Transcript Penicillium chrysogenum

Biotechnology –
Biotechnological techniques
1. Use of micro-organisms
2. Industrial production of enzymes
3. Tissue cultures
Industrial Production of Enzymes
 Use of micro-organsims
 Production of enzymes
 Product recovery
Use of micro-organisms
Enzymes have many applications within
industry e.g. food and drink industries and
textile industries
Naturally occurring enzyme production
 Cellulases
 Source is bacteria
 Used in laundry industry for fabric softening
and as a detergent
 Pectinase
 Source is fungi
 Used in wine and fruit juice industries in
pressing and clarification of juices
Use of micro-organisms cont…
 Amylases
Sources – fungi or bacteria
Used in paper making, as sugar syrups
(sweeteners) and to degrade stains on
cloths
See table 5.2 for further examples of
enzymes produced by microbes
Use of micro-organisms cont…
 Manipulation of micro-organisms to
produce enzymes
 Chymosin (AKA rennin)
 Chymosin is used in cheese manufacture to
clot the milk creating solid curds (and liquid
whey which is drained)
 Lactic acid also helps clot the milk
 Traditionally chymosin comes from the
stomach lining of calves
Use of micro-organisms cont…
 Fungi have been used to produce forms of
protein-clotting enzymes as a substitute for
chymosin
 The best solution is the cloning of chymosin
gene in E. coli
 Gene for the enzyme is removed from the
source
 Placed in plasmid and inserted in E. coli
 Microbe is cultured in a fermenter
 Enzyme removed and purified
Use of micro-organisms cont…
 Cloned chymosin is
 Of consistent quality
 Acceptable to vegetarians and people with
religious objections to eating calf derived
products
 Produced on a large scale
Production of enzymes
 Enzymes are produced in industrial
quantities by growing the micro-organism
in fermenters
 Remember to consider the following when
using fermenters







Sterility (pure culture)
Nutrients
Oxygen
pH
Temperature
Anti-foaming agents
Time
Products
Microbial products can be classified as either
primary or secondary metabolites.
Primary metabolites
 Produced by metabolic activity that is essential
to cell survival
 Produced during the exponential growth phase
 Examples
 Ethanol (bakers yeast)
 Citric acid (Aspergillus)
 Some enzymes
Products cont…
 Secondary metabolites
 By-products of metabolism not essential
to immediate cell survival
 Produced during the stationary phase
 Examples
 Antibiotics (e.g. Penicillin by Penicillium
chrysogenum)
Product Recovery
The majority of enzymes are produced
in an extracellular form by the microbe.
Enzymes are separated from the
microbes, they can subsequently be
concentrated and purified
Product Recovery
(Table 5.1, p.101)
 Separation - the removal of enzymes
from cells, proteins, other metabolites
and growth media
 Flocculation
 Addition of a chemical that causes the
enzyme to precipitate
 Filtration
 Centrifugation
 Spinning solution at high speeds which
separates products according to mass
Product Recovery cont…
 Concentration
 Ultrafiltration
 Filtration through a semi-permeable
membrane that only allows very small
molecules through
 Vacuum Evaporation
 Pressure of the culture is lowered until the
water boils at room temperature
 Water evaporates concentrating the product
Product Recovery cont…
 Purification
 Chromatography
 The analyte (substance to be purified) is
mixed with a solvent
 The analyte is separated according to its
properties and the style of chromatography
used
Past Paper Questions




2005
2003
2006
2005
Q1
Q1
Q3
Q3