Continuous feeding strategy for polyhydroxyalkanoate production from solid waste animal fat at laboratory- and pilot-scale.

Bioconversion of waste animal fat (WAF) to polyhydroxyalkanoates (PHAs) is an approach to lower the production costs of these plastic alternatives. However, the solid nature of WAF requires a tailor-made process development. In this study, a double-jacket feeding system was built to thermally liquefy the WAF to employ a continuous feeding strategy.

Sterol synthesis and cell size distribution under oscillatory growth conditions in Saccharomyces cerevisiae scale-down cultivations.

Physiological responses of yeast to oscillatory environments as they appear in the liquid phase in large-scale bioreactors have been the subject of past studies. So far, however, the impact on the sterol content and intracellular regulation remains to be investigated. Since oxygen is a cofactor in several reaction steps within sterol metabolism, changes in oxygen availability, as occurs in production-scale aerated bioreactors, might have an influence on the regulation and incorporation of free sterols into the cell lipid layer.

Tools for the determination of population heterogeneity caused by inhomogeneous cultivation conditions.

Population heterogeneity among a microbial culture can occur in various stages of a bioprocess. When a nutrient-limited fed-batch process is applied in the large scale, gradient formation (e.g.