Algae of commercial uses. It is a good medium on which to grow bacteria and fungi, as most microorganisms cannot digest agar. Alginic acid, or alginate, is extracted from brown algae. Its uses range from gelling agents in food, to medical dressings. Alginic acid also has been used in the field of biotechnology as a biocompatible medium for cell encapsulation and cell immobilization. Molecular cuisine is also a user of the substance for its gelling properties, by which it becomes a delivery vehicle for flavours. Between 100,000 and 170,000 wet tons of "Macrocystis" are harvested annually in New Mexico for alginate
Cavalier-Smith's system of classification four groups: In 1858, Richard Owen (1804–1892) proposed that the animal phylum Protozoa be elevated to the status of kingdom. In 1860, John Hogg (1800–1869) proposed that protozoa and protophyta be grouped together into a new kingdom which he called "Regnum Primigenum". According to Hogg, this new classification scheme prevented "the unnecessary trouble of contending about their supposed natures, and of uselessly trying to distinguish the Protozoa from the Protophyta". In 1866, Ernst Haeckel (1834–1919) proposed the name "Protista" for the Primigenum kingdom and included bacteria in this third kingdom of life. Fungi are more closely related to animals than