Burgess Catherine, O'connell-Motherway Mary, Sybesma Wilbert, Hugenholtz Jeroen, van Sinderen Douwe
Department of Microbiology, Biosciences Institute, National University of Ireland, Cork, Ireland.
Appl Environ Microbiol. 2004 Oct;70(10):5769-77. doi: 10.1128/AEM.70.10.5769-5777.2004.
This study describes the genetic analysis of the riboflavin (vitamin B(2)) biosynthetic (rib) operon in the lactic acid bacterium Lactococcus lactis subsp. cremoris strain NZ9000. Functional analysis of the genes of the L. lactis rib operon was performed by using complementation studies, as well as by deletion analysis. In addition, gene-specific genetic engineering was used to examine which genes of the rib operon need to be overexpressed in order to effect riboflavin overproduction. Transcriptional regulation of the L. lactis riboflavin biosynthetic process was investigated by using Northern hybridization and primer extension, as well as the analysis of roseoflavin-induced riboflavin-overproducing L. lactis isolates. The latter analysis revealed the presence of both nucleotide replacements and deletions in the regulatory region of the rib operon. The results presented here are an important step toward the development of fermented foods containing increased levels of riboflavin, produced in situ, thus negating the need for vitamin fortification.
本研究描述了乳酸乳球菌乳脂亚种NZ9000中核黄素（维生素B2）生物合成（rib）操纵子的遗传分析。通过互补研究以及缺失分析对乳酸乳球菌rib操纵子的基因进行了功能分析。此外，利用基因特异性基因工程来检测rib操纵子的哪些基因需要过表达才能实现核黄素的过量生产。通过Northern杂交、引物延伸以及对玫瑰黄素诱导的核黄素过量生产的乳酸乳球菌分离株的分析，研究了乳酸乳球菌核黄素生物合成过程的转录调控。后一项分析揭示了rib操纵子调控区域中存在核苷酸替换和缺失。本文给出的结果是朝着开发原位生产核黄素水平升高的发酵食品迈出的重要一步，从而无需进行维生素强化。
