Pichia pastoris has been reassigned to the genus Komagataella after phylogenetic analysis of gene sequences, and split into three species, K. pastoris, K. phaffii, and K. pseudopastoris. These species are facultative methylotrophic yeasts: they are able to use single carbon compounds (e.g. methanol or methane) or multi-carbon compounds with no carbon-carbon bonds (e.g. dimethyl ether or dimethylamine) as a food source. After years of study, P. pastoris has been widely used in Biochemical research and Biotech industries as an expression system for protein production because of its high growth rate, low cost of culture, and ablility to produce proteins with disulfide bonds and glycosylation.