The biotechnological development of purple phototrophic bacteria (PPB) focuses on resource recovery from waste sources, contributing to a circular bioeconomy. The technology is being scaled-up. However, technological implementation faces several challenges, such as:

  • Knowledge transfer from pure to mixed cultures
  • Obtaining fundamental knowledge on nutrients uptake pathways
  • Developing mechanistic models
  • Steering cultures to selective and stable communities
  • Defining the targeted waste streams
  • Optimizing culture conditions based on light transfer
  • Optimizing downstream processing to extract products
  • Developing techno-economic, social and environmental life cycle assessments.
  • A holistic and multidisciplinary approach is required to overcome these bottlenecks. The combined efforts of basic and applied scientists and technologists from the industrial sector improve this emerging technology’s competitiveness in the EU, ultimately leading to technology deployment and product commercialization.

PURPLEGAIN aims to create a European network to share information, facilitating technology and knowledge transfer between the academic and industrial sectors, related to PPB applications for resource recovery from organic waste sources. Resource recovery includes wastewater or organic waste, open or closed environments, in single or chain processes. The network associates fundamental-focused and applied-research groups, improving lab-scale technology optimization through mechanistic modeling. It benefits the technology transfer from applied-research groups to industry, considerably improving process design.

PURPLEGAIN also aims to create a database for techno-economic, social and environmental impact studies, which facilitates the marketability of both the PPB-based technologies and the products to extract. Some focused products are polyhydroxyalkanoates, single-cell proteins, biomass for energy, biomass as fertilizer, biohydrogen, carotenoids, terpenoids, organic acids, coenzyme Q10, and 5-aminolevulinic acid.

CA21146 - Fundamentals and applications of purple bacteria biotechnology for resource recovery from waste (PURPLEGAIN)

Action keywords

  • Purple phototrophic bacteria
  • Resource recovery from waste
  • Bioreactor design and processing
  • Bioeconomy and Circular Economy
  • Development of novel bioproducts.



COST (European Cooperation in Science and Technology) is a funding agency for research and innovation networks. Our Actions help connect research initiatives across Europe and enable scientists to grow their ideas by sharing them with their peers. This boosts their research, career and innovation.