Within the Purple4Life project, Nofima contributes its expertise in fish feed formulation and production, fish nutrition and the evaluation of how functional ingredients such as purple phototrophic bacteria (PPB) influence fish performance, health, welfare and product...
Within the Purple4Life project, Comenius University, Faculty of Medicine (UNIBA), based in Bratislava, Slovakia, is an active participant in this European initiative. Our team contributes expertise in mitochondrial medicine, antioxidants, and oxidative stress. What is...
Within the European project Purple4Life, our team at the University of Antwerp studies how purple phototrophic bacteria can support sustainable, circular bioprocesses. These microbes are metabolically versatile, but their real value will depend on knowing exactly which conditions trigger the formation of high-value antioxidants.
My name is Arianna Reolon, and my PhD is centred on identifying those conditions. Our goal is to establish robust cultivation principles that move PPB-derived antioxidants from an interesting laboratory result to a credible, evidence-based biotechnological route.
In my first experiments I am developing a two-stage cultivation strategy using Cereibacter sphaeroides and Rhodobacter capsulatus strains isolated in-house. In the first stage, cultures are grown to late exponential phase under conditions that favour rapid and efficient biomass formation. In the second stage, the culture is shifted to a controlled stress environment to stimulate the synthesis of high-value antioxidants, particularly carotenoids and coenzyme Q10.
Carotenoids and coenzyme Q10 already play recognized roles in human and fish health. Carotenoids support antioxidant defense and immune function, while coenzyme Q10 contributes to mitochondrial energy balance and cardiovascular resilience. In aquaculture, these molecules improve pigmentation, growth and stress tolerance. Yet most current supplies come from synthetic or resource-intensive sources. If PPB can produce them efficiently from circular carbon streams, they offer a cleaner, more sustainable route to compounds with proven biological value.
Our team is motivated by developing microbial products that can genuinely serve society. We do not focus solely on production. We work at the interface of microbial biotechnology and sustainability, so our interest in PPB goes far beyond producing colorful molecules, we also examine potential applications in health, nutrition and other sectors, ensuring that any advances in cultivation can be translated into meaningful use cases.
Importantly, we challenge ourselves to remain evidence-driven. Many microbial products sound promising on paper. Our task is to test which ones actually perform, which ones can be produced consistently, and which ones can meet regulatory and safety expectations. The aim is not to add another exotic microbe to the literature but to build credible routes that could underpin future bio-based industries.
Next, we will cultivate PPB mixotrophically using CCU-derived organics such as ethanol or lactic acid to increase carbon efficiency. In parallel, we will evaluate greener extraction and quantification methods and begin mapping which applications these antioxidant-rich biomasses are best suited for.