A new research article authored by members of the PURPLE4LIFE consortium has been published in Bioresource Technology, addressing one of the central questions in the development of purple phototrophic bacteria (PPB) as a source of high-value compounds: how these...
The 19th IWA World Conference on Anaerobic Digestion (IWA AD19) was held in Valencia, Spain, from 9 to 13 June 2026, bringing together international experts in anaerobic digestion and resource recovery. The event included participation from the Universidad Rey Juan...
Researchers from Universidad Rey Juan Carlos, working within the Purple4Life consortium, have published in MethodsX an integrated analytical workflow for the extraction, isolation, identification and quantification of carotenoids produced by Rhodobacter capsulatus.
Carotenoids are among the pigments produced by purple phototrophic bacteria (PPB) and one of the compound families of interest for Purple4Life. However, their analysis and quantification in microbial cultures remain challenging: biological matrices are complex, and the commercial reference standards required for quantification are often expensive or of limited availability.
The team formed by Javier Llama, Sara Jerez, María Ventura, Amanda Prado, Daniel Puyol and Juan Antonio Melero (Universidad Rey Juan Carlos) proposes a reproducible workflow that addresses these limitations end-to-end.
Extraction is carried out under light-protected conditions. A thin-layer chromatography (TLC) screening step precedes column chromatography, which is used to isolate individual carotenoids. Structural assignment relies on UV–Vis spectroscopy, nuclear magnetic resonance (NMR) and LC-APCI-QTOF-HRMS, supported by exact-mass and isotopic-cluster evidence.
For quantification, the method replaces commercial standards with the Lambert–Beer law applied through compound-specific molar extinction coefficients, together with HPLC calibration curves built from carotenoid-enriched fractions isolated in the laboratory itself.
Reliable measurement is an essential step towards optimising Purple4Life’s processes for producing high-value compounds from purple phototrophic bacteria. This method equips the consortium with a robust analytical foundation for that work, and offers the wider scientific community a cost-effective alternative for the analysis of microbial carotenoids.
📄 Read the full publication: the article is available as an open-access publication in MethodsX. The work was also supported by the BIVALIA-CM project.