Biochemical Engineering

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

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

5. The story of penicillin

6. Biocatalyst: cells and enzymes

8. Typical chemical processing

9. Cell as a bioreactor

10. 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

11. �.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 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

14. 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!!

17. Industry Focus: Food and beverage

18. 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

19. 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. 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).

23. 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

24. 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.

25. 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

26. Process flowsheet for wine

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

28. Industry Focus: Textiles

29. Stone washing denim

30. 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 Enzymes are used in surprisingly small amounts in most detergent preparations, only 0.4 - 0.8% crude enzyme by weight (about 1% by cost). It follows that the ability to withstand the conditions of use is a more important criterion than extreme cheapness. Once released from its granulated form the enzyme must withstand anionic and non-ionic detergents, soaps, oxidants such as sodium perborate which generate hydrogen peroxide, optical brighteners and various less-reactive materials (Table 4.1), all at pH values between 8.0 and 10.5. Although one effect of incorporating enzymes is that lower washing temperatures may be employed with consequent savings in energy consumption, the enzymes must retain activity up to 60�C. The enzymes used are all produced using species of BacillusEnzymes are used in surprisingly small amounts in most detergent preparations, only 0.4 - 0.8% crude enzyme by weight (about 1% by cost). It follows that the ability to withstand the conditions of use is a more important criterion than extreme cheapness. Once released from its granulated form the enzyme must withstand anionic and non-ionic detergents, soaps, oxidants such as sodium perborate which generate hydrogen peroxide, optical brighteners and various less-reactive materials (Table 4.1), all at pH values between 8.0 and 10.5. Although one effect of incorporating enzymes is that lower washing temperatures may be employed with consequent savings in energy consumption, the enzymes must retain activity up to 60�C. The enzymes used are all produced using species of Bacillus

34. Fuel ethanol

35. Industry Focus: Pharmaceuticals

37. 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

38. Penicillin fermentation

41. Monoclonal antibodies

43. New challenges�. Increasingly, bacteria and yeast cannot correctly form the human protein: animal cell culture ex) mouse cells require even more careful treatment

44. Opportunities for you? The Bioproducts industry �needs staff that bridge the key disciplines of biology, chemistry and engineering�

45. 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