Industrial microbiology

Transcription

1 Industrial microbiology pp , , , Ed van Niel

2 We are here Industrial microbiology biotechnology Why the increased interest Microbiological versus chemical processes Type of fermentation processes The fermentation itself Microbial growth & product formation Metabolic engineering

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4 We are here Industrial microbiology biotechnology Why the increased interest Microbiological versus chemical processes Type of fermentation processes The fermentation itself Microbial growth & product formation Metabolic engineering

5 Petroleum-based to Bio-based chemicals to......reduce global warming!...provide energy for transportation district heating electricity

6 Secondly: 200 ys 40 ys 60 ys ~ 200 ys Search for alternatives -Sustainable -Renewable (ecological balance) (regenerate the sources)

7 Biomass as carbon & energy source Organic wastes (agriculture, domestic, industry) Energy crops (but: fertilization) Forest Algae & waterplants Lignocellulosic biomass: - Majority of biomass - No competition with food or feed

8 Biomass value-pyramid

9 Selling prices versus Concentration

10 Biomass conversion technologies Biomass Physico-Chemical Bio-Chemical Thermo-Chemical Biodiesel production Anaerobic digestion Pyrolysis Hydrolysis/Fermentation Gasification Combustion Liquefaction

11 For fermentations... Sugar/starch must be replaced by Lignocellulose Glucose/Maltose/Sucrose Glucose/Mannose/Galactose Xylose/Arabinose

12 Lignocellulose composition Sugars (hemi)cellulose lignin (%) Brazil: sugarcane US: corn Sweden: wood Raw material Xylan (Xylose) (%) Arabinan (Arabinose) (%) Birch 19 - Spruce 6 1 Wheat bran Corn stover 19 3 Corn cob hulls Grass 16 5 Hayn et al. (1993) In: Bioconversion of forest and agricultural plant residues. pp

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14 LU Biofuels concept Book hyperlinks_version_.pdf

15 Biorefinery in practice: Depends on: -What biomass source -Where is it growing (location) Net energy = Energy(out) Energy(in) For Sweden But little bit of microbiology sofar...

16 We are here Industrial microbiology biotechnology Why the increased interest Microbiological versus chemical processes Type of fermentation processes The fermentation itself Microbial growth & product formation Metabolic engineering

17 Biotechnology in process industry

18 Biotechnological processes Renewable raw materials Specific reactions Neutral ph Low temperatures Low ion strength (osmolarity) No toxic solvents HUGE quantities of H 2 O (dilute streams)

19 Type of (micro-)organisms & products Cells Bacteria Yeasts Filamentous fungi Plant cells Mammalian cells Insect cells Products Amino acids Organic acids Nucleotides Vitamins Polysaccharides Antibiotics Insulin & other hormones Biosurfactants Enzymes Platform chemicals (for chemical industry): Succinate 1,3-Propanediol Itaconic acid Fuels (EtOH, butanol, CH 4, H 2 )

20 Type of fermentation processes Biotransformation (Chemical industry) Biomass & enzyme production Food fermentations (e.g. Beer/Vinegar/Dairy) Fine chemicals (e.g. Pharmacy) Bulk chemicals (e.g. Lactic acid/ethanol)

21 Example of a biotransformation Stereo-specific - no toxic solvents - no by-products - 1 step

22 Microbial biomass production Yeast Quorn How will you grow these organisms, if biomass is the product?

23 Example of enzyme application: Soap

24 Vinegar: food fermentation C 2 H 5 OH + O 2 CH 3 COOH + H 2 O Acetobacter & Gluconobacter species Frings Acetator: high productivity

25 Various definitions of Fermentation 1. Any process involving the mass culture of microorganisms (aerobic or anaerobic) 2. Any biological process that occurs in the absence of O 2 3. Food spoilage 4. The production of alcoholic beverages 5. Use of an organic substrate as the electron donor and acceptor 6. Use of an organic substrate as an electron donor, and of the same partially degraded organic substrate as an electron acceptor 7. Growth dependent on substrate-level phosphorylation

