Biotechnological Production of Phenyllactic Acid and Biosurfactants from Trimming Vine Shoot Hydrolyzates by Microbial Coculture Fermentation

Coculture fermentations show advantages for producing food additives from agroindustrial wastes, considering that different specified microbial strains are combined to improve the consumption of mixed sugars obtained by hydrolysis. This technology dovetails with both the growing interest of consumers towards the use of natural food additives and with stricter legislations and concern in developed countries towards the management of wastes. The use of this technology allows valorization of both cellulosic and hemicellulosic fractions of trimming vine shoots for the production of lactic acid (LA), phenyllactic acid (PLA), and biosurfactants (BS). This work compares the study of the potential of hemicellulosic and cellulosic fractions of trimming vine shoots as cheaper and renewable carbon sources for PLA and BS production by independent or coculture fermentations. The highest LA and PLA concentrations, 43.0 g/L and 1.58 mM, respectively, were obtained after 144 h during the fermentation of hemicellulosic sugars and simultaneous saccharification and fermentation (SSF) carried out by cocultures of Lactobacillus plantarum and Lactobacillus pentosus. Additionally, cell-bond BS decreased the surface tension (ST) in 17.2 U; meanwhile, cell-free supernatants (CFS) showed antimicrobial activity against Salmonella enterica and Listeria monocytogenes with inhibition halos of 12.1 +/- 0.6 mm and 11.5 +/- 0.9 mm, respectively.