Role of cysteine in the improvement of γ-aminobutyric acid production by nonproteolytic Levilactobacillus brevis in coculture with Streptococcus thermophilus was written by Xiao, Tingting;Shah, Nagendra P.. And the article was included in Journal of Dairy Science in 2022.Reference of 54-47-7 The following contents are mentioned in the article:
Previous research has showed that nonproteolytic Levilactobacillus brevis 145 (L) in coculture with Streptococcus thermophilus 1275 (S), not Lactobacillus delbrueckii ssp. bulgaricus (Lbu), was able to produce γ-aminobutyric acid (GABA) during milk fermentation in the presence of monosodium glutamate (MSG). It was assumed that differences of casein hydrolysis patterns between Strep. thermophilus 1275 and L. bulgaricus caused the phenomenon. Moreover, the GABA content was low and residual MSG was high in SL-fermented milk. In our research, comparison of peptide profiles determined by liquid chromatog./tandem mass spectrometry showed that αS2-casein, β-casein, and κ-casein degradation by L. bulgaricus and Strep. thermophilus varied. Importantly, the peptide number in the L and Lbu coculture group increased compared with the Lbu monoculture group, whereas the peptide number in the SL coculture group decreased in comparison with S monoculture group, suggesting that L. bulgaricus was not able to provide peptides for the growth of Lb. brevis 145. Furthermore, we found that after supplementation with cysteine (50 mg/L) during milk fermentation by SL, 10 g/L MSG was converted into 4.8 g/L GABA with a min. level of residual MSG, viable cell counts of Lb. brevis and lactic acid production were increased, and the casein hydrolysis pattern was not influenced. Moreover, sulfhydryl group-containing chems. including cystine, reduced glutathione, and oxidized glutathione showed effects similar to that of cysteine in improving GABA production Finally, when L. bulgaricus YIB2 was combined with SL, supplementation of cysteine was also able to significantly improve GABA production This study involved multiple reactions and reactants, such as (4-Formyl-5-hydroxy-6-methylpyridin-3-yl)methyl dihydrogen phosphate (cas: 54-47-7Reference of 54-47-7).
(4-Formyl-5-hydroxy-6-methylpyridin-3-yl)methyl dihydrogen phosphate (cas: 54-47-7) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.Reference of 54-47-7