25/03/2025
This blog is the fourth part of a series on innovations in the alternative protein sector. To read the other parts of the series, please see here.
90% of the world’s oceans are either overfished or fished to the maximum sustainable level; however, as the global population is rising along with standards of living and awareness of the health benefits of seafood, the demand for fish is estimated to be twice as high as the supply of sustainably caught fish.1
Overfishing can result in loss of biodiversity and can reduce the ocean’s ability to capture carbon dioxide, which is needed to mitigate climate change.2 There are, moreover, various risks associated with the consumption of wild-caught seafood, among them contamination by pollutants. Pollutants frequently undergo biomagnification up food chains, as large carnivorous species such as tuna consume numerous smaller fish and absorb pollutants from their food into their tissues. High concentrations of heavy metals such as mercury, persistent organic pollutants, insecticides and microplastics may therefore be found in wild-caught seafood. Another risk to consumers of wild-caught seafood relates to seafood fraud: many fish sold by fishmongers and markets worldwide are actually misidentified and mislabelled.3, 4 Industrial aquaculture, or fish farming, presents its own problems — diseases among the fish, animal welfare issues such as overcrowding, and pollution of the surrounding aquatic environment through the use of pesticides to control parasites are just a few of these.
Cultivated seafood, or cellular aquaculture, presents an attractive no-slaughter alternative to wild-caught seafood and industrial aquaculture. To produce cultivated seafood, cells from fish, cephalopod, mollusc or crustacean species may be taken from these animals and grown in a bioreactor. Cultivated seafood may be created through tissue engineering in a process involving biopsy of cells from an animal, isolating the desired cells, expanding the cells (i.e., allowing them to multiply), differentiating the cells into appropriate cell types, harvesting the cells and formulating a product.
Turning now to some technical aspects, muscles of fish and cephalopods are different from each other and different from than those of land vertebrates. Cooked fish are frequently described as “flaky.” This is because fish muscles are organised into sheets called myomeres. These are structures in which the fibres are perpendicular to the long axis of the muscle. Myomeres are separated from each other by layers of fat and connective tissue. In cephalopods, muscles have fibre bundles running in three orthogonal directions due to the animals’ reliance on jet propulsion to swim. Crustaceans and bivalve molluscs, on the other hand, have muscles like land vertebrates in which the muscle fibres run in a single direction. Although certain species of fish (such as zebrafish) have been extensively studied in culture, marine invertebrate cells have been less extensively cultivated and so less is known.5
A summary of the technical problems and brief descriptions of selected patent filings by some innovative companies within the industry follows.
Similarly to cultivated meat, creating unstructured products is technically a bit easier and early cultivated seafood products have tended towards being less structured. One example of a less structured product is surimi, minced white fish that may be used to make imitation crab sticks. Cultivation of surimi is the aim of the start-up Fisheroo in Singapore.6
Similarly to cultivated meat, considerable problems involved in scale-up of the culturing of cells must be solved before cultivated seafood can be brought to market affordably.
When aiming to produce large volumes of cells from seafood species, as with cells from land vertebrates, relevant considerations include cell numbers, differentiation, growth rates, and whether the cells are/can be selected or engineered to thrive in particular environments (e.g. low or no serum, scaffold-free) or immortalised (and what these things means from a regulatory and consumer acceptance perspective).
Relevant patent families relating to cell selection include Wild type’s WO2018/227016, an early patent family to ex vivo meat production with claims to culturing fish and cephalopod cells; Shiok Meats’ (now merged with UMAMI Bioworks) WO2020/149791 to isolation and cultivation of muscle and fat cells from crustaceans; CellMEAT’s KR102691861 to crustacean cell lines with reduced tropomyosin expression; and CellQua’s KR20240125313 to methods for isolation and culture of primary cells from aquatic animal tissues.
Efforts are being made within the industry to reduce the expense of culture media while maintaining strict sterility standards, and to replace animal serum with other materials. The expense of culture media, supplements and growth factors is one of the major economic barriers to affordable scale up of cultivation processes.
Relevant patent families relating to culture media include Sea2Cell’s WO2024/134658, in which, in addition to the target cells, the culture media is also seeded with supporting cells of an aquatic species that may secrete a recombinant growth factor; CellMEAT’s WO2024/039216 to a method of culturing cells in a serum-free medium containing a yeast extract; and CellQua’s KR20240103616 to a serum-free medium composition containing rice and/or egg white extract.
