Department of Food Sciences and Technology, University of Natural Resources and Life Sciences, Vienna, Austria.
J Agric Food Chem. 2011 May 25;59(10):5617-24. doi: 10.1021/jf104755r. Epub 2011 Apr 29.
Food-grade gene expression systems for lactic acid bacteria are useful for applications in the food industry. We describe a new food-grade host/vector system for Lactobacillus plantarum based on pSIP expression vectors and the use of the homologous alanine racemase gene (alr) as selection marker. A new series of expression vectors were constructed by exchanging the erythromycin resistance gene (erm) in pSIP vectors by the L. plantarum WCFS1 alr gene. The vectors were applied for the overexpression of β-galactosidase genes from L. reuteri L103 and L. plantarum WCFS1 in an alr deletion mutant of L. plantarum WCFS1. The expression levels obtained in this way, i.e. without the use of antibiotics, were comparable to the levels obtained with the conventional system based on selection for erythromycin resistance. The new system is suitable for the production of ingredients and additives for the food industry.
用于乳酸菌的食品级基因表达系统在食品工业中有广泛的应用。我们描述了一种新的基于 pSIP 表达载体和使用同源丙氨酸消旋酶基因 (alr) 作为选择标记的植物乳杆菌食品级宿主/载体系统。通过将 pSIP 载体中的红霉素抗性基因 (erm) 替换为植物乳杆菌 WCFS1 的 alr 基因，构建了一系列新的表达载体。这些载体被应用于在植物乳杆菌 WCFS1 的 alr 缺失突变体中过量表达来自罗伊氏乳杆菌 L103 和植物乳杆菌 WCFS1 的β-半乳糖苷酶基因。以这种方式获得的表达水平，即不使用抗生素，与基于红霉素抗性选择的常规系统相当。该新系统适用于食品工业中成分和添加剂的生产。
