COMPARATIVE STUDIES ON SYNTHESIS OF WATER-SOLUBLE VITAMINS AMONG HUMAN SPECIES OF BIFIDOBACTERIA
COMPARATIVE STUDIES ON SYNTHESIS OF WATER-SOLUBLE VITAMINS AMONG HUMAN SPECIES OF BIFIDOBACTERIA
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DOI：
10.1080/00021369.1985.10866683
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发表时间：
1985-01-01
期刊：
影响因子：
--
通讯作者：
MUTAI, M
中科院分区：
文献类型：
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作者：
DEGUCHI, Y;MORISHITA, T;MUTAI, M
The ability of bifidobacteria to synthesize 6 water-soluble vitamins (thiamine, folic acid, nicotinic acid, pyridoxime, vitamin B12 and riboflavin) was systematically investigated with 24 strains of 5 spp. derived from human feces. The vitamins synthesized were determined as those accumulated in cultures grown in a semi-synthetic medium. For the vitamins other than vitamin B12 and riboflavin, extracellular liberation was also examined with the supernatant fluids obtained after removing cells from the cultures. Many strains of the bifidobacteria investigated could indeed synthesize 5 of the vitamins, the exception being riboflavin. A large portion of each of the vitamins synthesized was excreted into the medium. The concentrations of the vitamins, especially thiamine, nicotinic acid and folic acid, accumulated varied widely among different species or strains. On the basis of the results, these bifidobacteria could be divided into 3 general types according to the abilities to accumulate thiamine, nicotinic acid and folic acid. These 3 vitamins were accumulated in all the strains of Bifidobacterium bifidum and B. infantis, and in many strains of B. breve and B. longum, but the vitamin concentrations were significantly higher in the former species (higher-accumulators) than in the latter species (lower-accumulators). None of these 3 vitamins were detected in most strains of B. adolescentis, or in some strains of B. breve and B. longum (non-accumulators). Non-accumulator strains of B. adolescentis required thaimine and nicotinic acid for maximal growth in a complete synthetic medium. Further studies on thiamine synthesis revealed that the addition of exogenous thiamine to the medium significantly reduced the level of thiamine accumulated in a culture of a lower-accumulator strain of B. longum but did not affect the vitamin level in a higher-accumulator strain of B. bifidum. These findings were discussed in relation to the vitamin biosynthesis and its regulation in bacteria.
