Figure 11.2b
Incorporated GlcNAc (mole%)
0.4
0.3
0.2
0.1
0.0
M1604 1604A
AJ2000 1604B
M0020 1604B
M1010 1010A
M0020 1010B
M0416 0416A
M0020 0416B
1
2
3
4
5
6
7
8
Cultivation Time (day)
224
Bacterial Cellulose
Figure 2b
Amount.of.incorporated.GlcNAc.in.bacterial.cellulose.as.a.function.of.cultivation.time..Source:.
From.Nge.et.al.,.Biopolymers.(ISBN:978-953-307-109-1,.InTech.,.2010),.345–368,.with.permission.
measured.by.liquid.scintillation..The.total.amount.of.incorporated.GlcNAc.
was.then.calculated.from.the.levels.of.radioactivity.measured.
tion.time.from.different.starter.cultures.is.shown.in.Figure 11.2b..A.detectable. level. of. GlcNAc. incorporation. was. observed. at. day. 2.. The. measured.
radioactivity. increased. until. day. 3. in. M0416-0416A,. M0020-M0416B,. and.
M0020-M1010B;.and.day.5.in.M1010-M1010A,.M1604-M1604A,.M0020-M1604B,.
and. AJ2000-M1604B.. They. were. fairly. stable. after. 5. days,. which. indicated.
that. the. incorporation. of. GlcNAc. occurred. essentially. in. early. incubation. times,. within. 5. days.. This. finding. was. in. agreement. with. the. higher.
. cellulose.mass.observed.at.an.early.incubation.time.in.the.media.containing.
mixed.sugars.compared.to.the.medium.containing.glucose.only,.as.shown.in.
Figure 11.2a..The.level.of.GlcNAc.incorporated.after.7.days.was.in.the.range.
of. 0.03–0.36. mole%,. depending. on. the. amount. of. nonradioactive. GlcNAc.
present.in.the.culture.medium.and.the.type.of.starter.culture.used.
tions.(decreasing.glucose.concentrations).in.the.culture.medium..The.presence.of.high.GlcNAc.concentrations.with.a.concomitant.decrease.in.glucose.
content. may. limit. the. activity. of. cellulose. biosynthesis.. Therefore. the. time.
course.of.cellulose.production.in.the.medium.containing.a.high.concentration.
of.nonradioactive.GlcNAc.(M0020-0416B).showed.a.lower.profile.than.that.of.
lation..In.addition,.the.effect.of.the.type.of.starter.culture.on.GlcNAc.incorporation.was.observed.in.the.glucose.GlcNAc.1010.and.1604.media..The.starter.
cultures.containing.the.same.sugar.content.(e.g.,.inoculation.of.M1604.starter.
culture. into. 1604. medium). led. to. higher. amounts. of. GlcNAc. incorporation.
than.inoculums.from.the.medium.containing.GlcNAc.only.(i.e., inoculation.
Incorporated GlcNAc (mole%)
0.4
0.3
0.2
0.1
0.0
M1604 1604A
AJ2000 1604B
M0020 1604B
M1010 1010A
M0020 1010B
M0416 0416A
M0020 0416B
1
2
3
4
5
6
7
8
Cultivation Time (day)
224
Bacterial Cellulose
Figure 2b
Amount.of.incorporated.GlcNAc.in.bacterial.cellulose.as.a.function.of.cultivation.time..Source:.
From.Nge.et.al.,.Biopolymers.(ISBN:978-953-307-109-1,.InTech.,.2010),.345–368,.with.permission.
measured.by.liquid.scintillation..The.total.amount.of.incorporated.GlcNAc.
was.then.calculated.from.the.levels.of.radioactivity.measured.
tion.time.from.different.starter.cultures.is.shown.in.Figure 11.2b..A.detectable. level. of. GlcNAc. incorporation. was. observed. at. day. 2.. The. measured.
radioactivity. increased. until. day. 3. in. M0416-0416A,. M0020-M0416B,. and.
M0020-M1010B;.and.day.5.in.M1010-M1010A,.M1604-M1604A,.M0020-M1604B,.
and. AJ2000-M1604B.. They. were. fairly. stable. after. 5. days,. which. indicated.
that. the. incorporation. of. GlcNAc. occurred. essentially. in. early. incubation. times,. within. 5. days.. This. finding. was. in. agreement. with. the. higher.
. cellulose.mass.observed.at.an.early.incubation.time.in.the.media.containing.
mixed.sugars.compared.to.the.medium.containing.glucose.only,.as.shown.in.
Figure 11.2a..The.level.of.GlcNAc.incorporated.after.7.days.was.in.the.range.
of. 0.03–0.36. mole%,. depending. on. the. amount. of. nonradioactive. GlcNAc.
present.in.the.culture.medium.and.the.type.of.starter.culture.used.
tions.(decreasing.glucose.concentrations).in.the.culture.medium..The.presence.of.high.GlcNAc.concentrations.with.a.concomitant.decrease.in.glucose.
content. may. limit. the. activity. of. cellulose. biosynthesis.. Therefore. the. time.
course.of.cellulose.production.in.the.medium.containing.a.high.concentration.
of.nonradioactive.GlcNAc.(M0020-0416B).showed.a.lower.profile.than.that.of.
lation..In.addition,.the.effect.of.the.type.of.starter.culture.on.GlcNAc.incorporation.was.observed.in.the.glucose.GlcNAc.1010.and.1604.media..The.starter.
cultures.containing.the.same.sugar.content.(e.g.,.inoculation.of.M1604.starter.
culture. into. 1604. medium). led. to. higher. amounts. of. GlcNAc. incorporation.
than.inoculums.from.the.medium.containing.GlcNAc.only.(i.e., inoculation.