47
Large-Scale Production of BNC
concurrent.use.of.large.surfaces.and.space.demands..By.means.of.an.agitated.
cultivation. in. fermenters,. the. formation. limit. should. be. avoided. and. continuous.production.of.BNC.should.be.feasible.(Ben-Bassat.et.al..1987;.Kouda.
et.al..2000;.Tokura.et.al..1993)..Indeed,.these.cultivation.conditions.can.lead.
to.an.increase.in.BNC.formation.(Krystynowicz.et.al..2002)..But.only.a.few.
Gluconacetobacter strains,.such.as.ATCC.53582,.have.been.found.to.be.suitable.
for.agitated.cultivation.(Toyosaki.et.al..1995)..This.can.be.seen.in.shear.forces.
that.cause.a.reduction.in.BNC.biosynthesis.or.disruption.of.the.bacteria.cells..
In.addition,.a.spontaneous.formation.of.mutations.from.active.bacterial.cells.
to.non-cellulose.producing.is.favored.(Park.et.al..2004)..In.spite.of.the.restrictions.discussed.earlier,.these.agitated.cultivation.methods.possess.their.own.
unique.potential.for.future.industrial.use,.because.other.areas.of.application.
become.possible..The.resulting.BNC.pulps,.filaments,.or.spheres.are.suitable.
as,.for.example,.an.additive.for.papermaking.(Xiu.et.al..2005).and.for.fiber.
reinforcement.of.synthetic.or.biopolymers.(Tomé.et.al.,.2011)..Agitated.types.
of.cultivation.are.described.in.detail.later.in.this.chapter.
Other.cultivation.types.between.static.and.agitated.cultivation.have.been.
developed.as.well..Well-known.examples.are.the.nonstatic.rotating.disk.and.
linear.conveyor.film.bioreactors.used.by.Bungay.and.Serafica.(2000).for.BNC.
generation.for.the.first.time,.or.the.generation.of.BNC.in.tubular.form.developed.by.Klemm.et.al..(1999).
Independent.from.the.cultivation.method.or.the.bacteria.strain,.the.process.of.BNC.generation.can.also.be.influenced.by.a.large.number.of.other.
variables,.including.the.composition.of.the.culture.media.(Heo.and.Son.2002;.
Ishihara. et. al.. 2002;. Seto. et. al.. 1997). and. its. pH. value. (Strobin. et. al. 2003),.
the.temperature.(Coban.and.Biyik.2011).and.oxygen.tension.(Nakajima.et al..
2001),.as.well.as.by.several.additives,.such.as.water-soluble.polymers.(Astley.
et. al.. 2001),. organic. or. inorganic. substances. (Hessler. and. Klemm. 2009;.
Ishihara.et.al..2002;.Yamanaka.et.al..2000),.and.metal.or.metal.oxide.nanoparticles.(Serafica.et.al..2002)..In.all.cases,.the.optimization.of.the.cultivation.
conditions.plays.a.specific.role.during.the.scale-up.of.a.cultivation.process.
from.experimental.(grams.per.day).to.pilot.(kilograms.per.day).or.industrial.
scale.(tons.per.day).
In.addition.to.biological.conditions,.various.technical.parameters.such.as.
sterilization.of.the.equipment,.robustness.and.stability.against.corrosion.of.
the.reactor.material,.equally.distributed.supply.of.air.and.culture.medium,.
and.protection.against.contaminants.must.be.investigated.and.adapted.
Although. a. variety. of. approaches. for. the. production. of. BNC. in. various.
forms.have.been.suggested.over.the.past.20.years,.in.industrial.practice.BNC.
is.still.almost.exclusively.produced.using.static.cultivation.in.shallow.containers. using. minimally. automated. work. processes.. Thus. extensive. commercialization. of. BNC. has. been. hindered. by. the. lack. of. efficient. methods.
and.high.costs.for.the.generation.of.high-quality.BNC.on.an.industrial.scale.
However,. the. testing. and. scale-up. of. ideas. for. efficient. BNC. generation.
continues. unabated. to. overcome. these. hurdles.. For. instance,. Song. et. al..
