The history of Chlorella
A green algae more than 2 billion years old
Chlorella is a green algae that appeared on Earth more than 2 billion years ago. Consisting of a single spherical cell, it owes its color to chlorophyll (the photosynthesis pigment), which it contains in exceptional quantities.
Discovered in 1890 by Dutch microbiologist Martinus Willem Beijerinck, Chlorella has been divided into three varieties since 2004  : Chlorella vulgaris, Chlorella lobophora, and Chlorella sorokiniana. Chlorella vulgaris is currently the most widely cultivated, as it is the one best suited to algae farming.
Historically, Chlorella was first produced and consumed in Asia, primarily in Japan – although the island of Formosa (present-day Taiwan) soon became the world’s largest producer.
Much research was conducted into Chlorella starting in 1950, when it was viewed as a potentially useful way to combat a possible global food shortage  due to population increase. It was not chosen as a viable solution due to the difficulty of digesting it in its natural state – its cell walls are made of cellulose that needs to be broken down.
Chlorella’s healing abilities have been proven. In Japan, it is even considered a food in the national health interest – a research institute focused on Chlorella was founded there in 1957.
 Lothar Krienitz, Eberhard H. Hegewald, Dominik Hepperle, Volker A. R. Huss, Thomas Rohr, and Matthias Wolf (2004) Phylogenetic relationship of Chlorella and Parachlorella gen. nov. (Chlorophyta, Trebouxiophyceae). Phycologia: September 2004, Vol. 43, No. 5, pp. 529-542.
 Ortiz Montoya EY. & al. : Production of Chlorella vulgaris as a source of essential fatty acids in a tubular photobioreactor continuously fed with air enriched with CO2 at different concentrations. Biotechnol Prog. 2014 Jul-Aug;30(4):916-22. doi: 10.1002/btpr.1885.
Chlorella has been declared by the Japanese government as a food in the national health interest.