Expanded Bed Technology for High-rate Bioprocesses
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Transcript of Expanded Bed Technology for High-rate Bioprocesses
Expanded Bed Technology for High-rate Bioprocesses
Mike Dempsey School of Biology, Chemistry, & Health Science
Manchester Metropolitan University and Advanced Bioprocess
Development Ltd. (an MMU spin-out company) Bioprocesses? microbes
have a multitude of biochemical and metabolic abilities Escherichia
coli (Bacterium, 1 m long) 6,000 genes 2,000 enzymes. Expanded Bed
Technology
fluid-based processing normally liquid gas-phase possible
processing of liquids pure or solutions grow cells in nutrient
liquid and replace with feedstock or feedstock solution, whilst
retaining cells in bioreactor particulates. Programme Topics
materials processing energy production
waste processing and bioremediation corrosion resistance production
of drugs manufacture of polymers. Programme Topics materials
processing?
oxidation of reduced sulphur minerals to yield sulphuric acid and
dissolved metals. Programme Topics energy production? ethanol
(biodiesel) methane. Programme Topics waste processing and
bioremediation?
liquid organic wastes to methane-rich biogas biological wastewater
treatment. Programme Topics production of drugs? antibiotics
secreted heterologous products? e.g. proteins plant cell
metabolites?. Expanded Bed Technology
method of process intensification 10-fold increase in biomass
concentration 10-fold decrease in bioreactor size fixed biofilm
system no need for biomass recovery & recycle natural
immobilization on glassy coke naturally-adhesive microbes biomass
retention cheap media expanded bed does not clog no backwashing.
Attachment and Biofilm Formation
Ethanol-producing bacterium: Zymomonas mobilis Ethanol-producing
yeasts: Saccharomyces cerevisiae (top)S. diastaticus (bottom)
Particulate Biofilm Technology
fixed film process method of process intensification retention of
biomass by attached growth attachment to support particles microbes
grow as a biofilm formation of particulate biofilms biofilm coke
Biomass Support Medium: Glassy Coke
carbonized bituminous coal light (SG 1.2) carbon-based (90% C + 10%
ash) porous (interconnecting pores: carbon foam) initial
colonisation of pores overgrowth to form complete biofilm sand
heavy (SG 2.65) & non-porous. No Biomass Support Medium? =
unstable Static Bed zero to low flow Expanded Bed (< 100%)
medium flow zero to low flow Fluidized Bed (> 100%) medium flow
zero to low flow high flow Transition from static to expanded bed,
as pump switched on Expanded bed: note retention of bioparticles
Expanded bed: biofilm thickness control Pilot-scale (0.6 m3
expanded bed) Full-scale package plant (10 m3 expanded bed) Enzyme
& Biodiesel Production
Early biofilm-formation in pores of glassy coke:
transesterase-producing, thermophilic bacteria. Fuel Ethanol
production
Ethanol-producing bacterium: Zymomonas mobilis (thick biofilm on
glassy coke) Fuel Ethanol production Fuel Ethanol production
Shewanella putrefaciens bioparticles for wastewater treatment
Biocatalysis. e. g. with mono-oxygenase
Biocatalysis? e.g. with mono-oxygenase? (ammonia mono-oxygenase
producer) Summary generic technology with wide variety of
applications
fluid-based processing liquid (or gas) fluidization of small
particles causes bed expansion attachment of microbes to particles;
growth as biofilm high biomass concentration excellent mixing and
mass transfer highly active biomass high-rate, compact process
technology.