The past five years have seen an exponential growth in the use of the methylotrophic yeast Pichia paslOris as a heterologous protein expression
system. The existence of yeasts that grow on methanol as a sole source of
carbon and energy was unknown just 30 years ago, in contrast to baker's
yeast, Saccharomyces cerevisiae, which has been exploited by humans for
several millennia. However, as a result of intensive efforts during the 1970s
by Phillips Petroleum bioengineers to develop P. pastoris for the production
of single-cell protein and during the 1980s by molecular biologists at the Salk
Institute Biotechnology/Industrial Associates (SIBIA), P. pastoris leap-frogged
into a state-of-the-art molecular and cellular biological system for basic and
applied research.