PRODUCTION OF BUTANOL FROM LOWER TERMITE PROTISTS AND
E. COLI FERMENTATION
Team Gold All On My Polypeptide Chain:
Derek Weidlein
Ricky Rodriguez
Michelle Empleo
Michael McClurg
Jerrell Ross
PURPOSE
There is an increase demand for alternative
biofuel.
Utilize otherwise useless plant material for energy
Produce a higher efficiency product
“In 2011, the United
States consumed about
134 billion gallons of
gasoline.”
ETHANOL AS A FUEL SOURCE
One of the cleanest
sources of energy
Established method of
production
Takes away from human
food sources
Low energy density
Absorbs moisture in the air
OUR IDEA: BUTANOL
Clean source of energy
Would mix well with gasoline
Not hygroscopic
Higher energy density than ethanol
High cellulose
feedstock
Cellulose breakdown
with termite hindgut
protists and bacteria
Extract simple sugars
PLAN OVERVIEW
Use genetically altered
E. Coli to ferment sugars
into alcohol product
Distill product to
isolate butanol for use as
biofuel
OUR FEEDSTOCK?
% Cellulose
50
95
63
70
78
71
76
73
Hardwood
Cotton
Flax
Hemp
Henequen
Jute
Ramie
Sisal
Useful or Not?
Useful
Not Useful
Potentially
Potentially
Not Useful In U.S.
Useful
Not Useful
Not Useful
BREAKING DOWN CELLULOSE
Endocellulase-breaks
crystal structure of complex
cellulose (breaks H-bonds)
Exocellulase-cleaves 1
glucose off of 3-ringed
cellulose
Cellobiase-splits 2-ringed
cellobiose into 2 glucose
molecules
Invasive species found in Southeast
Asia (China, Japan, and Taiwan), but
can also be found in the continental
United States, South Africa, and
Hawaii
Grouped in the Lower Termite class
which means it relies on a symbiotic
relationship with protists and
bacteria to complete its metabolic
functions (cellulose breakdown and
glucose fermentation)
TERMITES (COPTOTERMES FORMOSANUS)
DIGESTION OVERVIEW
Some cellulose activity in the salivary glands and midgut of termite, but most
activity is done in the hindgut by the protozoan fauna (full decomposition of
cellulose to glucose), which feed by phagocytosis.
Pseudotrichonympha grassi- largest protozoan that decomposes highly
polymerized cellulose
Holomastigotes hartmannii- breaks down low molecular weight
cellulose
Spirotrichonympha leidyi- smallest protozoan breaks down low
molecular weight cellulose
Trichomitopsis termopsidis- ferments the glucose into acetate, carbon
dioxide, and hydrogen
PROTISTS IN HINDGUT
IN MORE DETAIL
Cellulose-containing product would first be chipped and then
ground as small as possible with machinery
This sawdust would be mixed with water into a cellulose soup
This soup would sit in a large pool where it will be aerated to
maintain an oxygen-rich environment, and inoculated in many
separate locations with about one total gram of p. grassii, h.
hartmannii, and s. leidyi
This mixture would be maintained at a pH of about 6.5, and kept
slightly above room temperature
PROTIST ASSUMPTIONS
Characteristic Assumption
Unit mass 1 protist≈1 nanogram
Doubling time 2 hours
Daily consumption 3.685E-13kg cellulose per protist per day
All assumptions based on typical protists, since we could not find specific information on our protists
1 colony consumes .3685kg wood per day, there are 1,000,000 termites per colony, each termite weighs about 2mg, and “termites can be up to 50% digestive protists and bacteria”
CONSUMPTION RATE VS T IME (UNDER IDEAL CONDITIONS)
0 10 20 30 40 50 600
50
100
150
200
250
300
Rate of Consumption vs. Time
Time (hours)
Rate
of
Consu
mpti
on
(kg c
ell
ulo
se p
er
hour)
EXPECTED YIELD
In order to make about 10,000kg of glucose , we would need about
18.7 metric tons of hardwood feedstock. This translates to about 7
large trees, about 2/3 the capacity of one semi-truck
With a 1g inoculum and an assumed doubling time of about 2 hours,
the protists would be capable of consuming 6200kg of cellulose per day
after the first two days.
Total estimated time to consume cellulose without lag phase or death
phase is about 47.2 hours
1. Rotating drum filtration to
remove the solid non-
cellulose wood components
2. Precipitate acetate via a
sodium salt
3. Filter out the salt product
REMOVAL OF GLUCOSE FROM THE BATCH
Naturally converts glucose
to valine via a pyruvate and
2-Keto-isovalerate
intermediate
We know a lot about E.
Coli’s DNA, so we can add in
new genetic material to
utilize this 2-Keto-isovalerate
intermediate
E. COLI
PATHWAY
Glucose Pyruvate2-Keto-
isovalerate
Valine
Isobutyraldehyde
Isobutanol
2-keto-acid decarboxylase (KDC)
alcohol dehydrogenase (ADH)
ADDING NEW DNA
KDC gene comes from Lactococcus lactis
bacterium
ADH gene comes from Saccharomyces cerevisiae
bacterium
Cut new DNA and E. Coli plasmid with restriction
enzyme with selectible marker, creating new
recombinant DNA in a single bacterium when
treated with DNA ligase
BIOREACTOR CONDITIONS
A glucose-water solution would be continuously fed
into bioreactor inoculated with 1g of genetically
altered E. Coli
The bioreactor would be heated to maintain a
constant 37 degrees Celsius
The bioreactor will be aerated for maximum E. Coli
function
Valine-melts at 295°C
Isobutanol-107.89°C
Isobutyraldehyde-63°C
Ketoisovalerate-170.5°C
Pyruvate-165°C
Drum centrifugation will
remove any solids (“excess
glucose, cell metabolites,
biomass”)
Any valine will be removed
prior to distillation (solid)
The isobutanol can be
collected in the second fraction.
It has a significant boiling point
difference from other main
components
CENTRIFUGATION AND DISTILLATION
Boiling points of different
components:Procedure:
E. COLI ASSUMPTIONS
Characteristic Assumption
Unit Mass .3 picograms dry weight
Doubling Time 20 minutes
Consumption 20mmol glucose per g dry weight per hour
EXPECTED YIELD
Taking the 10,000kg of glucose as a basis for this
process:
Ideally, .41g of isobutanol would be formed per
gram of glucose
Assuming about 75% efficiency due to byproducts
and lost product during seperation, the 10,000kg of
glucose would yield about 1,015 gallons of
isobutanol. Mixed at 15% per gallon of gasoline, this
is 6,762 gallons of mixed fuel gasoline.
SCHEMATIC PART 1
Covered Cellulose
Fermenter
Covered Cellulose
Fermenter
Covered Cellulose
Fermenter
Wood Processin
g
Rotating
Drum
Boiler
Schematic Part 2
SCHEMATIC PART 2
Incoming Glucose Solution
Bioreactor
CentrifugeWast
e
Distillation
Isobutanol
Boom.
Water and
waste liquid
s
FEASIBILITY
Using only one cellulose fermenter would not make
a big difference
With multiple cellulose fermenters, the plan
becomes more and more reasonable. The E. Coli
functions faster than the protists, and could easily
handle an increase in feed glucose. With a significant
plant size, a plant could produce tens of thousands of
gallons of mixed biofuel per day.
THANKS FOR LISTENING
QUESTIONS?