Veening J-W, Smits W K, Hamoen L W, Kuipers O P
Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Haren, The Netherlands.
J Appl Microbiol. 2006 Sep;101(3):531-41. doi: 10.1111/j.1365-2672.2006.02911.x.
Understanding the basis for the heterogeneous (or bistable) expression patterns of competence development and sporulation in Bacillus subtilis.
Using flow cytometric analyses of various promoter-GFP fusions, we have determined the single-cell gene expression patterns of competence development and initiation of sporulation in a chemically defined medium (CDM) and in biofilms.
We show that competence development and initiation of sporulation in a CDM are still initiated in a bistable manner, as is the case in complex media, but are sequential in their timing. Furthermore, we provide experimental proof that competence and sporulation can develop under conditions that normally do not trigger these processes.
Some pathogens are able to develop natural competence, which is a serious medical problem with the increased acquired multi-drug resistance of these organisms. Another adaptive microbial response is spore formation. Because of their heat resistance and hydrophobicity, spores of a variety of species are of major concern for the food industry. Using the model organism B. subtilis, we show that competence development and sporulation are initiated in a bistable and sequential manner. We furthermore show that both processes may be noise-based, which has major implications for the control of unwanted differentiation processes in pathogenic and food-spoilage micro-organisms.
了解枯草芽孢杆菌感受态发育和芽孢形成的异质（或双稳态）表达模式的基础。
通过对各种启动子 - 绿色荧光蛋白融合体进行流式细胞术分析，我们确定了在化学限定培养基（CDM）和生物膜中感受态发育和芽孢形成起始的单细胞基因表达模式。
我们表明，在CDM中感受态发育和芽孢形成起始仍以双稳态方式启动，与在复杂培养基中的情况相同，但在时间上是相继发生的。此外，我们提供了实验证据，证明感受态和芽孢形成可以在通常不会触发这些过程的条件下发生。
一些病原体能够形成自然感受态，随着这些生物体获得性多药耐药性的增加，这成为一个严重的医学问题。另一种适应性微生物反应是孢子形成。由于其耐热性和疏水性，多种物种的孢子是食品工业主要关注的对象。使用模式生物枯草芽孢杆菌，我们表明感受态发育和芽孢形成以双稳态和相继的方式启动。我们还表明这两个过程可能基于噪声，这对控制致病和食品腐败微生物中不需要的分化过程具有重要意义。
