Methionine utilization by bifidobacteria: possible existence of a reverse transsulfuration pathway

Abstract

Although bifidobacteria are already widely used as beneficial microbes with health-promoting effects, their amino acid utilization and metabolism are not yet fully understood. Knowledge about the metabolism of sulfur-containing amino acids in bifidobacteria is especially limited. In this study, we tested the methionine utilization ability of several bifidobacterial strains when it was the sole available sulfur source. Although bifidobacteria have long been predominantly considered to be cysteine auxotrophs, we showed that this is not necessarily the case. Table S1 Components of bifidobacterial minimal medium (BMM) Components Concentration (per Liter) Glucose 20 g NaCl 9.0 g CH 3 COONa 5.0 g KH 2 PO 4 4.5 g Na 2 CO 3 400 mg (NH 4) 2 SO 4 400 mg MgSO 4 ・7H 2 O 409 mg CaCl 2 ・2H 2 O 250 mg MnCl 2 ・5H 2 O 100 mg Isoleucine 64.5 mg Tyrosine 87 mg Sodium ascorbate 340 mg Inositol 1.4 mg p-Aminobenzoic acid 0.8mg Nicotinic acid 0.6 mg Choline 0.3 mg Pantothenic acid (Ca) 0.3 mg Riboflavin 0.12 mg Pyridoxine・HCl 0.04 mg Folic acid 1.5 g Cysteine or Methionine 242 or 298 mg (2 mM) pH6.5

Urolithins: potential biomarkers of gut dysbiosis and disease stage in Parkinson's patients

“…Consistent with this, bifidobacteria have long been known to be cysteine auxotrophs, although various bifidobacteria strains can also use methionine when it is the only available sulphur source. 45 A previous study with a colitis rat model also showed increased cysteine and methionine metabolism. 46 In the present study, the increased levels of cysteine and methionine metabolism, as well as glutathione metabolism in PD(−) and SPD, could result in the biosynthesis of advantageous compounds for bacteria against oxidative stress, a feature of the inflammatory environment.…”

Biomarkers and Utility of the Antioxidant Potential of Probiotic Lactobacilli and Bifidobacteria as Representatives of the Human Gut Microbiota

“…The AO ability of probiotic bacteria can be considered to be a result of the ability to produce amino acids in high quantities. Bifidobacteria exhibit the ability to produce amino acids with AO properties, such as cysteine and methionine [131]. Some bifidobacteria possess the genes involved in the reverse transsulfuration pathway, which produces cysteine from methionine using homocysteine as an intermediate.…”

“…Some bifidobacteria possess the genes involved in the reverse transsulfuration pathway, which produces cysteine from methionine using homocysteine as an intermediate. There are genes such as ahcY that encode an S-adenosylhomocysteinase, and luxS, which encodes a S-ribosylhomocysteinase for the S-adenosyl methionine cycle [130,131].…”

Prebiotic Activity of Vaginal Lactobacilli on Bifidobacteria: from Concept to Formulation

“…Moreover, aromatic amino acids (tryptophan and tyrosine), found mainly in BC17 CFSs at 7 h and 13 h, can be metabolized by Bifidobacterium species and converted into their lactic acid derivatives ( 29 ). Sulfur-containing amino acids are also required for the growth of bifidobacteria; indeed, some Bifidobacterium species (i.e., B. bifidum ) have been reported to be cysteine auxotrophs, while others can synthesize cysteine from methionine ( 30 ). In this regard, the presence of methionine and cysteine in BC17 CFSs (with the latter being present mainly in BC17 CFS at 7 h) can sustain the proliferation of bifidobacteria.…”