Increased exopolysaccharide production in Lactococcus lactis due to increased levels of expression of the NIZO B40 eps gene cluster
Increased exopolysaccharide production in Lactococcus lactis due to increased levels of expression of the NIZO B40 eps gene cluster
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DOI：
10.1128/aem.69.8.5029-5031.2003
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发表时间：
2003-08-01
影响因子：
4.4
通讯作者：
Kleerebezem, M
中科院分区：
文献类型：
--
作者：
Boels, IC;van Kranenburg, R;Kleerebezem, M
胞外多糖（EPS）在发酵食品的流变学和质构中起着重要作用。这是第一个报告表明，在乳酸乳球菌中的一个完整的eps基因簇的同源过表达导致EPS生产水平的增加。EPS质粒拷贝数增加九倍，导致eps表达水平增加近三倍，从而使NIZO B40 EPS产量水平增加近四倍。先前报道，EPS前体水平的增加并不影响NIZO B40 EPS生产水平。然而，目前的结果表明，最大NIZO B40 EPS生产水平是由eps基因簇的表达产物的活性水平，而不是由EPS前体的水平限制。
Exopolysaccharides (EPS) play an important role in the rheology and texture of fermented food products. This is the first report demonstrating that homologous overexpression of a complete eps gene cluster in Lactococcus lactis leads to increased EPS production levels. A ninefold-elevated EPS plasmid copy number led to an almost threefold increase in the eps expression level, resulting in an almost fourfold increase in the NIZO B40 EPS production level. It was previously reported that increased EPS precursor levels did not influence NIZO B40 EPS production levels. However, the present results indicate that the maximal NIZO B40 EPS production level is limited by the activity level of the expression products of the eps gene cluster rather than by the level of EPS precursors.