Photos courtesy of R.O. Megard Photos courtesy R.O. Megard
Ecological approaches to disease management in open
pond cultivation systemsVal H. Smith, University of Kansas, Lawrence, KS
Rob McBride, Sapphire Energy, Inc.Tim Crews, Land Institute, Salina, KS
Mass cultivation of microalgae for biofuels production
Nutrients and light
Carbon dioxide(CO2)
Phosphate (PO4
-3)Light Nitrate
(NO3-)
Modified from www.fish.washington.edu/classes/fish210/data/Lectures/Lecture%2013.ppt
Silicate(SiO2)
This is the vision:
kmle.co.kr
http://brae.calpoly.edu/CEAE/biofuels.html
And this is what the algal crops will be cultivated in:
Closed photobioreactors
Open pond systems
http://www.sapphireenergy.com/locations/green-crude-farm.html
But the world is full of potentially devastating disease
agents…
calanoid copepod NOAA.jpg‑ ‑
calanoid copepod NOAA.jpg‑ ‑
Alan Wilson
Chytrids and other pathogenic fungi
http://www.ccalmr.ogi.edu/files/images/aformosa.jpg; http://genome.jgi-psf.org/ChlNC64A_1/ChlorellaNC64A.jpg; http://aem.asm.org/content/71/2/629/F5.large.jpg;
(diatom)
Phycoviruses
Chlorella
Cyanophages
Cyanobacteria
…that can cause major crashes…
Sapphire Energy
…and the pathogen load can increase in abundance and diversity over time
Sapphire EnergySapphire Energy
The control of infectious disease is a critically important area of research
The use of multi-species polycultures has important implications for crop stability
Photos courtesy R.O. Megard
Increasing algal diversity decreases disease prevalence
Diversity or abundance of diluting species
Dis
ease
pre
vale
nce
(% o
f tot
al a
lgal
cel
ls)
Modified from Johnson and Thieltges 2010. J. Exper. Biol. 213: 961-970
Dilution effects of algal diversity on disease
Specialist pathogen
Highly susceptible single-species monoculture
Pathogen dilution by diverse, multi-species polyculture
http://www.microscopy-uk.org.uk
Specialist pathogen
What about non-chemical control of algal pathogens?
Biological control has been used since 324 AD!
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB0QFjAA&url=https%3A%2F%2Finsects.tamu.edu%2Fstudents%2Fundergrad%2Fento401%2FLecture06-BioControlPrinciples.ppt&ei=xQXXU4uVFJKNyASCoILYBQ&usg=AFQjCNFwueoEDg_BurbMvekfuUXwB26wiw&sig2=sAWxZBIid8Y9lO8j6lmrWg&bvm=bv.71778758,d.aWw&cad=rja
Strong effects of microconsumers on chytrid infections of amphibians
Woodhams et al. 2011. Frontiers in Zoology 8:8; Schmeller et al. 2014. Curr. Biol. 24: 176–180; http://dx.doi.org/10.1016/j.cub.2013.11.032
Potential use of microconsumers to control chytrid infections of microalgaeChytrid
zoospores
Abundant microconsumers Few or no microconsumers
Prev
alen
ce o
f in
fect
ed a
lgal
cel
lslo
whi
gh
Rotifers Ciliates www.aslo.org; wikipedia
Where do we go from here?
• Explore the effects of algal diversity on disease prevalence and disease transmission
• Explore new, non-chemical methods to control the growth of algal pathogens –Design optimal food web structure to
minimize disease prevalence and disease transmission
Acknowledgements• Bob Honea, Director, KU TRI• KU Feedstock to Tailpipe team• U.S. DOE and NSF EPSCoR