Producing large beads from alginate

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Producing large beads from alginate

• Principle and equipment

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Principle
Alginate solution divalent cations (Ca, Ba,
etc.) solidified matrix (gel-like material)
If alginate solution is forced into a droplet
shape, the result will be a solid bead (sphere)
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Producing beads in small quantities

• The alginate solution is dripped, one drop at the
  time from a large syringe into solution of
  calcium chloride
• The beads are instantly formed in the CaCl2
  solution

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One more time to get the idea right
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If all you need are a few grams of beads for
your experiments

• The method just shown is ideal and you need not
  read further.
• However.

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If your experiment requires large quantities of
beads (one or more liters)

• You will find the syringe method very tiresome,
  especially when hard beads are needed when
  employing highly viscous alginate solutions
• Some equipment is needed

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Equipment for producing large beads (2-4 mm dia.)

• This is essentially a showerhead metal container,
• With specially-designed nozzles.
• Bead form by the force of gravity.

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In real life, the device looks like this.
Alginate solution
Droplets
Nozzle plate
Formed beads
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It can be made in a smaller size (or larger).
Nozzle plate
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Immobilization (entrapment) of one bacterial
species and co-immobilization of two (or more)
microorganisms inside the bead
Chlorella

Azospirillum
Alginate
co-immobilization
3 mm
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Potential use of large beads

• Industry (production of microbial compounds)
• Wastewater treatment (removal of contaminants)
• Agriculture (production of bacterial inoculants)

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Industry (fermentation)
Microorganisms entrapped in alginate are often
grown in large fermentation vats, similar to the
vat pictured at left. The products they produce
are harvested, while the beads remain inside the
vat.
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Wastewater treatment
Something for the future-- Large-scale treatment
by immobilized and co- immobilized microorganisms
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Agriculture (bacterial inoculants) before sowing
Beads
Seeds
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Agriculture (dry alginate beads sowed in a wheat
field)
BEADS
SEEDS
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Other applications?

• The sky is the limit
• Use your imagination

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Some unexpected benefits

• It does not require human energy, let alone paid
  energy.
• It is accepted technology, published in most
  scientific journals. (Your brilliant paper will
  not be rejected on the basis of an untried
  method.)
• As an environmentally-friendly technology, using
  it will make you look good.
• Have fun..