Weikert C, Sauer U, Bailey J E
Institute of Biotechnology, ETH Zürich, CH-8093 Zürich, Switzerland.
Biotechnol Bioeng. 1998 Aug 5;59(3):386-91. doi: 10.1002/(sici)1097-0290(19980805)59:3<386::aid-bit16>3.0.co;2-c.
Periplasmic secretion of overexpressed Bacillus stearothermophilus alpha-amylase was analyzed in batch and fed-batch cultivations of Escherichia coli MG1655:pCSS4-p and the mutant strain CWML2:pCSS4-p. Under all conditions investigated, growth and product formation of MG1655:pCSS4-p were severely impaired by heterologous protein expression and/or processing, while E. coli CWML2:pCSS4-p was found to be more robust and to accumulate 2- to 3-fold higher maximum alpha-amylase levels. While this strain is itself potentially interesting for applications, its properties also illustrate the potential of the selection procedure that was employed to obtain it from its progenitor MG1655 (Weikert, C., Sauer, U., Bailey, J. E., 1997. Microbiol. 143: 1567-1574. Application of this procedure to existing industrial strains may lead to significantly improved process organisms.
在大肠杆菌MG1655:pCSS4-p和突变株CWML2:pCSS4-p的分批培养和补料分批培养中，分析了过表达的嗜热脂肪芽孢杆菌α-淀粉酶的周质分泌情况。在所研究的所有条件下，异源蛋白表达和/或加工严重损害了MG1655:pCSS4-p的生长和产物形成，而发现大肠杆菌CWML2:pCSS4-p更具稳健性，积累的最大α-淀粉酶水平高2至3倍。虽然该菌株本身在应用方面可能具有吸引力，但其特性也说明了从其亲本MG1655获得该菌株所采用的选择程序的潜力（Weikert, C., Sauer, U., Bailey, J. E., 1997. Microbiol. 143: 1567 - 1574）。将该程序应用于现有的工业菌株可能会显著改善工艺微生物。
