Enzymatic Hydrolysis of cellulose for production of fuel ethanol by SSF
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Transcript of Enzymatic Hydrolysis of cellulose for production of fuel ethanol by SSF
Enzymatic Hydrolysis of cellulose for production of fuel ethanol by SSF
Presented by Alaaedine Talab
What is SSF?
The reaction
The reaction continuedβ(1→ 4)
Purpose of SSF
• Minimize Hydrolysis byproducts• Economically favorable• Minimize inhibitory factors• Eliminate transfer time
SSF Kinetics
Cellulose cellobiose glucoser1 r2
Experimental Procedure• Effects of specific components of SSF system
• Assays done in Y/P medium (10g/L yeast extract, 20g/L peptone), PH = 5.0 at 38C
• Trichoderma Reesei• Initial rates determined after enzyme
deactivation(20 minutes boiling water, denatur) 15s intervals 1 minute duration
How do we measure enzyme activity as an uncoupled system?
3g/L
We can simplify the volumetric rate constants
=
constant
Effect of cellobiose on cellulase activity
Avg.
Effect of cellobiose on B-glucosidase
K2B?
Effect of cellobiose on B-glucosidase
Maximal rate
Glucose concentration and enzyme activity
Ethanol concentration and Enzyme activity
K2E = NEGLIGIBLE
Summary
Putting it all together
Putting it all together continued
• Almost perfect fit but not yet
• Why?
First order rate loss added to model
• Fail
(Conclusion)So what?
• R^2> 0.98• Developed a quantitative mathematical model
that can predict SSF progress• This applied to enzymes from T. risea however
model can be used to calculate other microbe kinetics
• Can be used for process, design, optimization and scale-up (industrial purpose) to enhance ethanol productivity
Critique
• Take into account Cellulase inactivity• Understand mechanisms of inhibition (i.e.
feedback inhibition)• Use larger concentrations of substrate (max =
120g/L)
References
• http://www.ncbi.nlm.nih.gov/pubmed/18609632
• http://bio-process.com/wp-content/uploads/2009/12/Cellulosic-SSF.pdf