From dairy waste to butyric acid: Scaling the valorization process.

To move towards a circular dairy sector and reduce its environmental impact, sustainable management of its by-products is essential. This study presents a novel approach to valorize milk permeate through the production of butyric acid. Key operating parameters, including hydraulic retention time (HRT) and pH, were tested at a laboratory scale and the best conditions were validated at a pre-industrial scale in a dairy factory.

Optimising medium chain carboxylate production in xylan mixed-culture monofermentation.

This work investigates the optimization of medium-chain carboxylate (MCC) production through xylan mixed-culture monofermentation. The pH screening in batch assays showed that the hydrolysis stage and selectivity towards MCC precursors were optimised at pH 6. Subsequently, a continuous stirred tank reactor (CSTR) and a Sequential Batch Reactor (SBR) were operated at different Hydraulic Retention Times (HRT), revealing that the SBR at HRT 2 days yielded the highest caproic acid since lactic acid availability and chain elongation process were balanced.

Exploring macroalgae biorefinery: Extraction of bioactive compounds and production of volatile fatty acids.

Macroalgae have gained significant attention in recent research owing to their potential as novel food source and their noteworthy nutritional properties. However, a substantial amount of these macroalgae accumulates along the coast without being utilized, highlighting the need for proper treatment and disposal methods to mitigate secondary pollution effects. Previous studies on macroalgae have primarily focused on extracting bioactive compounds or anaerobic digestion processes to produce methane or volatile fatty acids (VFA), with observed improvements following different pre-treatments.

Altering operational conditions during protein fermentation to volatile fatty acids modifies the associated bacterial community.

In recent years, the production of volatile fatty acids (VFA) through mixed culture fermentation (MCF) has been gaining attention. Most authors have focused on the fermentation of carbohydrates, while other possible substrates, such as proteins, have not been considered. Moreover, there is little information about how operational parameters affect the microbial communities involved in these processes, even though they are strongly related to reactor performance and VFA selectivity.