The U.S. Department of Energy’s Bioenergy Technologies Office (BETO) hosted a virtual workshop on algae crop protection on April 20–21, 2021. A major barrier to the scaling and intensification of algae cultivation is the partial or complete loss of productivity due to pests, just like in terrestrial plant biomass production.
Developing effective strategies to protect algal biomass production is essential to meeting BETO’s long-term goals of promoting cost-competitive algal-derived biofuels and bioproducts through increasing the annual average harvested yield of algal biomass.
The workshop convened 124 interdisciplinary experts from fields including algal research and production, agriculture, and aquaculture. Key features of the workshop included:
- Plenary presentations from BETO on event goals and an overview of the office’s mission and interest in the topic area
- Keynote presentations each day from outside the algal industry
- Panel presentations on four core technical content areas, including discussion on prepared question topics.
A detailed workshop report summarizing the proceedings is forthcoming. Presentations are also available online.
Day 1
Keynote: Barry Goldman, Pluton Biosciences
The day one keynote presentation was given by Barry Goldman of Pluton Biosciences. Dr. Goldman shared his experiences garnered during a career at Monsanto and Indigo Ag and how he is leveraging that knowledge at Pluton Biosciences with its “micromining” platform. Micromining identifies candidate microbes quickly by using a machine learning approach on screens of sub-populations.
Dr. Goldman offered a few key points on crop protection:
- The single gene/product solution approach to crop protection is difficult due to the cost and time to get a product to market.
- This traditional approach also suffers from the development of pest resistance, which has been observed in both insect and weed systems.
- A holistic systems approach is a more practical solution.
- Natural products and probiotics have a faster and cheaper product development cycle.
Session 1: The Current State of Algae Crop Protection
The first panel discussion and stakeholder input session focused on the current state of algae crop protection.
Panelists included:
- John McGowen, Arizona Center for Algae Technology and Innovation at Arizona State University
- Charles O’Kelly, Cyanotech
- Jason Quinn, Colorado State University.
Panel presentations highlighted the limited understanding and public data on algal pests, both in production systems but also in their natural ecosystem. The panelists emphasized that when you grow algae, you grow pests, and cultivation of algae outdoors requires active pest management approaches.
The facilitated stakeholder input session that followed focused on the themes that crop protection is a significant issue for algae growers and that no single pest is the most problematic. The panelists noted that choosing which host and pest system to work on is a significant barrier to conducting applied research and development. Workshop participants emphasized that the best way to determine the efficacy of a protection method is to measure harvested productivity. Mean time to failure was also highlighted as a valuable metric.
Many challenges in developing a successful crop protection strategy were discussed, most significantly:
- Replicating field conditions in the laboratory
- Improving understanding of the native microbiome of algal strains
- Addressing the high cost of developing solutions.
Through the discussion, it was clear that many participants agreed that better understanding in multiple research areas (including both basic and applied) is needed to advance the state of the art.
Session 2: Alternative Crop Protection Approaches
The second panel discussion and stakeholder input session focused on alternative crop protection approaches to chemicals and agricultural pesticides.
Panelists included:
- Rhona Stuart, Lawrence Livermore National Laboratory
- Kim Ogden, University of Arizona
- Jeremy Guest, University of Illinois Urbana-Champaign.
The panelists discussed crop protection strategies ranging from biological to mechanical controls. They also discussed how changes to aspects of a cultivation system may create selective pressures that could be managed for successful outcomes, and that manipulating the microbiome for crop protection purposes may be possible. The panelists noted that such approaches may have significant costs as well as regulatory implications for commercial algae cultivation.
The participant discussion focused on three key alternative approaches to pesticides:
- Altering the culture media
- Biological mechanisms such as designed consortia
- Mechanical/operational strategies.
Participants emphasized that to improve the design of biological approaches to crop protection, access to an open database of pests and their characteristics would be useful. As in other sessions, the discussion underscored the importance of understanding the microbiome in algal cultures.
Additionally, participants agreed that a better understanding for how pests recognize algae and how grazing occurs is needed to accelerate development of applied solutions. Regarding mechanical approaches to crop protection, participants noted that cheaper and more effective engineering solutions are necessary to advance the state of the art, including approaches such as improved filters for large scale cultivation to ensure pests can be removed.
Day 2
Keynote: Dr. Claire Gachon, Scottish Association for Marine Science, and the National Museum of Natural History in Paris
The second day of the workshop began with a keynote presentation covering research on pests of macroalgae (seaweeds) from Dr. Claire Gachon from the Scottish Association for Marine Science and the National Museum of Natural History in Paris.
Dr. Gachon highlighted that there is an unknown diversity of pests, that new pests are continually being discovered, and that reservoirs of pests exist globally. For one type of seaweed, when farming was intensified at different global locations there was a grace period of 5–10 years prior to culture collapse due to the establishment of a local pest population. This highlights the risk of farming new species without understanding the pests or developing mitigation strategies, as well as the need for a global biosecurity framework for seaweed aquaculture.
She presented work on possible solutions including:
- Using probiotics
- Breeding for disease resistance
- Mining for genetic markers of pest resilience to better understand how seaweeds defend themselves and applying that to crop protection.
Session 3: Pest Life Cycles and Infection Mechanisms
The third session of the workshop focused on pest models, specifically understanding pest life cycles and infection mechanisms.
Panelists included:
- Todd Lane, Sandia National Laboratories
- Shawn Starkenburg, Los Alamos National Laboratory
- Timothy James, University of Michigan.
The talks included observations by the panelists that strain collections contain few pest species but better information and ways to store and share pests could be beneficial to advancing the state of the art. They highlighted that genomics tools are becoming increasingly available and, when applied to pests, can greatly accelerate research. Pests can be divided based on broad or narrow host ranges, and techniques of study can be separated into applied and basic. These divisions may help direct future research efforts.
The group discussion focused on:
- The need for obtaining data from crash samples
- The creation of pest models based on the ecology and biology of pest/host interactions in complex systems
- The need to explore natural ecologies and share results in public collections and databases.
Session 4: Current and Future Pest Monitoring Practices
The final session of the workshop covered current and future pest monitoring practices.
Panelists included:
- Jeri Timlin, Sandia National Laboratories
- Natalie Cookson, Quantitative Biosciences, Inc.
- Ryan Simkovsky, University of California San Diego.
The presenters each emphasized the need for real-time in-situ monitoring for early detection of chemical and physiological changes to a culture, which would indicate a crash is imminent. In addition, they presented on:
- Spectroradiometric monitoring methods
- The capabilities of water quality monitory systems
- A mass spectrometry-based detection tool and plans for field deployment.
During the discussion session, the participants concluded that algae pond monitoring equipment should be robust, cheap (or pays for itself in productivity savings), and easy to use. In addition, the discussion emphasized that tools should have multiple applications (including outside of crop protection) in order to be useful and to aid affordability.
There was agreement that crop protection may not be able to rely on one detection tool and that pest identification tools and services would be useful and could provide isolation methods, assay development, host and pest phenotypic information, and recommended crop protection.
BETO would like to thank all the participants who contributed invaluable experience and insights to the workshop, making it a success.