Awards issued prior to january 20, 2025, were funded under previous administrations and may not reflect the priorities and policies of the current administration.** farmed marine macroalgae present…

Awards issued prior to january 20, 2025, were funded under previous administrations and may not reflect the priorities and policies of the current administration.** farmed marine macroalgae present a carbon negative opportunity for feedstuff production, as theydo not require land conversion, fertilizers, or freshwater. Macroalgae are already used in smallquantities in some animal diets, but the complex polysaccharides are largely indigestible. Trials atocean ERA have shown that the microbes from herbivorous reef fish can be used as the inoculum fordeconstruction of macroalgae for aquaculture feeds. The project objective is to identify microbesthat are key to fermentation of tropical macroalgal species as partially digested macroalgae(PDMA) - a partial dietary replacement for aquaculture feeds. We will test a range of microbialisolates to optimize a reproducible fermentation process for deconstructing macroalgae intonutritionally beneficial feedstuffs. Reducing PDMA to a consistent, efficient process could providean economic engine for expanded seaweed farming, reduce aquaculture feed costs, and carbonfootprint. The focus of the proposedwork is microbial biomass conversion, for development of new aquafeeds from tropical macroalgae. We will ferment cultured macroalgae, with varying combinations of previously-isolated microbes, and then conduct feed trials with tilapia. Growth of tilapia will be used to evaluate effectiveness ofeach PDMA additive. With appropriate demonstration and scaling, PDMA could make a significantcontribution towards the decarbonization of aquaculture and global greenhouse gas reductiontargets. By establishing a controlled, repeatable process, we will be able to license these processesto agribusiness.