by a detailed genetic
analysis of this bacterium.