@phdthesis{Hammel2024,
  author    = {Hammel, Alexander},
  title     = {Establishing the red microalga Porphyridium purpureum as a novel platform for the production of recombinant proteins},
  doi       = {10.25932/publishup-63270},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-632709},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 159},
  year      = {2024},
  abstract  = {Microalgae have been recognized as a promising green production platform for recombinant proteins. The majority of studies on recombinant protein expression have been conducted in the green microalga C. reinhardtii. While promising improvement regarding nuclear transgene expression in this alga has been made, it is still inefficient due to epigenetic silencing, often resulting in low yields that are not competitive with other expressor organisms. Other microalgal species might be better suited for high-level protein expression, but are limited in their availability of molecular tools. The red microalga Porphyridium purpureum recently emerged as candidate for the production of recombinant proteins. It is promising in that transformation vectors are episomally maintained as autonomously replicating plasmids in the nucleus at a high copy number, thus leading to high expression values in this red alga. In this work, we expand the genetic tools for P. purpureum and investigate parameters that govern efficient transgene expression. We provide an improved transformation protocol to streamline the generation of transgenic lines in this organism. After being able to efficiently generate transgenic lines, we showed that codon usage is a main determinant of high-level transgene expression, not only at the protein level but also at the level of mRNA accumulation. The optimized expression constructs resulted in YFP accumulation up to an unprecedented 5\% of the total soluble protein. Furthermore, we designed new constructs conferring efficient transgene expression into the culture medium, simplifying purification and harvests of recombinant proteins. To further improve transgene expression, we tested endogenous promoters driving the most highly transcribed genes in P. purpureum and found minor increase of YFP accumulation. We employed the previous findings to express complex viral antigens from the hepatitis B virus and the hepatitis C virus in P. purpureum to demonstrate its feasibility as producer of biopharmaceuticals. The viral glycoproteins were successfully produced to high levels and could reach their native confirmation, indicating a functional glycosylation machinery and an appropriate folding environment in this red alga. We could successfully upscale the biomass production of transgenic lines and with that provide enough material for immunization trials in mice that were performed in collaboration. These trials showed no toxicity of neither the biomass nor the purified antigens, and, additionally, the algal-produced antigens were able to elicit a strong and specific immune response. The results presented in this work pave the way for P. purpureum as a new promising producer organism for biopharmaceuticals in the microalgal field.},
  language  = {en}
}
@phdthesis{GreweSalfeld2020,
  author    = {Grewe-Salfeld, Mirjam},
  title     = {Biohacking, bodies and do-it-yourself},
  series = {American Culture Studies ; 36},
  journal   = {American Culture Studies ; 36},
  publisher = {transcript Verlag},
  address   = {Bielefeld},
  isbn      = {978-3-8376-6004-3},
  school      = {Universit{\"a}t Potsdam},
  pages     = {314},
  year      = {2020},
  abstract  = {From self-help books and nootropics, to self-tracking and home health tests, to the tinkering with technology and biological particles - biohacking brings biology, medicine, and the material foundation of life into the sphere of »do-it-yourself«. This trend has the potential to fundamentally change people's relationship with their bodies and biology but it also creates new cultural narratives of responsibility, authority, and differentiation. Covering a broad range of examples, this book explores practices and representations of biohacking in popular culture, discussing their ambiguous position between empowerment and requirement, promise and prescription.},
  language  = {en}
}