BIOTEHNOLOGYPROCESSING PRINCIPLE

What is biotechnology?

• The Office of Technology Assessment of the US Congress defined as:

“Any techniques that uses living organisms or substances from those organisms, to make or modify a product, to improve plants or animals, or to develop microorganisms for specific uses.”

Why Biotechnology Such A Big Deal?

• The benefits of biotechnology may be discussed under 6 major categories:

1. Agriculture (crop, livestock).2. Industry (ethanol, biofuel, bioplastic).3. Health/medicine (diagnostic tool, vaccine)4. Environmental (bioremediation, disease

resistant cultivar)5. Forensic (crime, paternity disputes)6. Advancement of knowledge

What is a bioprocess?

• An industrial operation in which living systems are used to transform raw materials (biological or nonbiological) into products.

• It is a multidiscipline (biochemistry + chemical engineering + biotechnology) area.

• Process to use biology system in commercial scales.

Biotechnology can be bring into bioprocess because:

1.The present of engineering innovation:- exp. genetic engineering, discovery of site-

specific enzyme cleavage of DNA by restriction endonucleases in bacteria is the key to DNA manipulation.

2. The development of appropriate enabling technologies:

- Polymerase chain reaction (PCR) technology- Blotting technology- Fermenter technology

3.Economic opportunity- Arise from identifiable potential benefit

that may accrue to society from development of a product.

KEY STEPS IN BIOPROSES ENGINEERING

1. Pretreatment2. Bioreaction3. Downstream processing

pretreatment

Suit raw material into process

equipment

Design of process Equipment

According to Physical & chemical

properties

Environment factors-physiologically

tolerance of the organism

and enzymes.

Bioreaction1. Bioreactor fluids2. Media sterilization3. Growth media4. Microbial growth5. Mirobial culture systems in bioreactors6. Bioreactors

1. Bioreactor Fluids- Medium in which a bioprocess occurs is

usually a liquid or slurry.- two main kinds of biofluids and slurries used.i. Newtonian fluidsii. Non-Newtonian fluids

2. Media Sterilization- To initiate specific microorganisms for a

specific purpose.- Usually filter sterilization or heat sterilization.- Heat sterilization may be accomplished in

batch sterilization or continuous sterilization.

3. Growth Media- Formulated to maintain microbial growth

for economic production of the target products.

- Should consists basic components such as carbon source, nitrogen source, minerals, vitamins, micronutrients, hormones and oxygen.

- May contain additives that facilitate the process e.g antifoams.

4. Microbial Growth- Progresses through four basic phases (lag,

exponential, stationary and death).- Usually 5 to 10 percent by volume of microbial

suspension in a rapid exponential growth phase may be used.

5. Microbial Culture System in Bioreactors- Grown in three basic ways:1. Batch fermentation2. Fed-batch fermentation3. Continuous fermentation.

6. Bioreactors (will be discussed further)- Designs- Mode of operation

Downstream Processing- To retrieve, purify and pack products for use of

sales.- Involves a number of processing.1. Solid-liquid separation- To separate cells (solid) from the liquid.- Commonly used: centrifugation and filtration.2. Cell disruption- Extracellular product: the cells are discarded

and the medium is concentrated and purified.- Intracellular product: cells have to be disrupted

using nonmechanical or mechanical method.

i. Nonmechanical methods- Using various chemicals, including alkali,

organic solvents, and detergents.- Also some enzymes such as lysozyme, EDTA,

β-1,3-glucanase, mannase and chitinase.- Other physical methods are osmotic shock and

pressure.ii. Mechanical methods- Two catagories: solid shear and liquid shear.- Solid shear: grinding of frozen cells through

narrow gaps under high pressure.- Liquid shear: acceleration of the suspension at

a high velocity and under high pressure.

3. Precipitation- To convert the soluble protein product to

insoluble form.- Commonly used is salting-out technique

using anions and cations.4. Chromatography- To separate components of mixtures

based on their differential physiochemical interaction and a stationary phase.

- The stationary phase is a solid packed in a column by porous and hydrophilic substances like agarose, cross-linked polyacrylamide, and cellulose.

5. Drying- Required for safe-storage, packaging, and

transportation.- Dehydration is used for vaccines,

enzymes, pharmaceuticals and others.- For thermolabile products or biologically

active, spray-dried or freeze-dried.

References:

1. Acquaah, G. (2004). Understanding Biotechnology:An Integrated and Cyber-Based Approach. Pearson-Prentice Hall.

B. Mode of cells growthi. Immobilized cell systemii. Suspension cultures

Immobilized cell systemAdvantages:1.Provides high cell concentrations2.Provides cell reuse 3. Eliminates cell washout problems at high

dilution rates4. Allows high volumetric productivities.

5. Provide favorable microenvironmental conditions for cells, resulting in better performance of biocatalytics.

6. In some cases, improves genetic stability7. Protection against shear damage.Limitation:1.The interest product should b excreted by

the cells.2.