Acidogenic Fermentation of Brewers’ Spent Grain Monitored through Two-Dimensional Fluorescence Spectroscopy

Funding Information: This research was funded by national funds from the FCT─Fundação para a Ciência e a Tecnologia, I.P. through the project PTDC/BTA-BTA/31746/2017, in the scope of projects UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences─UCIBIO, project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy─i4HB, and the project UIDB/50016/2020 of the Associate Laboratory Centro de Biotecnologia e Química Fina─CBQF. This research was also funded by the Associate Laboratory for Green Chemistry─LAQV, which is financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020). E.C.G. gratefully acknowledges FCT for grant SFRH/BD/136300/2018. Publisher Copyright: © 2023 The Authors. Published by American Chemical Society.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.publishersversioninpres

Fouling of ion-exchange membranes during electrodialytic acid whey processing analysed by 2D fluorescence and FTIR spectroscopy

Funding Information: The authors would like to thank the staff at Hobro dairy for collection of acid whey samples. Also, special thanks to MemBrain s.r.o. and MEGA a.s. for providing us with the electrodialysis unit and the ion-exchange membranes. This present study is a part of the Platform for Novel Gentle Processing supported by the Dairy Rationalisation Fund (DDRF), Copenhagen University and Arla Foods. This work received support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the projects UIDB/50006/2020 and UIDP/50006/2020. Publisher Copyright: © 2023 The Author(s)Acid whey (AW), a by-product from the production of acidified dairy products, contains high amounts of lactic acid and minerals that can be recovered by electrodialysis (ED). To better understand the process and improve its efficiency, the objective of this study was to investigate fouling of ion-exchange membranes (IEMs) during ED of AW and concentrated AW by reverse osmosis (ROAW), underlimiting (ULCD), limiting (LCD) and overlimiting current density operating conditions (OLCD). The structure, hydrophobicity, and chemical composition of membranes showed differences regarding fouling on anion- (AEM) and cation- (CEM) exchange membranes facing the diluate and the concentrate, both for AW and ROAW. Furthermore, operating at OLCD tends to reduce fouling compared to ULCD, due to the expected generation of electroconvective vortices. 2D fluorescence spectroscopy and Fourier-transform infrared spectroscopy (FTIR) provided complementary and more detailed information regarding the fouling and efficiency of the cleaning procedure. The 2D fluorescence spectra showed that the AEM surfaces in contact with the diluate change more than those in contact with the concentrate. The FTIR analyses showed the presence of lactose and lactic acid on the AEM surfaces in contact with the concentrate, which could not be detected by fluorescence.publishersversioninpres

How does knowledge on the microbiome can help advancing the valorization of brewers' spent grain through volatile fatty acids production

info:eu-repo/semantics/publishedVersio

The microbiome of anaerobic granules during volatile fatty acid production is shaped by fluctuations in pH

info:eu-repo/semantics/publishedVersio

Fluctuations of the pH shape the microbiome of anaerobic granules during volatile fatty acids production

info:eu-repo/semantics/publishedVersio