RT Journal Article
T1 Tailoring non-axenic lactic acid fermentation from cheese whey permeate targeting a flexible lactic acid platform
A1 Delmoitié, Brecht
A1 Sakarika, Myrsini
A1 Rabaey, Korneel
A1 De Wever, Heleen
A1 Alberte Regueira, 
A1 Regueira López, Alberte
AB Lactic acid (LA) is an important biobased platform chemical, with potential applications in synthetising a wide range of chemical products or serving as feedstock for various bioprocesses. Industrial LA production via pure culture fermentation is characterized by high operational costs and utilizes food-grade sugars, thereby reducing the feasibility of LA applications. In this context, our research focussed on valorising the largest dairy side stream, cheese whey permeate, through the use of mixed microbial communities. We evaluated the effect of different operational parameters (temperature, pH and hydraulic retention time) in non-axenic fermentations on productivity, yield, concentration, optical purity, and community. Our findings revealed that operating at mildly thermophilic conditions (45 °C) resulted in highly selective LA production, and significantly augmented the LA yield, and productivity, compared to higher temperatures (50–55 °C). In addition, operating at circumneutral pH conditions (6.0–6.5) led to significantly increased the LA fermentation performance compared to the conventional acid pH conditions (≤5.5). This led to an unprecedented LA productivity of 27.4 g/L/h with a LA yield of 70.0% which is 2.5 times higher compared to previous reported maximum. Additionally, varying pH levels influenced the optical purity of LA: we achieved an optical L-LA purity of 98.3% at pH 6.0–6.5, and an optical D-LA purity of 91.3% at a pH of 5.5. A short hydraulic retention time of less than 12 h was crucial for selective LA production. This process also yielded a microbial biomass composed of 90.3–98.6% Lactobacillus delbrueckii, which could be potentially valorised as probiotic or protein ingredient in food or feed products. Our work shows that by careful selection of operational conditions, the overall performance can be significantly increased compared to the state-of-the-art. These results highlight the potential of non-sterile LA fermentation and show that careful selection of simple reactor operation parameters can maximize process performance. A preliminary assessment suggests that valorising EU cheese whey permeate could increase LA and poly-LA production by 40 and 125 times, respectively. This could also lead to the production of 4,000 kton protein-rich biomass, potentially reducing CO2 emissions linked to EU food and feed production by 4.87% or 2.77% respectively.
PB Elsevier
YR 2025
FD 2025
LK https://hdl.handle.net/10347/38040
UL https://hdl.handle.net/10347/38040
LA eng
NO Journal of Environmental Management Volume 373, January 2025, 123529
NO B.D. was supported by the Research Foundation Flanders (FWO-Vlaanderen; Grant number: 1S20323N). M.S. was supported by Ghent University (BOF.PDO.2021.0036.01). A.R. acknowledges the support of the Xunta de Galicia through a postdoctoral fellowship (ED481B-2021-012). A.R. belongs to a Galician Competitive Research Group (GRC ED431C 2021/37), cofunded by ERDF (EU).
DS Minerva
RD 27 abr 2026