Boosting aerobic microbial protein productivity and quality on brewery wastewater: Impact of anaerobic acidification, high-rate process and biomass age

Ruminations on sustainable and safe food: Championing for open symbiotic cultures ensuring resource efficiency, eco‐sustainability and affordability

“…For microorganisms, the notion of ‘feed’ does not make much sense, so only nitrogen and energy conversion efficiencies are presented, and not the commonly used ‘feed conversion ratio’, which can reach dispersed values depending on normative choices on feed and product moisture content, among others. For high‐rate aerobic heterotrophic bacteria (Papini et al., 2023 ), purple bacteria (Alloul et al., 2019 ; Spanoghe et al., 2021 ) and baker's yeast, the nitrogen conversion efficiency is assumed the same as for hydrogen and methane‐oxidizing bacteria, as these organisms all have low nitrogen affinity constants, and the energy conversion efficiency is estimated based on the chemical oxygen demand (COD) yield. *: based on only one study; **: in theory, when all input COD or H 2 is converted into biomass with the support of the phototropic route; N/A: not applicable as a pure photoautotrophic route.…”

“…For chemoorganoheterotrophs, biomass yield, CUE or FEE (for feed energy to edible energy conversion efficiencies) are all correlated, and reach their theoretical upper limit between 30% and around 60%, depending on the substrate (El Abbadi et al., 2019 ; Erickson et al., 2000 ; Mishra et al., 2020 ). On complex substrates like wastewater, the observed yield of high‐rate symbiotic cultures can even be higher due to biosorption, up to, for instance, maximum values up to 75% (Papini et al., 2023 ). Aerobically grown yeasts and filamentous fungi generally present lower CUE values (Table 1 ).…”