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