26 Physiologist view on fermentation definition Glucose G6P 1 For instance Lactococcus lactis: Lactic acid production (Primary product) Definitions 5 & 6 in previous slide DHAP ADP ATP ADP ATP F6P FBP GAP 2 1,3-DPG PEP 5 3 PYR AcCoA ATP AD P + NAD NADH CoA HCOO - P i 4 2 NADH 6 Lactate 7 Acetate ADP ATP Ethanol

27 We are here Industrial microbiology biotechnology Why the increased interest Microbiological versus chemical processes Type of fermentation processes The fermentation itself Microbial growth & product formation Metabolic engineering

28 Industrial fermentation media Influences cost price of product! What about Yeast Extract?

29 Conventional industrial bioreactor: Continuous stirred tank reactor (CSTR) -Oxic & anoxic conditions -Nutrient additions -Sample taking -Fermentation monitoring

30 Other ways of fermentation - May have lower operating costs - Special growth conditions for maximized product formation

31 We are here Industrial microbiology biotechnology Why the increased interest Microbiological versus chemical processes Type of fermentation processes The fermentation itself Microbial growth & product formation Metabolic engineering

32 Microbial growth curve in batch mode What happens in each phase? - Growth-limiting nutrient - Maximum specific growth rate (μ MAX )

33 Exponential growth or Logarithmic growth N t = population at time t N 0 = initial population n = number of generations at time t N t = N 0 2 n log N t = log N 0 + n log 2 n = (log N t - log N 0 )/ log 2 k = n/t (number of generations per unit time) If t = 1 h; then k = number of generations/h

34 Biomass concentration Growth rate determination - alternative In practice: t 1 t 2 t g or τ Time (min) Generation or doubling time = t g or τ Theoretical: dx/dt =µx 1/X dx = µ dt ln (X-X 0 ) = µ (t-t 0 ) with t 0 = 0 ln (X/X 0 ) = µ t (Eq. 1) X/X 0 = exp (µ t) X = X 0 exp (µ t) Generation time (t g ) when: X = 2 X 0 add this to Eq. 1: ln (2 X 0 /X 0 ) = µ t g ln 2 = µ t g or: t g = ln 2/µ

35 Continuous culture F (ml/h) V (ml) Change = In + Accumulation - Out dx/dt = 0 + µx - DX dx/dt = 0 = (µ - D)X Thus µ = D D= f/v = dilution rate (1/h) Steady state: Change = 0

36 Primary & Secondary metabolites Primary metabolite: Produced during growth Secondary metabolite: Produced after completion of growth Or after growth limitation Depends on: - Organism - Desired product

37 Secondary metabolite production (Example 1)

38 Secondary metabolite: Glutamic acid (Example 2) Growth: using glyoxylate bypass (Biosynthesis precursors) After growth: production of glutamate

39 We are here Industrial microbiology biotechnology Why the increased interest Microbiological versus chemical processes Type of fermentation processes The fermentation itself Microbial growth & product formation Metabolic engineering

40 Principle of Metabolic Engineering Courses in this field: Gene technology, KBK 041 Metabolic Engineering, KMB 040

41 Principle of genetic engineering -Bring in foreign DNA material (heterologous gene expression) - Overexpress own genes - Knock out genes Why is it not wise to use plasmids in the industrial process?

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44 Solutions to Mindmap 0 Lignocellulosics White Red Green Biotechnology Oil replacement Climate change Interest Biomass source Organic waste Energy crops Forrest Algae Waterplants Biomass value pyramid Biotransformation Biomass & enzymes Food fermentation Fine chemicals Bulk chemicals Metabolites Primary Secondary Cells & products Industrial microbiology Industrial process Conversion process Media Reactors Batch/continuous Growth kinetics GMO Metabolic engineering Selling prices Physical-chemical Thermo-chemical Biochemical Fermentations Definition Biorefinery concept

45 Extra info

46 Industrial microbiology biotechnology White Biotechnology Industrial Biotechnology Red Biotechnology Health Care Biotechnology Green Biotechnology Agricultural Biotechnology