Post on 24-Feb-2016
description
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