Enrichment processes for the production of high-protein feed from the green seaweed Ulva ohnoi

The Future of Aquatic Protein: Implications for Protein Sources in Aquaculture Diets

“…105 Importantly, the quality of the concentrated protein in that study was comparable with that of soybean meal and white fish meal, suggesting that it would be a suitable protein replacement option, with the caveat that it still must be tested in vivo. 105 Although this process is currently in its infancy, the development of macroalgae as a source of protein will provide a net increase to the supply of protein for the world. Macroalgae cultivated through bioremediation represents an environmentally friendly alternative to many traditional sources of protein and will help to alleviate some of the competition for protein resources between aquaculture and terrestrial livestock production.…”

“…The potential scale of this resource is impressive, with a demonstrated biomass production rate of 45-70 tons of dry weight hectare À1 per year and an average crude protein content of $22%. 103,105 The proportion of crude protein in macroalgae, particularly when harvested from the wild, is highly variable, ranging from <1% to 48% of the biomass dry weight, 99,[106][107][108][109] and depends on both species and environmental conditions. It should be noted that many of the crude protein values reported in the literature are overestimated, 110 and the true crude protein content, representing a more realistic range, is 10%-30% when grown under non-limiting nutrient conditions.…”

“…This can be achieved either through the direct extraction and isolation of protein or by removing non-protein components, such as ash and soluble carbohydrates, thus increasing the relative proportion of protein in the residual macroalgal biomass. 105,[143][144][145][146] However, these processes are still being developed and while not yet commercialized, 145 they have been successfully applied to Ulva ohnoi, a commercially grown bioremediation species, to increase its protein content from 22% to 45% on a dry-weight basis. 105 Importantly, the quality of the concentrated protein in that study was comparable with that of soybean meal and white fish meal, suggesting that it would be a suitable protein replacement option, with the caveat that it still must be tested in vivo.…”

“…105,[143][144][145][146] However, these processes are still being developed and while not yet commercialized, 145 they have been successfully applied to Ulva ohnoi, a commercially grown bioremediation species, to increase its protein content from 22% to 45% on a dry-weight basis. 105 Importantly, the quality of the concentrated protein in that study was comparable with that of soybean meal and white fish meal, suggesting that it would be a suitable protein replacement option, with the caveat that it still must be tested in vivo. 105 Although this process is currently in its infancy, the development of macroalgae as a source of protein will provide a net increase to the supply of protein for the world.…”

Effects of preservation on protein extraction in four seaweed species

“…Other studies on Ulva species reported an even higher protein content values, up to 26.2 g protein (100 g) −1 DW (Shuuluka et al 2013;Bikker et al 2016;Harrysson et al 2018;Magnusson et al 2019). Also with the higher protein values un the Ulva biomass, Bikker et al (2016) and Magnusson et al (2019), with slightly different extraction methods, found a comparable increase in protein content of the remaining pellet. Bikker et al (2016) increased the protein content of U. lactuca by dissolving the biomass in water of 150°C followed by enzymatic hydrolysis.…”