TEKNIK SEPARASI
OVERVIEW OF BIOSEPARATIONS
• Up to 90% of new product cost is in downstream processing.
• More than 60% of the cost of third and fourth generation antibiotics is in purification.
Bioseparations are elaborate and expensive.
For recombinant DNA
fermentation products,
downstream processing can
account for 80 to 90% of the
overall processing cost.
BIOSEPARATION COST
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To improve the design of bioseparations, the following questions should be answered:
(1) What is the value of the product?
(2) What is an acceptable product quality?
(3) Where is the product in each process stream?
(4) Where are the impurities in each process stream?
(5) What are the unusual physicochemical properties of the product and the principal impurities?
(6) What are the economics of various alternative separations?
BIOPRODUCTS
BIOPRODUCTS
Bioproducts can be broadly classified into three categories:
small molecules, large molecules, and particulate products.
There are three corresponding separation procedures for purifying them.
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(1) Separation of insolubles
* Objectives: remove or collect cells, cell debris, or other particulates
* Typical operations: filtration, centrifugation
* Relatively little product concentration or improvement of product quality occurs.
Most bioseparations have four similar steps:
Most bioseparations have four similar steps (2/3):
(1) Separation of insolubles (2) Isolation of products
* Objectives: remove materials of widely divergent properties compared to the desired product
* Typical operations: extraction, adsorption, ultrafiltration, precipitation
* Appreciable concentration and product quality increases usually occur.
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Most bioseparations have four similar steps (3/3):
(1) Separation of insolubles (2) Isolation of products (3) Purification
* Objectives: remove impurities of similar chemical functionality and physical properties
* Typical operations: chromatography, affinity
methods, fractional precipitation, electrophoresis
(4) Polishing
* Objectives: remove liquids
* Typical operations: drying, crystallization (not always possible)
Processing profile of antibiotics:
Product Step Typical Process Conc.
(g/L)
Quality (%) Harvest broth
Fermentation 0.1-5 0.1-1.0
Separation of insolubles
Filtration 1.0-5 0.2-2.0
Isolation Extraction 5-50 1-10
Purification Chromatography 50-200 50-80 Polishing Crystallization 50-200 90-100
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Separation principles used in various recovery steps:
Size
• Filtration• Membrane
Densi ty
• Sedimentation
• Centrifugation
• Flotation
Diffusi
vity
• MembraneShape
• Filtration
• Sedimentation
Polari ty
• Extraction
• Chromatography
• Adsorption
Solub ility
• Extraction
• Precipitation
• cristallisation
Elc.
charge
• Adsorption
• Electrophoresis
Volatil ity
• Distillation
• Pervaporation
Bioseparation Technique
• According to product characteristic
• Considering selectivity and productivity
• Selectivity: main product/byproduct
• Productivity: main product/time
Bioseparation Technique
• Low selectivity-high productivity
• Cell disruption
• Precipitation
• Centrifugation
• Extraction
• Leaching
• Filtration (+micro, ultra)
• Adsorption
• High selectivity-low productivity
• Ultracentrifugation
• Chromatography
• Affinity separation
• electrophoresis
EXAMPLE
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Process for ethanol production from fermentation:
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Manufacture of citric acid:
Penicillin production:
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Production of an intracellular enzyme:
Processing scheme for recombinant insulin:
(Inclusion Body)
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Processing scheme for recombinant insulin (2/2):
