''Schizochytrium'' is a genus of unicellular eukaryotes in the family Thraustochytriaceae, which are found in coastal

marine habitats Marine habitats are habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea (the term ''marine'' comes from the Latin ''mare'', meaning sea or ocean). A habitat is an ecological or environmental a ...

. They are assigned to the Stramenopiles (heterokonts), a group which also contains

kelp Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant - it is a heterokont, a completely unrelated group of organisms. Kelp grows in "underwat ...

and various microalgae.

Lifecycle

Several stages occur in its

lifecycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia *Biological life cycle, the sequence of life stages that an organism undergoes from birth to reproduction ending with the production of the offspring *Life-cycle hypothesis, ...

. The feeding form has a stiff, rounded body with cellular extensions used in feeding. Cells can transform into mobile flagellated cells with stiff tripartite hairs typical of the Stramenopiles. Cells can also grow and divide to form a cluster of cells which may become a

sorus A sorus (pl. sori) is a cluster of sporangia (structures producing and containing spores) in ferns and fungi. A coenosorus (plural coenosori) is a compound sorus composed of multiple, fused sori. Etymology This New Latin word is from Ancient G ...

that produces biflagellated zoospores.

Relation to humans

Certain species produce large amounts of docosahexaenoic acid (DHA) and are grown commercially for production of this oil for

animal feed Animal feed is food given to domestic animals, especially livestock, in the course of animal husbandry. There are two basic types: fodder and forage. Used alone, the word ''feed'' more often refers to fodder. Animal feed is an important input to ...

s, biomass,

biofuel Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. According to the United States Energy Information Administration (EIA ...

s and direct human consumption in supplements and additives. In 2016, juvenile

Nile tilapia The Nile tilapia (''Oreochromis niloticus'') is a species of tilapia, a cichlid fish native to the northern half of Africa and the Levante area, including Israel, and Lebanon. Numerous introduced populations exist outside its natural range. It i ...

were given a feed containing dried ''Schizochytrium'' in place of

fish oil Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), precursors of certain eicosanoids that are known to reduce inflammation in the body ...

. When compared to a control group raised on regular feed, they exhibited higher weight gain and better feed conversion, and their flesh was higher in omega-3 fatty acids. A 2020 study showed similar results and combined the feed with '' Nannochloropsis oculata'' for an entirely fish-free feed.

DHA synthesis in ''Schizochytrium''

DHA synthesis in ''Schizochytrium'' does not involve membrane-bound desaturases or fatty acid elongation enzymes such as those described for other eukaryotes. Instead it is thought that DHA synthesis in ''Schizochytrium'' occurs via a Polyketide synthase (PKS)-based pathway, although the primary structures of the Polyketide do not conform to any known class of PKS proteins. Homology between ''

Shewanella ''Shewanella'' is the sole genus included in the marine bacteria family Shewanellaceae. Some species within it were formerly classed as '' Alteromonas''. ''Shewanella'' consists of facultatively anaerobic Gram-negative rods, most of which are fo ...

'' and ''Schizochytrium'' PKS genes suggests that the genes involved in this pathway underwent lateral gene transfer.

References

Heterokont genera Bigyra {{Heterokont-stub