Whats left from the brew? Investigating residual barley proteins in spent grains for downstream valorization opportunities
Authors: Gregersen Echers, S., Mikkelsen, R. K., Abdul-Khalek, N., Queiroz, L. S., Hobley, T. J., Schulz, B. L., Overgaard, M. T., Jacobsen, C., Yesiltas, B.
The study provides an in‑depth proteomic characterization of brewer's spent grain (BSG) and tracks proteome dynamics during malting and mashing, revealing that 29% of identified proteins change in abundance and that B3‑Hordein dominates the BSG protein pool. BSG contains a high proportion of intracellular proteins and over 45% of its proteins are potential allergens or antinutritional factors, underscoring the need for targeted downstream processing to create safe, functional food ingredients.
The study examined how altering ethylene biosynthesis (ACO1) or perception (etr1.1) in a hybrid poplar (P. tremula × P. tremuloides T89) influences the assembly of root and shoot fungal and bacterial communities, using amplicon sequencing and confocal microscopy. Ethylene modulation had limited impact on the sterile plant metabolome but triggered distinct primary and secondary metabolic changes in microbe‑colonized plants, correlating with reduced fungal colonisation of shoots and increased root fungal colonisation, while arbuscular mycorrhizal fungi and bacterial communities were largely unchanged.
The study profiled the Arabidopsis apoplastic proteome during pattern‑triggered immunity induced by the flg22 peptide, using apoplastic washing fluid with minimal cytoplasmic contamination followed by LC‑MS/MS. Results showed consistent PTI‑specific enrichment and depletion of peptides, a bias toward ectodomain peptides of receptor‑like kinases, and increased abundance of the exosome marker tetraspanin 8, indicating heightened exosome levels during PTI.