biostudies-literatureGutschmann BBundesministerium für Bildung und ForschungGerman Federal Ministry of Education and Research295-306https://www.ebi.ac.uk/biostudies/studies/S-EPMC9871520biostudies-literatureUnknown16(2)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. During laboratory-scale cultivations with Ralstonia eutropha Re2058/pCB113, 70% more PHA (45 g_PHA L^-1 ) and a 75% higher space-time yield (0.63 g_PHA L^-1  h^-1 ) were achieved compared to previously reported fermentations with solid WAF. During the development process, growth and PHA formation were monitored in real-time by in-line photon density wave spectroscopy. The process robustness was fMicrobial biotechnologyContinuous feeding strategy for polyhydroxyalkanoate production from solid waste animal fat at laboratory- and pilot-scale.PMC987152003Z22AN12031B0798ASchiewe TNeubauer PMaldonado Simoes MSchroter ESRiedel SLGutschmann BMunzberg MBockisch AfalseContinuous 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. During laboratory-scale cultivations with Ralstonia eutropha Re2058/pCB113, 70% more PHA (45 g_PHA L^-1 ) and a 75% higher space-time yield (0.63 g_PHA L^-1  h^-1 ) were achieved compared to previously reported fermentations with solid WAF. During the development process, growth and PHA formation were monitored in real-time by in-line photon density wave spectroscopy. The process robustness was f2023-01-01T00:00:00Z2023 Feb2025-04-04T13:37:01.553Z2025-04-04T13:37:01.553ZS-EPMC98715203592139810.1111/1751-7915.14104