Large-Scale Production of BNC
concurrent.use.of.large.surfaces.and.space.demands..By.means.of.an.agitated.
cultivation. in. fermenters,. the. formation. limit. should. be. avoided. and. continuous.production.of.BNC.should.be.feasible.(Ben-Bassat.et.al..1987;.Kouda.
et.al..2000;.Tokura.et.al..1993)..Indeed,.these.cultivation.conditions.can.lead.
to.an.increase.in.BNC.formation.(Krystynowicz.et.al..2002)..But.only.a.few.
Gluconacetobacter strains,.such.as.ATCC.53582,.have.been.found.to.be.suitable.
for.agitated.cultivation.(Toyosaki.et.al..1995)..This.can.be.seen.in.shear.forces.
that.cause.a.reduction.in.BNC.biosynthesis.or.disruption.of.the.bacteria.cells..
In.addition,.a.spontaneous.formation.of.mutations.from.active.bacterial.cells.
to.non-cellulose.producing.is.favored.(Park.et.al..2004)..In.spite.of.the.restrictions.discussed.earlier,.these.agitated.cultivation.methods.possess.their.own.
unique.potential.for.future.industrial.use,.because.other.areas.of.application.
become.possible..The.resulting.BNC.pulps,.filaments,.or.spheres.are.suitable.
as,.for.example,.an.additive.for.papermaking.(Xiu.et.al..2005).and.for.fiber.
reinforcement.of.synthetic.or.biopolymers.(Tomé.et.al.,.2011)..Agitated.types.
of.cultivation.are.described.in.detail.later.in.this.chapter.
Other.cultivation.types.between.static.and.agitated.cultivation.have.been.
developed.as.well..Well-known.examples.are.the.nonstatic.rotating.disk.and.
linear.conveyor.film.bioreactors.used.by.Bungay.and.Serafica.(2000).for.BNC.
generation.for.the.first.time,.or.the.generation.of.BNC.in.tubular.form.developed.by.Klemm.et.al..(1999).
Independent.from.the.cultivation.method.or.the.bacteria.strain,.the.process.of.BNC.generation.can.also.be.influenced.by.a.large.number.of.other.
variables,.including.the.composition.of.the.culture.media.(Heo.and.Son.2002;.
Ishihara. et. al.. 2002;. Seto. et. al.. 1997). and. its. pH. value. (Strobin. et. al. 2003),.
the.temperature.(Coban.and.Biyik.2011).and.oxygen.tension.(Nakajima.et al..
2001),.as.well.as.by.several.additives,.such.as.water-soluble.polymers.(Astley.
et. al.. 2001),. organic. or. inorganic. substances. (Hessler. and. Klemm. 2009;.
Ishihara.et.al..2002;.Yamanaka.et.al..2000),.and.metal.or.metal.oxide.nanoparticles.(Serafica.et.al..2002)..In.all.cases,.the.optimization.of.the.cultivation.
conditions.plays.a.specific.role.during.the.scale-up.of.a.cultivation.process.
from.experimental.(grams.per.day).to.pilot.(kilograms.per.day).or.industrial.
scale.(tons.per.day).
In.addition.to.biological.conditions,.various.technical.parameters.such.as.
sterilization.of.the.equipment,.robustness.and.stability.against.corrosion.of.
the.reactor.material,.equally.distributed.supply.of.air.and.culture.medium,.
and.protection.against.contaminants.must.be.investigated.and.adapted.
Although. a. variety. of. approaches. for. the. production. of. BNC. in. various.
forms.have.been.suggested.over.the.past.20.years,.in.industrial.practice.BNC.
is.still.almost.exclusively.produced.using.static.cultivation.in.shallow.containers. using. minimally. automated. work. processes.. Thus. extensive. commercialization. of. BNC. has. been. hindered. by. the. lack. of. efficient. methods.
and.high.costs.for.the.generation.of.high-quality.BNC.on.an.industrial.scale.
However,. the. testing. and. scale-up. of. ideas. for. efficient. BNC. generation.
continues. unabated. to. overcome. these. hurdles.. For. instance,. Song. et. al..