Most cells from cultivated seafood species are “anchorage dependent” meaning that they cannot be grown directly in suspension and require a substrate on which to grow.7 In vivo, the proteins and carbohydrates of the extracellular matrix (ECM) provide structural support to the cells and facilitate intracellular communication by cell signalling, which may drive growth, division and differentiation. Moreover, as cells in suspension are sensitive to shear forces within bioreactors, they require structural support to mitigate these effects.
The composition of the scaffolding and properties such as porosity, stiffness and biodegradability are all relevant. However, the use of scaffolding can sometimes be avoided entirely with certain cells and under certain conditions. Cells have some ability to create their own ECM and to self-assemble as aggregates, and sometimes even into small organised tissues resembling organs known as organoids.7
German start-up Bluu Seafoods, which specialises in Atlantic salmon and rainbow trout, cultivates cells as aggregates without the use of scaffolding. It produces relatively unstructured hybrid products such as fish fingers by combining the cultured fish cells with plant proteins. It has submitted applications for regulatory approval of its products in Singapore and the US.8
Relevant patent families relating to scaffolding include Wild type’s WO2020/123876 to edible compositions including polymeric fibrous scaffolding; Sea2Cell’s WO2024/241315 compositions comprising edible hydrogel microcarriers comprising cells; and CellMEAT’s WO2023/106724 to scaffolding based on microbial derived biocellulose.
One opportunity for producers of cultivated meat and seafood is to use their platforms to improve the nutritional profile of their foods, relative to traditionally caught or farmed foods. There are numerous possibilities at different stages of processing. One example of this is BlueNalu’s WO2022/221261, which describes culturing cells under certain conditions to modify their fatty acid content relative to wild caught species.
As with cultivated meat, whole cuts of fish are challenging to make. Two approaches to this problem, also discussed in the previous blog, include a bottom-up approach and a top-down approach. A bottom-up approach constructs a product using modular units of scaffolds and cells, while a top-down approach relies upon a previously assembled or self-assembled structure to construct a product.
A bottom-up approach is being taken by UMAMI Bioworks in collaboration with Steakholder Foods to produce a 3D-bioprinted hybrid cultivated grouper. Unlike products only containing animal cells which require time to incubate and mature after the printing process, the hybrid grouper is ready to cook upon printing.9
An interesting example of a top-down approach is being taken by Forsea Foods to produce cultivated unagi, or Japanese freshwater eel. The freshwater eel is a critically endangered species and difficult to breed in captivity, yet demand for its meat is high, and it is considered a delicacy.10,11 Forsea is cultivating eel meat using organoid technology, which is scaffold free and self-assembling. It has achieved remarkable cell densities in culture.12 Families WO2023/187771 and WO2022/201147 relate to the use of cells to produce cultivated meat through self-assembly of organoids.
Similarly to cultivated meats, the production costs involved in the cultivation of seafood must be brought down to provide consumers with affordable options; therefore many companies are currently formulating hybrid products that contain both cultivated animal cells and other components, which are frequently plant based.13 Examples of such products already discussed above include Bluu Seafood’s fish fingers and UMAMI Bioworks’ grouper. CellMEAT has filed family KR102722622 to cultured cell-based caviar, which is a hybrid product including cultured cells along with alginate and seaweed powder.
Aside from the above technical concerns, there are regulatory implications for cultivated seafood as novel foods, as well as the question of whether cultivated seafood will ultimately gain acceptance by consumers. Cultivated seafood has not yet garnered regulatory approval anywhere in the world, although the first applications for approval are being made.
As evidenced by the numerous patent families discussed above, companies are making technological advances, yet the cultivated seafood industry, like the cultivated meat industry, is still nascent.
This article is for general information only. Its content is not a statement of the law on any subject and does not constitute advice. Please contact Reddie & Grose LLP for advice before taking any action in reliance on it.
References
3 The characterization of seafood mislabeling: A global meta-analysis – ScienceDirect
5 Cultivated meat end products | Deep dive | GFI
6 Cultivated, fermentation-derived, or hybrid surimi – The Good Food Institute
7 Cultivated meat scaffolding | Deep dive | GFI
9 Umami Bioworks & Steakholder Foods to Scale Up 3D-Printed Lab-Grown Fish
10 Lab-Grown Eel Producer Achieves ‘Record-Breaking’ Development
11 Adored and endangered: the complex world of the Japanese eel
12 Forsea Foods creates eel meat using patented organoid technology
