Browsing by Author "Costa, Eunice"
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- Acidogenic fermentation of brewers’ spent grain monitored through two-dimensional fluorescence spectroscopyPublication . Guarda, Eliana C.; Costa, Eunice; Gil, Cátia; Amorim, Catarina L.; Galinha, Claudia F.; Duque, Anouk F.; Castro, Paula M. L.; Reis, Maria A. M.Biological systems are commonly controlled and monitored through offline and time-consuming tools, which often impairs an effective and real-time response to counteract system disturbances. The feasibility of using two-dimensional (2D) fluorescence spectroscopy as a non-invasive, non-destructive, and real-time procedure to monitor the acidogenic fermentation of brewer’s spent grain (BSG) in a granular sludge reactor was evaluated. For that, the effect of pH fluctuations on the system response was used as a model to ascertain the 2D fluorescence spectroscopy applicability to monitor the process performance, namely, to predict the fermentation products (FP) and the soluble protein (SProt) concentrations in the effluent stream through mathematical analysis. The pH fluctuations over the course of the reactor’s operation altered the granules’ microbiome composition, leading to different effluent FP profiles. Fluorescence excitation–emission matrices (EEMs) were used with projection to latent structures (PLS) modeling to predict the FP and SProt concentrations in the effluent with average errors below 0.75 and 0.43 g L–1, respectively. Both models were able to capture the tendency of the data even when the accuracy of prediction was not so high. The combined approach of using 2D fluorescence spectroscopy and mathematical analysis seemed promising for real-time monitoring of the acidogenic fermentation of complex substrates.
- Fluctuations of the pH shape the microbiome of anaerobic granules during volatile fatty acids productionPublication . Guarda, Eliana C.; Costa, Eunice; Gil, Cátia; Amorim, Catarina L.; Galinha, Cláudia F.; Duque, Anouk F.; Castro, Paula M. L.; Reis, Maria A. M.
- How does knowledge on the microbiome can help advancing the valorization of brewers' spent grain through volatile fatty acids productionPublication . Guarda, Eliana C.; Costa, Eunice; Galinha, Cláudia F.; Gil, Cátia; Amorim, Catarina L.; Duque, Anouk F.; Castro, Paula; Reis, Maria A. M.
- The microbiome of anaerobic granules during volatile fatty acid production is shaped by fluctuations in pHPublication . Guarda, Eliana C.; Costa, Eunice; Gil, Cátia; Galinha, Cláudia F.; Amorim, Catarina L.; Duque, Anouk F.; Castro, Paula M. L.; Reis, Maria A. M.
- Valorization of brewery waste through polyhydroxyalkanoates production supported by a metabolic specialized microbiomePublication . Carvalheira, Mónica; Amorim, Catarina L.; Oliveira, Ana Catarina; Guarda, Eliana C.; Costa, Eunice; Teixeira, Margarida Ribau; Castro, Paula M. L.; Duque, Anouk F.; Reis, Maria A. M.Raw brewers’ spent grain (BSG), a by-product of beer production and produced at a large scale, presents a composition that has been shown to have potential as feedstock for several biological processes, such as polyhydroxyalkanoates (PHAs) production. Although the high interest in the PHA production from waste, the bioconversion of BSG into PHA using microbial mixed cultures (MMC) has not yet been explored. This study explored the feasibility to produce PHA from BSG through the enrichment of a mixed microbial culture in PHA-storing organisms. The increase in organic loading rate (OLR) was shown to have only a slight influence on the process performance, although a high selectivity in PHA-storing microorganisms accumulation was reached. The culture was enriched on various PHA-storing microorganisms, such as bacteria belonging to the Meganema, Carnobacterium, Leucobacter, and Paracocccus genera. The enrichment process led to specialization of the microbiome, but the high diversity in PHA-storing microorganisms could have contributed to the process stability and efficiency, allowing for achieving a maximum PHA content of 35.2 ± 5.5 wt.% (VSS basis) and a yield of 0.61 ± 0.09 CmmolPHA/CmmolVFA in the accumulation assays. Overall, the production of PHA from fermented BSG is a feasible process confirming the valorization potential of the feedstock through the production of added-value products.