This document summarizes an experiment on the effect of light frequency on the growth of Chlamydomonas reinhardtii microalgae. The experiment tested 6 different light frequencies ranging from 0-100 Hz over time periods of 6 and 18 hours. The results showed that microalgae growth responded to changes in light frequency, with higher growth rates at some frequencies compared to others or the control. Future work is proposed to further analyze the relationship between light frequency and algal growth, and whether this could be related to Kelly's betting model. The growth response to light frequency could potentially be used to optimize industrial photobioreactor lighting and increase microalgae production.

1. OSAMA ASKOURA
Interpreting Chlamydomonas
reinhardtii Growth using Kelly’s
betting model

2. Slide
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ROADMAP
Introduction
Related Work
Experimental Methods and Materials
Lab Experimentation
Results and Analysis
Conclusion
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2 Fig 1: Bamboo (top), Algae (bottom)
SOURCE: Google Images
Algae could be used as a biofuel
Algae is one of fastest growing crops
on Earth.
Puts it in front with Bamboo plant.
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Micro algae can be used in
biofuel production
Fig 2: Algae oil separation
SOURCE: Google Images
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6. Effect of light frequency on the
growth of Chlamydomonas
reinhardtii micro-algae

7. Why Chlydomonas reinhardtii?

8. Micro-algae has fast growing rates.
Chlamydomonas reinhardtii Can double in 6 hours.
Makes it perfect for lab experimentation.

9. HYPOTHESIS
HYP#1:
Micro-algae responds to incident light frequency
HYP#2:
Micro-algae does not respond to incident light frequency
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RELATED WORK
Kelly [2] related the growth of capital to the rate of information
Vejrazka, 2011 [5] investigated the effect of fluctuations on
microalgae. Their results showed decreased growth rates with higher
frequencies.
Vejrazka also showed that algal growth rates are higher under light-
limiting conditions
Cuaresmaa, 2011 [6] results show that horizontal bioreactors yield
higher culture biomass
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EXPERIMENT
Total: 6 conditions
1 control
5 different frequencies
6 hour experiments
18 hour experiments
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EXPERIMENTAL SETUP
Photon Flux Density (PFD) intensity 100-110 μmol photon /m2s
Incident light 470nm blue light
Duration
6 hours
18 hours
Light path 20 mm
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Every
1-2 weeks
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PROCEDURE
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RESULTS AND ANALYSIS
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FREQUENCY (Hz)
OPTICAL DENSITY (UNITLESS)
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29. Frequency
(Hz)
Growth
Average of
3 samples
0 226
10 221
20 230.3
40 242
80 258
100 225
226
221
230.3
242
258
225
215
220
225
230
235
240
245
250
255
260
0 20 40 60 80 100 120
GROWTH/ABSORBANCE
FREQUENCY (Hz)
Growth of Algae under different light frequencies of
470 nm blue light ( 6 HOURS )
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30. Frequency
(Hz)
Growth
Average of
3 samples
0 231
10 266.5
20 256
40 257
80 272.5
100 264
231
266.5
256 257
272.5
264
225
230
235
240
245
250
255
260
265
270
275
0 20 40 60 80 100 120
GROWTH/ABSORBANCE
FREQUENCY (Hz)
Growth of Algae under different light frequencies of
470 nm blue light ( 18 HOURS )
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31. Frequency
(Hz)
Growth
Average of
3 samples
0 231
10 266.5
20 256
40 257
80 272.5
100 264
225
230
235
240
245
250
255
260
265
270
275
0 20 40 60 80 100 120
GROWTH/ABSORBANCE
FREQUENCY (Hz)
Growth of Algae under different light frequencies of
470 nm blue light ( 18 HOURS )
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DISCUSSION & FUTURE WORK
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Relationship is not linear
Could the algal response be related to Kelly’s betting?
Our results show that we can modify existing industrial
photobioreactor light patterns to increase growth at no cost.
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SUMMARY
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In our project we studied the effect of fluctuating light regimes on
the growth of Chlamydomonas reinhardtii micro-algae.
The growth of the algae was investigated against the light frequency
Our data has shown a clear and direct response by the algae to the
frequency
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Thanks to Wheeler’s Microfluidics Laboratory at
University of Toronto for provision of laboratory
space, materials and equipment.
Acknowledgments
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[1] C.E. Shannon A Mathematical Theory of Communication, B.S.T.J., Vol. 27, 379-656 (1948).
[2] Kelly, J.L A new interpretation of information rate, IRE Transactions, Vol. 2, 185-189 (1956).
[3] Hans C. P. Matthijs, Hans Balke, Udo M. van Hes, Bernd M. A. Kroon, Luuc R. Mur, Roger A. Binot Application of light-emitting
diodes in bioreactors: Flashing light effects and energy economy in algal culture (Chlorella pyrenoidosa), Biotechnology and
Bioengineering, Vol. 50, 98-107 (1996).
[4] Carl T. Bergstrom, Michael Lachiriaiiii Shannon Information and Biological Fitness, IEEE, Vol. 2, 185-189 (2004).
[5] Carsten Vejrazka, Marcel Janssen, Mathieu Streeand, Rene H. Wijels Photosynthetic Efficiency of Chlamydomonas reinhardtii
in Flashing Light, Wiley, 489, 2905-
2913 (2011).
[6] Mara Cuaresmaa,b, Marcel Janssena, Carlos Vlchezb, Ren H. Wijels Horizontal or vertical photobioreactors? How to improve
microalgae photosynthetic efficiency , Elsevier,
Vol. 2, 185-189 (2011).
References
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