Folates biosynthesis by Streptococcus thermophilus during growth in milk.

Folates biosynthesis by Streptococcus thermophilus during growth in milk. Food Microbiol. 2018 Feb;69:116-122 Authors: Meucci A, Rossetti L, Zago M, Monti L, Giraffa G, Carminati D, Tidona F Abstract The ability of folate-producer strains of Streptococcus thermophilus to accumulate folates and the expression of two target genes (folK and folP), involved in the folate biosynthesis, were studied during milk fermentation. An over-expression of folK took place only in the early phase of growth, whereas folP was mainly expressed in the mid log-phase of growth and declined thereafter. The accumulation of total folates, which was quantified by a microbiological assay, was strain-dependent. Two major forms of folates, i.e. tetrahydrofolate (THF) and 5-methyl-tetrahydrofolate (5-Met-THF), were identified and quantified by HPLC. With respect to the level accumulated by a weak folate producer (St 383), used as calibrator in the expression experiments and as control in folate quantification in milk, the strains St 563 and St 399 produced 5-Met-THF in amounts significantly higher than THF. The possibility of using selected folate-producer S. thermophilus strains as functional cultures for a bio-fortification of dairy products is discussed. PMID: 28941892 [PubMed - in process]
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research