Role of Lactic Acid Bacteria Phospho-β-Glucosidases during the Fermentation of Cereal by-Products

Abstract

Bioprocessing using lactic acid bacteria (LAB) is a powerful means to exploit plant-derived by-products as a food ingredient. LAB have the capability to metabolize a large variety of carbohydrates, but such metabolism only relies on few metabolic routes, conferring on them a high fermentation potential. One example of these pathways is that involving phospho-β-glucosidase genes, which are present in high redundancy within LAB genomes. This enzymatic activity undertakes an ambivalent role during fermentation of plant-based foods related to the release of a wide range of phenolic compounds, from their β-D-glycosylated precursors and the degradation of β-glucopyranosyl derived carbohydrates. We proposed a novel phenomic approach to characterize the metabolism drift of Lactiplantibacillus plantarum and Leuconostoc pseudomesenteroides caused by a lignocellulosic by-product, such as the brewers’ spent grain (BSG), in contrast to Rich De Man, Rogosa and Sharpe (MRS) broth. We observed an increased metabolic activity for gentiobiose, cellobiose and β-glucoside conjugates of phenolic compounds during BSG fermentation. Gene expression analysis confirmed the importance of cellobiose metabolism while a release of lignin-derived aglycones was found during BSG fermentation. We provided a comprehensive view of the important role exerted by LAB 6-phospho-β-glucosidases as well the major metabolic routes undertaken during plant-based fermentations. Further challenges will consider a controlled characterization of pbg gene expression correlated to the metabolism of β-glucosides with different aglycone moieties.

Phenolics Profile, Antioxidant Activity and Flavor Volatiles of Pear Juice: Influence of Lactic Acid Fermentation Using Three Lactobacillus Strains in Monoculture and Binary Mixture

“…TPC in fermented pear juice ranged from 337.98 (by Lh76) to 361.08 (by Lp90) mg GAE/L, which was higher than unfermented pear juice (323.37 mg GAE/L). The increase in TPC should be attributed to the hydrolysis of large polymeric phenolics into simple new phenolic compounds conducted by LAB strains [ 1 , 6 , 26 ]. TFC was decreased significantly during fermentation, especially for binary mixture of Lc37 and Lh76 fermentation, decreasing by 15.96%.…”

“…There has been a significant increase in the demand for probiotic functional foods in recent years because of their nutrition and health benefits [ 5 ]. Non-dairy based probiotic functional foods development is booming because of vegetarianism, lactose intolerance, and high cholesterol risks [ 6 ]. Fruits and vegetables are rich in nutrients, such as vitamins, dietary fiber, carotenoids, folate, etc., and are considered as promising vehicles of probiotic microorganisms [ 7 ].…”

“…Fruits and vegetables are rich in nutrients, such as vitamins, dietary fiber, carotenoids, folate, etc., and are considered as promising vehicles of probiotic microorganisms [ 7 ]. It has been demonstrated that lactic acid bacteria (LAB) can consume sugars as carbon sources to produce different metabolites, such as lactic acid, anti-hypertensive peptides, and exopolysaccharides [ 6 , 8 , 9 ]. Phenolics have been suggested to enhance the nutrition and sensory properties of fruit and vegetable products, and convert polyphenols to phenolic acids with lower molecular weight, which become more bioactive [ 8 , 10 , 11 ].…”

Fermentation Affects the Antioxidant Activity of Plant-Based Food Material through the Release and Production of Bioactive Components

“…Phospho-β-glucosidases plays a significant role during the fermentation of plant-based foods related to the release of phenolic compounds. Acin-Albiac et al characterized the metabolism of Lactiplantibacillus plantarum and Leuconostoc pseudomesenteroides during their fermentation with brewers’ spent grain and noted an increased metabolic activity for gentiobiose, cellobiose and β-glucoside conjugates of phenolic compounds during fermentation [ 69 ]. In addition, de Araújo et al investigated the hydrolytic potential of the enzymes of filamentous fungi isolated from the natural cocoa fermentation.…”

Microbial Metabolic Pathways and the “Fermented Plant Foods—Human Health” Axis

“…Their study highlighted metabolic pathways that may occur in addition to or in competition with dextran formation, and extended the knowledge on L. hordei exploitability and its ecological role during water kefir fermentation. Acin-Albiac et al [ 11 ] proposed an innovative phenomic approach to describe the metabolism drift of Lactiplantibacillus plantarum and Leuconostoc pseudomesenteroides induced by lignocellulosic-derived substrates originating from brewers’ spent grain (BSG), compared to a conventional growth medium. BSG constitute the most abundant by-product generated in the beer-brewing process and represent a current challenge within cereal by-products valorization due to the complexity of its indigestible polymers and anti-nutritional factors.…”