This project continues the development of soybean germplasm with oil quality traits optimized for high value soy-based aquaculture feeds. The project is consistent with the Nebraska Soybean Board (NSB) 2022 priority of supporting research projects for the adjustment of soybean seed composition to enhance marketability of Nebraska soybeans. The research builds on past NSB funding that led to the development of soybeans containing the fish oil fatty acid EPA, astaxanthin for fish flesh pigmentation, and enhanced vitamin E antioxidants for improved fish shelf-life. The project will continue the development of germplasm producing these two high-value aquaculture feed components. This research will also maintain our soybean aquaculture germplasm development pipeline to generate seed oil with DHA, along with EPA, to more closely mimic fish oil-type fatty acids. The project will focus on strategies that enable the production of these enhanced oil traits without compromising seed performance and protein levels. Approaches will also be explored to increase oil content of EPA/DHA-enriched seeds. This trait may have added benefits for biodiesel applications. Overall, this research is expected to generate germplasm that produce EPA/DHA-containing oils alone or stacked with astaxanthin and vitamin E antioxidants to supply multiple emerging market streams for soybean-based aquaculture feed.

The proposed research addresses the need for soybean germplasm with high-value oil quality traits for aquaculture feed. Our research will generate soybean-based aquaculture feedstocks enriched in EPA and DHA omega-3 fish oil fatty acids, astaxanthin for fish flesh pigmentation, and enhanced vitamin E antioxidants to enhance fish shelf-life and reduce off-flavors and odors. The proposed research will continue our development of soybean aquaculture germplasm by:
1. Maximizing production levels of EPA and DHA in oil of engineered soybean seeds.
2. Enhancing oil content of seeds engineered for EPA and DHA production without compromising seed protein content and agronomic performance.
3. Advancing existing germplasm with fish oil functionality, astaxanthin pigments, and enhanced vitamin E antioxidants through our soybean aquaculture development pipeline for fish feed testing and bioprocessing research.

Timeline and Milestones for Research:
Aims 1. FY22: Complete gene expression constructs, initiate transformation. FY23: Evaluate and advance greenhouse-grown top-performing lines. Milestone: Lines with 210% EPA and 24% DHA identified. FY24: Top lines with good agronomic performance field-tested. Aim 2. FY22: Complete gene expression constructs, initiate transformation. FY23: Evaluate and advance greenhouse-grown top-performing lines. Milestone: Lines with 210% EPA, 24% DHA with 218% oil, no protein penalty. FY24: Top lines with good agronomic performance field-tested. Aim 3. FY22: Evaluate and advance stacked lines from greenhouse to field FY23: Milestone: Stacked lines 210% EPA, 24% DHA, 2100 µg/g astaxanthin, 2800 µg/g vitamin E. FY22-24: Field evaluation and bulking of seeds with stacked oil traits. FY23-24: Seek feed trial and bio-processing collaborations.

Economic Benefit for Nebraska Soybean Producers:
The project will deliver soybean germplasm with oil composition tailored for multiple high-value aquaculture feed streams with no or minimal impact on seed protein levels. Aquaculture is one of the fastest growing food markets. Demand for aquaculture feed is expected to increase annually by >7% to $71.6 billion USD by 2025. Astaxanthin is currently the most expensive aquaculture feed components at ~$2,500/kg.

Findings and potential intellectual property resulting from the proposed research will be disseminated to the Nebraska Soybean Board. Key findings generated from these studies will be made available to the public through presentations at national and international meetings and by publication in refereed scientific journals, following filing of patent applications, as needed, for intellectual property protection.

Updated May 26, 2023:

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The project has addressed the Nebraska Soybean Board focus area of germplasm improvement for composition and yield. The project has generated germplasm that produces seed oils with the key, high value traits: fish oil EPA, astaxanthin pigment for consumer-desired fish flesh color, and high vitamin E antioxidants to stabilize EPA from production of off-flavors. Nearly 50% of fish that is consumed globally is farm-raised, and this production system is anticipated to expand as
world population grows, ocean stocks of fish dwindle, and consumers place more emphasis on fish for healthy diets. Soybean is and will increasingly be a major sustainable source of aquaculture protein and oil feedstocks. Our research will increase the bushel price of soybeans and deliver high value oil traits that will increase the market share of Nebraska and US soybean for the aquaculture feed market.

This project aims to develop soybean germplasm with oil quality traits optimized for high value soy-based aquaculture feeds, one of the most significant new markets for Nebraska soybean producers. Continued expansion of US and global aquaculture production requires development of sustainable feedstocks of land-based protein meal, omega-3 fish oils, and flesh pigments, which can be met in large part by soybean-derived feed. This project will improve oil quality traits to increase the amount of soybeans used in aquaculture feed. This is expected to translate into increased demand and expanded markets for Nebraska soybeans. The project builds on successes of the investigators from prior Nebraska Soybean Board funding that has generated soybean germplasm approaching commercially-viable levels of omega-3 fish oil-type fatty acids and astaxanthin pigment coupled with high vitamin E antioxidants for improved shelf life. This enhanced germplasm will be developed to supply multiple market streams for soybean-based aquaculture feed to increase profitability for Nebraska soybean farmers.