GoodByO seeks at creating a new generation multi-commodities biorefinery based on food waste, biogenic CO2, and bioprocess wastewaters for resource-efficient valorization of sustainable feedstocks. GoodByO will apply this visionary concept at ChainCraft BV bio-plant by valorizing its gaseous and liquid side-streams as zero-cost feedstocks. By exploiting the metabolic diversity of microbial catalysts, four different microbial factories (MF) will be developed: -MF1: open culture chain elongation process for bio-octanoic acid production; -MF2: gas fermentation process for bio-hexanol production from biogas and green H2; -MF3: novel anaerobic photoautotrophic biogas desulfurization process; - MF4: wastewaters-based mixotrophic microalgal process for high-value carotenoids production. The project target relies in the validation of long-term production stability of the developed bioprocesses at TRL5, using real feedstocks, to provide transferable outcomes for further scale-up at higher TRLs. GoodByO will also design an in silico 100% renewable energy system capable of sustaining the fluctuating demand of the integrated biorefinery over time, by adopting biomethanation process as grid-balancing system. GoodByO targets to produce biobased products meeting market requirements at cost-competitive selling price with benchmarks, to boost end users companies in substituting fossil- and palm-oil based products with biobased ones. The successful scale-up and the market penetration of GoodByO processes will strongly increase EU global leadership in the Manufacturing biotech-Industry while advancing CO2-utilizing biotechnologies for developing a carbon-negative economy.