Bi9540 Biotechnology and practical use
of algae and fungi
Lecture 2 – Culturing techniques
Upstream And Downstream Processes
host organism
strain improvement
medium engineering
cultivation upscale
industrial fermentation
culture separation
cell disruption
purification
product
finishing
FERMENTATION TECHNOLOGY
 Production of microbial biomass
 Upstream processing
 Scale
 Laboratory (< 30 L)
 Pilot (< 100 L)
 Semi-industrial (100 - 5,000 L)
 Industrial (> 5,000 L)
http://www.rpi.edu/dept/chem-eng/Biotech-Environ/FERMENT/largest.htm
World largest fermenter
WORLD LARGEST FERMENTER
 Built in 1978 in Birmingham
 Height 200 ft (61 m)
 Diam. 25 ft (7.6 m)
 Volume 736,300 gallons
 3 347 000 L
Construction of bioreactor
Ipellers
Mixing in propelled bioreactor
Rushton type impeller
Impellers
Fermentation process
Culture types
 Batch, fed-batch, continuous culture
Fed-batch
Fed-batch
 Feeding strategy is important to avoid substrate depletion
or overfeeding of the culture
Fed-batch
 Industrial fed-batch fermentation of sugar juice
Fed-batch
 Fed-batch fermentation with yeast cell recycle
Continuous culture
 Influx of fresh medium, efflux of cell culture
 Can be operated for weeks or months
Culture growth
Diauxic growth
 Two substrates in medium
 Fungi and lactose
Microbial growth
 Growth rate
 Oxygen mass transfer
 Nutrient utilization Mass Balances
Potential limiting factors
 Dissolved oxygen tension
 pH
 Temperature, mixing speed
 Nutrient concentration
 Product concentration
 Secondary metabolites
 Population dynamics
 Genomic/plasmid instability
Stirred tank bioreactor
 Most common in biotechnology
 Easy cleaning and parameter control
 Well described scale-up
 Good gas transfer
 Higher investment and maintenance cost
 Mixing is not optimal
 Max volume 1,000 m3
Bubble column
 Low investment cost, no moving parts, even over 1,000 m3
 Easy cleaning, good gas transfer and mixing
 Foaming, difficult condition control
 Limited viscosity
Airlift reactor
 Low investment, no moving parts, easy cleaning
 Good gas transfer
 Loop can be used for cooling
 Foaming, difficult condition control
 Poor mixing
Bioreactor comparison
Single-use bags
Solid state fermentation
 Absence of free water
Solid state fermentation
Solid state fermentation
 Low-cost raw materials
 Easy down-stream processing
 Reduced waste and pollution
 Cost-effective (no water), easy control
 Resembles natural environment of the microbes
Solid state fermentation
Koji fermentation
 Aspergillus oryzae = Kanji 麹
 Traditional Japanese fermentation process
Koji fermentation
 Shōchū production
Cocoa bean fermentation
 Beans are fermented 2-7 days covered with banana leaves
 Without fermentation, there would be no chocolate
Coffee beans skin removal
Fermented tea
 Aspergillus niger, luchuensis
 Pu-erh and some other black teas
Kombucha fermentation
 Variety of fermented black or green tea
 Saccharomyces cerevisiae, Brettanomyces bruxellensis,
Candida stellata, Schizosaccharomyces pombe, and
Zygosaccharomyces bailii
Tobacco fermentation
 Harvested leaves are fire-cured and moistened
 Debaryomyces hansenii is predominant in early stage
 Fermentation can take from weeks to years
Photobioreactors
Photobioreactor vs fermentor
Photobioreactors
Photobioreactors
Photobioreactors
Tubular glass photobioreactor Christmass tree photobioreactor
Plastic plate photobioreactor Horizontal photobioreactor with zig-zag geometry
Outdoor ponds
Maricultures of seaweed
 Marine algae can be
cultured in sea water
Algae-powered houses
 129 bioreactors on south and south-east faces
 Hamburg, Ger