Figure 2.4
    
    
CH 2 OH
4βDGlc(1  4)βGlc
3
1
αDMan
1
2
H
H
H
H
H
OH
HO
Glucose
Residue
Repeating fructofuranosyl unit
β(2  6) links
HO
O
O
HOH 2 C
OH
HO
H
CH 2
H
H
O
HOH 2 C
OH
HO
H
CH 2
H
H
n
O
O
1
2
5
6
4
3
βDGlcA
(b)
4
1
αDGlc
6
1
βDGlc
6
1
αLRha
(a)
 
26
Bacterial Cellulose
Figure 2.4
(a).Acetan:.Glc.=.glucose;.Man.=.mannose;.GlcA.=.glucuronic.acid;.Rh.=.rhamnose..Adapted.
from.Kirby.et.al..(1995)..(b).Levan..Adapted.from.Arvidson.et.al..(2006).
grown.in.the.presence.of.sucrose.and.the.least.when.grown.in.the.presence.of.
glucose,.depending.on.the.formation.of.ketogluconate.acids.
The. production. of. these. polysaccharides. can. differ,. especially. between.
mutants.and.wild-type.strains.of.G. xylinus..The.accumulated.poly. saccharides.
interfere.with.the.cellulose.crystallization.process.by.preventing.hydrogen.
bonding.between.the.produced.microfibrils.(Watanabe.et.al..1998).
Ishida.et.al..(2002).investigated.a.mutant.of.G. xylinus,.EP1,.that.was. not.
able.to.produce.acetan..The.hypothesis.is.that.this.mutant.therefore.should.
produce.more.BNC,.since.more.of.the.carbon.source.can.be.used.for.BNC.
production..The.outcome.was.the.opposite,.however;.the.mutant.produced.
less.BNC.than.the.wild-type.G. xylinus,.which.was.used.as.a.reference..When.
acetan.was.added.to.the.cultivation.medium.for.the.EP1.mutant.strain,.BNC.
production.was.stimulated.and.the.final.yield.was.almost.equal.to.the.yield.
of. the. wild-type. strain.. The. same. phenomenon. was. seen. when. agar. was.
added. to. the. cultivation. medium.. The. conclusion. that. can. be. drawn. from.
these.results.is.that.the.production.of.cellulose.is.dependent.on.how.viscous.
the.cultivation.medium.is.during.cultivation.(Ishida.et.al..2002).
Effect of Growth Medium Components on
Bacterial Cellulose Production in G. xylinus
The. growth. media. components. have. a. great. impact. on. BNC. production.
in. terms. of. cellulose. production. rate,. yield,. and. network. structure.. The.