MASSACHUSETTS INSTITUTE OF Technology
Department of Biology
TW 2014 Biofuel
Converting Cellulosic Biomass to Ethanol
Activity from CB2E from Great Lakes Bioenergy Research Center, Golden, Colorado
https://www.glbrc.org/education/classroom-materials/cb2e-converting-cellulosic-biomassethanol
Summary |
One abundant, cheap and under-utilized source of raw material for the production of biofuel
(bioethanol) are cellulose and lignin, which are the major components of plant cell walls and are
very hard to breakdown. In this lab you will investigate the challenge of converting various
cellulosic biomasses first into glucose, and then into ethanol. In this experiments we will use a
defined 3-step process of (1) pretreatment, (2) enzymatic treatment, and (3) yeast fermentation of
the sample to produce ethanol, and we will look at the efficiency and challenges of the process.
We will start with mechanical force, chemicals and heat to separate the lignin and cellulose from
raw plant material, and then use various enzymes isolated from living organisms to
biochemically breakdown cellulose into glucose. Finally we will add yeast to ferment that
product and measure the ethanol produced to determine effectiveness of the overall process.
In this inquiry-based activity, students will see which team can produce the most ethanol per
gram of dry cellulosic biomass. Each team will pick a cellulosic biomass sample, break it down,
convert it into glucose, and then into ethanol through the processes described below. Students
will track the conversion process by measuring glucose and ethanol levels at key stages. This
data collection by the various teams will help determine which biomass source (feedstock) and
pretreatment methods (mechanical, heat, pH) and enzymes are most effective at producing sugars
and ethanol and test their predictions. Students will use this information to develop explanations
for why some samples produced more sugar and ethanol than others.
Background Information
Teacher manual, student manual and other support materials including PowerPoint, graphic
organizers, and worksheets for Experiment CB2E (Converting Biomass to Ethanol) from Great
Lakes Bioenergy Research Center, Golden, Colorado are available at
https://www.glbrc.org/education/classroom-materials/cb2e-converting-cellulosic-biomassethanol
Objectives (from CB2E)
 Test predictions about how variables (biomass type and grinding method) affect
conversion into sugars and ethanol
 Trace the transformation of cellulose into glucose and then ethanol
 Assess the action of cellulase enzymes on cellulose
 Measure the conversion of sugars to ethanol
 Use sugar and ethanol readings to evaluate initial predictions and draw conclusions about
the effects of treatment variables.
PLACE YOUR NAME HERE 2012
MASSACHUSETTS INSTITUTE OF Technology
Department of Biology
TW 2014 Biofuel
Materials in the Kit designed for class of 24, working in groups of 3 and available upon
request to Mandada@mit.edu) will include:
 6 Vernier LabQuest LabQ2 @ 329.00
 8 Vernier Ethanol Sensors ETH_BTA @ #109.00
 1 roll Plumbers tape
 4 TRUEbalance Blood Glucose Meters
 (1 other Blood Glucose Meter)
 Blood Glucose Strips for TRUEbalance or other meter (specific to meter) 100
strips/class
 Parafilm
 Disposable pipettes (30 for 1 class)
 Celluclast (Cellulase) in aqueous solution
o For cellulase (C2730) the optimal pH range is 4.5 - 6.0, and the optimal
temperature range is 50 - 60°C.
o Produced by submerged fermentation of a selected strain of the fungus
Trichoderma reesei and catalyzes the breakdown of cellulose into glucose,
cellobiose, and higher glucose polymers.
 50mL falcon tubes, 2 packages of 20
 Printed copy of student manual
 Printed copy of teacher manual
Materials provided by the school
 Weigh boats
 Electronic Balance
 Grinder for biomass samples
 Scissors, shears, saw for cutting biomass
 25 or 50 ml graduates
 600 ml beakers
 Hot plates
 Thermometer
 Blender to cut up Biomass Samples, such as Ninja Kitchen System Pulse (BL201)
Grinder or similar product
 Other enzymes if desired (pectinase, amylase)
Procedure
Student and Teacher Manuals for CB2E available at
https://www.glbrc.org/education/classroom-materials/cb2e-converting-cellulosic-biomassethanol and single copies are included in the kit.
PLACE YOUR NAME HERE 2012
MASSACHUSETTS INSTITUTE OF Technology
Department of Biology
TW 2014 Biofuel
Additional Resources at
https://www.glbrc.org/education/classroom-materials/cb2e-converting-cellulosic-biomassethanol
 Concept Map 8.5x14.pdf
 Concept Map.pdf
 Developing a Scientific Argument.pdf
 Introduction Discussion Questions.pdf
 Introduction Questions Answer Key.pdf
 Presentation slides
 Slide notes.pdf
 Why is it so difficult to make cellulosic ethanol? pdf
PLACE YOUR NAME HERE 2012
MASSACHUSETTS INSTITUTE OF Technology
Department of Biology
TW 2014 Biofuel
PLACE YOUR NAME HERE 2012
MASSACHUSETTS INSTITUTE OF Technology
Department of Biology
TW 2014 Biofuel
PLACE YOUR NAME HERE 2012