Figure 3.1
Culture
medium
Steam
Water inlet for
cooling/heating
(for sterilization)
Temperature
regulation
Air (steril)
Water outlet
pHcontrol
Exhaust gas
Stirrer
46
Bacterial Cellulose
Figure 3.1
(See color insert.).Example.for.a.typical.deep-tank.fermenter.based.on.the.stirred.tank.reactor.
(STR).concept..Figure.adopted.from.http://www.chemgapedia.de.
by. several. process. parameters.. In. 1989. Williams. and. Cannon. discovered. a.
change.in.thickness.of.the.flat.BNC.by.the.use.of.different.Gluconacetobacter.
strains..Further.control.of.the.thickness.and.size.of.BNC.can.be.achieved.by.
variation.of.the.volume.of.the.culture.medium.(Udhardt.2004),.the.cultivation.
time.(Borzani.and.De.Souza.1995),.and.the.cultivation.vessel.(Levy.et.al..2004;.
Tamura.et.al..1999)..Static.cultivation.is.described.in.detail.later.in.this.chapter.
Besides.BNC.production.under.static.conditions,.there.are.a.large.number.
of.other.cultivation.types..Cultivation.under.shaking.and.stirring.(Watanabe.
and. Yamanaka. 1995),. as. well. as. several. modified. production. procedures.
based.on.these.techniques.(Chao.et.al..2001b;.Wu.et.al..2001),.are.the.most.
important.. In. Figure 3.1,. an. example. of. a. typical. deep-tank. fermenter. for.
aerated.cultivation.is.shown..The.reactor.consists.of.a.vessel.typically.made.
from.stainless.steel.or.glass,.a.stirrer,.inlets.and.outlets.for.culture.medium.as.
well.as.air.or.oxygen,.a.cooling.or.heating.jacket,.and.several.control.systems.
for.sensible.process.parameters.such.as.temperature.and.pH.
Agitation.during.the.biosynthesis.results.in.the.synthesis.of.BNC.in.the.form.
of.a.fibrous.suspension,.irregular.masses,.pellets,.or.spheres.(Krystynowicz.
et.al..2002)..The.production.of.individualized.(isolated).BNC.in.defined.sizes.
and.different.surface.characteristics.can.be.controlled.by.the.choice.of.specific.
cultivation.conditions.(Hessler.and.Klemm.2008).
Several.working.groups.have.seen.the.possibility.of.producing.commercial.
quantities.of.BNC.by.agitated.forms.of.cultivation.(Czaja.et.al..2004b)..They.
argue. that. static. cultivation. delivers. only. restricted. BNC. yields. with. the.
Culture
medium
Steam
Water inlet for
cooling/heating
(for sterilization)
Temperature
regulation
Air (steril)
Water outlet
pHcontrol
Exhaust gas
Stirrer
46
Bacterial Cellulose
Figure 3.1
(See color insert.).Example.for.a.typical.deep-tank.fermenter.based.on.the.stirred.tank.reactor.
(STR).concept..Figure.adopted.from.http://www.chemgapedia.de.
by. several. process. parameters.. In. 1989. Williams. and. Cannon. discovered. a.
change.in.thickness.of.the.flat.BNC.by.the.use.of.different.Gluconacetobacter.
strains..Further.control.of.the.thickness.and.size.of.BNC.can.be.achieved.by.
variation.of.the.volume.of.the.culture.medium.(Udhardt.2004),.the.cultivation.
time.(Borzani.and.De.Souza.1995),.and.the.cultivation.vessel.(Levy.et.al..2004;.
Tamura.et.al..1999)..Static.cultivation.is.described.in.detail.later.in.this.chapter.
Besides.BNC.production.under.static.conditions,.there.are.a.large.number.
of.other.cultivation.types..Cultivation.under.shaking.and.stirring.(Watanabe.
and. Yamanaka. 1995),. as. well. as. several. modified. production. procedures.
based.on.these.techniques.(Chao.et.al..2001b;.Wu.et.al..2001),.are.the.most.
important.. In. Figure 3.1,. an. example. of. a. typical. deep-tank. fermenter. for.
aerated.cultivation.is.shown..The.reactor.consists.of.a.vessel.typically.made.
from.stainless.steel.or.glass,.a.stirrer,.inlets.and.outlets.for.culture.medium.as.
well.as.air.or.oxygen,.a.cooling.or.heating.jacket,.and.several.control.systems.
for.sensible.process.parameters.such.as.temperature.and.pH.
Agitation.during.the.biosynthesis.results.in.the.synthesis.of.BNC.in.the.form.
of.a.fibrous.suspension,.irregular.masses,.pellets,.or.spheres.(Krystynowicz.
et.al..2002)..The.production.of.individualized.(isolated).BNC.in.defined.sizes.
and.different.surface.characteristics.can.be.controlled.by.the.choice.of.specific.
cultivation.conditions.(Hessler.and.Klemm.2008).
Several.working.groups.have.seen.the.possibility.of.producing.commercial.
quantities.of.BNC.by.agitated.forms.of.cultivation.(Czaja.et.al..2004b)..They.
argue. that. static. cultivation. delivers. only. restricted. BNC. yields. with. the.