Pekilo process – history

Pekilo process is a pioneering solution developed in Finland in the 1970s for production of single cell protein. The process was operated at industrial scale over a decade.

During the 1950s and 1960s the world was widely believed to be running out of protein. Especially developing countries were predicted to face an insurmountable challenge to close the “World Protein Gap” while feeding their rapidly growing populations. This spurred the development of novel ways of producing protein, including what is generally known as single cell protein (SCP) – the cultivation of micro-organisms for use as food and feed. Both in the West and in the former USSR, significant investments were made into producing SCP, surprisingly mainly from fossil raw materials such as natural gas and methanol.

© Gösta Serlachiuksen taidesäätiö, Mänttä Serlachius-museot, Kuva-arkisto.

In Finland, a parallel development program took place: The pulp and paper industry invested heavily to develop a technology to convert side streams from sulfite wood pulping into SCP. The program uncovered a micro-organism, Paecilomyces variotii, uniquely capable of producing protein-rich SCP from dilute, heterogeneous and inhibitory organic side streams. After more than 15 years of R&D, the process was taken into industrial use, and operated at two sites, Jämsänkoski and Mänttä, each with an annual production capacity of 10 000 tons. Under the trade name “Pekilo”, the mycoprotein product was successfully used in pig and poultry feed formulations for well over a decade.

Eventually, as a consequence of the Green Revolution and the decline in population growth in emerging economies, fears of a “World Protein Gap” began to fade. At the same time, developments in pulp production technology gradually lead to the replacement of sulfite pulping with Kraft pulping in Finland. Interest in single cell protein waned and the Mänttä Pekilo plant finally closed its doors in 1992, and memory of the process began to fade.