期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：2006
卷号：52
期号：4
页码：256-260
DOI：10.3177/jnsv.52.256
出版社：Center for Academic Publications Japan
摘要：It is well known that some amino acids inhibit bacterial growth. L -Serine is known to inhibit the growth of Escherichia coli by inhibition of homoserine dehydrogenase (EC 1.1.1.3). It has been reported that this L -serine inhibition may be prevented by the addition of L -isoleucine or L -threonine to the medium. In our study, however, recovery of the growth inhibition of Escherichia coli by L -serine occurred in the presence of several amino acids, especially L -phenylalanine. In an attempt to further elucidate this inhibition mechanism, different intermediates of aromatic amino acid biosynthesis were added to the growth medium. Recovery from the inhibition did not occur in the presence of prephenate but did occur when phenylpyruvate was added to the medium. The specific activity of prephenate dehydratase decreased in cells grown in the presence of L -serine. However, L -serine did not inhibit in vitro prephenate dehydratase activity, and the expression of pheA , which encodes the prephenate dehydratase, was not depressed by L -serine. We suggest that L -serine acts via another inhibition mechanism. Although this inhibition mechanism has not been fully elucidated, our results suggest that the addition of L -serine to the growth medium inhibits prephenate dehydratase synthesis and thus affects L -phenylalanine biosynthesis.
