biochemical Engineering good introduction

1. Biochemical Engineering
Dr. Amyl Ghanem
Department of Chemical Engineering
Dalhousie University

2. Outline
• What is biochemical engineering?
• The catalysts
• Relationship to engineering
• Historical perspective: penicillin
• The industry: facts
• The industry:
• Food, beer and wine
• Industrial chemicals
• Pharmaceuticals

3. Some definitions….
• Biotechnology: use or development of methods of direct genetic
manipulation for a socially desirable goal. Sometimes a broader
definition is used, where biotechnology is applied biology.
• Biomedical Engineering: engineering on systems to improve human
health
• Bioengineering, biological engineering: work on medical or
agricultural systems, draws on electrical, mechanical, industrial and
chemical engineers.
• Biochemical Engineering: extension of chemical engineering
principles to systems using a biocatalyst to bring about desired
chemical transformation.

4. The story of penicillin
Alexander Fleming's photo of the dish with
bacteria and Penicillin mold, 1928

6. The story of penicillin
1928 1940’s
Discovered by
Alexander Fleming
Chemical synthesis
proved to be too difficult
Fermentation
route was chosen
Efforts to increase production
•cell line selection
•medium optimization
•process development
Full scale production
15+ years

7. Biocatalyst: cells and enzymes
10-20 mm 1-5 mm

8. Enzyme:
Acetylcholinesterase
size range in nm
E + S E-S E + P

9. Typical chemical processing
A
B
A+B P
P
A
B
temperature
flowrate
A
P
B
Reactor Separation

10. Cell as a bioreactor
Product :
cells
small molecule
enzyme
A
P
C
D etc.
?
Reactor inside a reactor Separation
reactor
A
P
cell
B
C
D
E P
A

11. Bioprocesses are “special”…….
• Cells are living organisms that require specific conditions
for growth, production
• Cells grow in culture medium (nutrients) that may
support other cell types (contamination)
• Bioproducts are often sensitive to external conditions (T,
pH) and can easily be destroyed (separations)
• Product is generally very dilute in bioreactor medium
• Many byproducts in medium to remove

12. ….but they have their advantages!
• Cells will often perform reactions that are too difficult to
do synthetically (penicillin)
• Cells can turn basic nutrients (for example, agricultural
waste) into valuable products
• Amazing diversity of products from cells
• Cells can be modified to increase product diversity even
more!
• Enzymes are highly specific catalysts with high catalytic
power

13. Industry
B.Sc. M.S. Ph.D.
2000 1991 2000 1991 2000 1991
Chemical 26.7 43.7 24.1 38.1 28.4 46
Fuels 12.6 21.2 8.5 16.1 7.6 15.3
Electronics 15.6 2.4 22.8 3.2 19 4.8
Food/Consumer Products 11.4 7.2 4.5 4.5 2.8 5.6
Materials 3.3 2.7 7.1 5.8 6.2 5.6
Biotech and Related
Industries 6.9 3.1 14.7 7.7 19.4 4
Pulp and Paper 2.4 5.1 1.3 3.2 0.9 0.8
Engineering Services 9.8 8.2 10.7 14.9 6.6 11.3
Business Services and
Other*
11.2 6.4 6.3 6.4 9 6.5
AIChE Career Services Dept, 8/25/00
Engineering Employment Trends –

14. Industry in Canada: Biotechnology
• 358 Biotech companies in Canada in 1999
• $1.9 billion in revenue
• 7695 people employed
• 70% are located in the health or agri foods
sectors
• more than 2500 biotech patent applications
every year in Canada

15. Industry in Canada: Bioproducts
Firms that produce fuels, chemicals, materials and
specialty products using biological feedstocks and
bioprocesses
ex. alcohol from agricultural and forest feedstock, enzyme
production companies
•75-100 companies that undertake R&D and
manufacturing
•$100-150 million in sales each year
•1500-2000 people employed
•Very young industry!!

16. Industry in Canada: Medical Devices
• 800 manufacturing firms in 2000 (90%
Canadian-owned)
• 3.1 billion in revenue, 1.6 billion of which
were exports
• 18,000 people employed
• ex) cardiovascular devices and treatments
such as heart valves and ECG systems
• in vitro diagnostics; imaging; dental
implants and materials

17. Industry in Canada: Chemicals
• In 2000, there were 1,200 establishments
operating in Canada.
• They employed approximately 72,500
employees.
• Canadian shipments in 2000 were valued
at $30.2 billion

18. Industry Focus: Food and beverage

19. Industry Focus: Food and beverage
Fermentation Products
• cheese
• soy products
• yoghourt
• wine, beer
• bread
Enzymes
• adjust food flavour
• adjust food texture
• improve nutritional
quality
• high fructose corn
syrup

20. Fermentation
• A form of anaerobic respiration occurring in certain
microorganisms (ex. yeasts)
• Alcoholic fermentation is a series of biochemical
reactions by which pyruvate is converted to ethanol and
CO2.

21. Metabolic pathways in e.coli

22. C6H12O6 → 2 C2H5OH + 2 CO2
• Common yeast saccharomyces cerevisae used in making wine,
beer, bread by above reaction.
• Different strains of yeast can tolerate different alcohol
concentrations.
• Theoretically, 180 g of sugar will produce 92 g of ethanol
Actual yield is only 84.6 g of ethanol
• EtOH (20C) = 0.789 g/mL
• volume of ethanol = 84.6 g x mL = 107.2 mL
0.789 g
• volume of the alcohol and water contracts by 0.7% so
107.2 mL x 1.007 = 108 mL for an overall alcohol
concentration of 10.8% (v/v:108/1000).

