Mixotrophic nutrition is exhibited by the kingdom Protista.
What are mixotrophs?
Mixotrophs are organisms that use a mix of different sources of energy and carbon rather than a single trophic mode. Euglena is an autotroph as well as a heterotroph and is called a mixotroph.
Protista
Protists are simple eukaryotic organisms that are neither plants nor animals or fungi. Protists are unicellular in nature but can also be found as a colony of cells. Most protists live in water, damp terrestrial environments, or even as parasites.
Not all protists are mixotrophs. A few protists are strict heterotrophs. While a few are both autotrophs and heterotrophs. The mixotrophic protists are called acetate flagellates.