Conversion of hydroxycinnamic acids by Furfurilactobacillus milii in sorghum fermentations: Impact on profile of phenolic compounds in sorghum and on ecological fitness of Ff. milii.

Conversion of (poly)phenolic compounds in food fermentations by lactic acid bacteria: Novel insights into metabolic pathways and functional metabolites

“…Moreover, mutational disruption of esterases of hydroxycinnamic esters in Lp. plantarum and in F. milii did not alter the phenotype in food fermentations ( Gaur, 2022 , Gaur et al, in press ; Gaur et al, 2023 ), documenting that the activity of these esterases on the diversity of esters occurring in plants remains to be determined.…”

“…reuteri, Lm. fermentum Flavonoid and phenolic acid glycosidase, hydroxycinnamic acid esterase, -reductase and -decarboxylase, viny phenol reductase Naringenin-7- O -glucoside, eriodictyol-7- O -glucoside, coumaroyl-caffeoylglycerol, coumaroyl-feruloylglycerol, coumaroylglycerol, ferulic acid, caffeic acid, 3-deoxyanthocyanidins; Naringenin, eriodictyol, caffeic, p- coumaric acid, ferulic acid, dihydroferulic acid, vinyl catechol, ethyl catechol, pyrano-3-deoxyanthocyanidins, 3-deoxyanthocyanidin− vinylphenol adducts; ( Bai et al, 2014 ; Svensson et al, 2010 ; Gaur et al, 2023 ) Red quinoa L. acidophilus, Lc. casei, Lc.…”

“…Many strains, however, encode for multiple esterases or glycosyl hydrolases with complementary or overlapping substrate specificities ( Gaur, 2022 ; Landete et al, 2021 ; Theilmann et al, 2017 ), which makes the unambiguous assignment of genotype to phenotype challenging or impossible. Only few studies used isogenic mutants to confirm the activity of specific enzymes in food fermentations ( Gaur, 2022 ; Gaur et al, 2023 ) and data on the expression of genes in complex food substrates remains scarce. The identification of several genes related to metabolism of phenolic compounds since 2018 provides the necessary tools to address this limitation.…”

“…In sorghum fermentatioins, vinyl phenol adducts of 3-deoxyanthocyanidins and pyrano-3-deoxyanthocyanidins during are formed ( Bai et al, 2014 ). This conversion predominantly attributable to hydroxycinnamic acid decarboxylase activity of lactobacilli ( Gaur et al, 2023 ).…”

Experimental Evolution Reveals a Novel Ene Reductase That Detoxifies α,β-Unsaturated Aldehydes in Listeria monocytogenes

“…The ability to reduce hydroxycinnamic acids is widespread in heterofermentative lactobacilli, such as Furfuribacillus spp., probably because it diminishes their antimicrobial potency and because it allows for the conservation of extra energy from the fermentation of hexoses via the phosphoketolase pathway. Particularly in F. milii , the hydroxycinnamic acid reductase Par1 was shown to reduce the ene group of hydroxycinnamic acids and to contribute to fitness during the fermentation of sorghum ( 54 ). By analogy, the ability of L. monocytogenes to degrade α,β-unsaturated aldehydes may be an adaptation to grow on plant leaves, which are one of the various environments in which this organism thrives ( 55 ).…”