24. • Brix (B0) is a density measurement that indicates the
percentage of sugar in 100 g of a sugar-water solution.
Brix can be calculated by:
• Brix = [g sugar/(g sugar + g water)] x 100
• Brix units can be used to predict the alcohol content in
wine.
• % potential alcohol (v/v) = 0.57 x Brixinitial

25. Beer making
• Malting: grains (barley, rice) are steeped in water until
germination and then dried before a plant develops. The starches in
the grains get converted to sugars by enzymes.
• Brewing: finely ground malt is turned into a sweetened liquid
by adding warm water added and heating to around 75o where the
sugars get dissolved. Grain is filtered out, and its boiled for
sterilization and concentration (wort)
• Fermentation: the yeast turns the sugar in the wort into
alcohol, a process that takes about 10 days.

26. Wine making
(1) Yeast Proliferation - aerobic
oxygen is needed to sterol production
increased yeast robustness
(2) Initial Fermentation - anaerobic
sugar is converted to alcohol
duration times typically 5 - 12 days
(3) Secondary Fermentation - malolactic
lactic bacteria metabolize malic acid to lactic acid
lowered acidity and wine “softening” occurs
very typical for red wines

27. Process flowsheet for wine

28. Factors affecting yeast fermentation
• Yeast Species
• Temperature
• Sugar concentration
• pH
• Vitamins
• Sulfur dioxide (SO2)

29. Industry Focus: Textiles

30. Stone washing denim
Denim is faded by
abrasive action of
pumice stones
Indigo dye adheres
to denim surface
Cellulase enzyme
removes some of the dye
by partially hydrolyzing the
cotton surface
•new looks
•lower costs
•shorter treatment times
•less solid waste
•weakens the fabric
traditional
method
new method

31. Detergents
• Detergent industry is the largest single market for enzymes
at 25 - 30% of total sales
• Dirt comes in many forms and includes proteins, starches
and lipids (fats and oils)
• proteases, amylases, lipases are enzymes used in
detergents
• enzymes allows lower temperatures and less agitation for
washing
Inner core of enzyme plus
preservative bound with CMC
Protective waxy coat that
disperses in the wash

32. Industrial Chemicals
Examples:
• organic acids produced from Aspergillus
niger, citric acid used in soft drinks
• Xylanase used for wood pulping and
bleaching

33. Agricultural
Examples:
• Recombinant bovine somatotropin (bST)
for increasing milk production
• Bio-insecticides for crop protection
• Phyto-vanilla(tm) flavor derived from tissue
culture

34. Environment
• Cleanup of hazardous waste sites using
bacteria that feed on pollutants
• Bacteria used for bio-remediation
• wastewater treatment
• Biosensors: use biological activity to
detect toxic substances
• RIS® Water tests: antibody based kit to
detect low level of solvents such as
benzene

35. Fuel ethanol

36. Industry Focus: Pharmaceuticals

37. Phase II clinical trials
in 100 to 300 patients
The Drug Development and Approval Process
The drug discovery and approval process takes and average of
15 years and costs almost $400 million
source: Pharmaceutical Research and Manufacturers of America, Washington DC, 1996
Discovery of
a promising
compound
Preclinical testing
in animals
Phase III clinical trials
in 1000 to 3000
patients
FDA review and
approval
Drug may be
prescribed by
physicians
1 year
3 years 19 months
6.5 years 2 years
Phase I clinical trials
in healthy volunteers

38. Products
• Small molecules and metabolites
• antibiotics
• Protein drugs
• Vaccines
• Antibodies, Monoclonal antibodies (MAb)
How?
Recombinant DNA technology means bacteria and
yeast can produce human proteins like insulin

39. Penicillin fermentation

40. 2005 World market for biopharmaceuticals
Enbrel Rheumatoid arthritis
and psoriasis
Amgen/Wyeth $3,657 US
mil
Procrit/Ep
rex
Stimulation of red blood
cells for treatment of
anemia in HIV patients
Johnson&Johnson/Ortho
Biotech
$ 3,324 US
mil
Aranesp Stimulation of red blood
cells for treatment of
anemia associated with
chronic renal failure
Amgen $ 3,273 US
mil
Rituxan Leukemia and non-
Hodgins lymphoma
Genentech/Roche/Biogen $ 3,154 US
mil
Remicade Rheumatoid arthritis
and Crohn’s disease
Johnson&Johnson/Centoco
r/Schering Plough
$ 2,535 US
mil

41. Epogen Stimulation of red blood
cells for treatment of
anemia associated with
chronic renal failure
Amgen $ 2,455 US
mil
Neulasta Stimulation of
production of white
blood cells for protection
against chemotherapy
complications
Amgen $ 2,288 US
mil
NeoRecor
mon/Epog
in
Stimulation of red blood
cells
Genentech/Roche/Chugai $ 1,710 US
mil
Herceptin Breast cancer Genentech/Roche $ 1,629 US
mil
Avonex MS Biogen IDEC $ 1,543 US
mil

42. Monoclonal antibodies

44. New challenges….
Increasingly, bacteria
and yeast cannot
correctly form the
human protein:
animal cell culture
ex) mouse cells
require even more
careful treatment
Large quantities???

45. Opportunities for you?
The Bioproducts industry “needs staff that
bridge the key disciplines of biology,
chemistry and engineering”
Canada’s Innovation Strategy , 2001
Government of Canada
Bioproducts Sector Profile

46. Main Issues
• Types of reactors to provide high oxygen transfer
• Appropriate cell and medium selection
• Sterilization and maintaining sterility, no cross
contamination
• In pharma, product purity and quality impedes process
change
• Cells and molecules are sensitive to extreme conditions
• Growth rate and reaction rates are small
• Product is usually very dilute
• Non traditional methods of separation
• Often batch operations