Development of Biopolyesters (PHA) as Part of the Swiss Priority Program in Biotechnology


  • Manfred Zinn HES-SO Valais-Wallis (University of Applied Sciences and Arts Western Switzerland Valais), Institute of Life Technologies, Route du Rawyl 47, CH-1950 Sion 2, Switzerland;, Email:





Biopolymers, Bioprocess, Cultivation, Nutrient limitation, Polyhydroxyalkanoates


The Swiss Priority Program in Biotechnology of the Swiss National Science Foundation that lasted between 1992 and 2001 had a boosting effect on many biotech disciplines and on the developments of polyhydroxyalkanoates (PHAs) in Switzerland in particular. The funding organization led by Prof. Oreste Ghisalba enabled a better understanding of the PHA biosynthesis and the development, as well as the implementation of novel bioprocesses (e.g. two-phase fermentations, multiple nutrient limited growth conditions, multi-stage chemostats, and product formation in different host organisms). However, production of PHA in Switzerland appeared to be impossible for cost reasons due to the strong competition from cheaper, petrol-based plastics. The recent reports on environmental issues with non-degradable plastics has triggered a general change in the perception of biodegradable plastics, giving them an added value and thus justifying a higher price. Ongoing research focuses on the sustainable production of PHAs using carbon waste streams, synthesis gas or even CO2