The global regulatory hns gene negatively affects adhesion to solid surfaces by anaerobically grown Escherichia coli by modulating expression of flagellar genes and lipopolysaccharide production
The global regulatory hns gene negatively affects adhesion to solid surfaces by anaerobically grown Escherichia coli by modulating expression of flagellar genes and lipopolysaccharide production
复制标题
DOI：
10.1128/jb.184.6.1522-1529.2002
复制
发表时间：
2002-03-01
影响因子：
3.2
通讯作者：
Zehnder, AJB
中科院分区：
文献类型：
--
作者：
Landini, P;Zehnder, AJB
细菌细胞与固体表面的初始结合是生物膜形成的关键和必要步骤。在这份报告中，我们表明，大肠杆菌W3100（K-12菌株）的静止期培养物可以有效地附着在砂柱时，他们在Luria肉汤培养基中生长在28 degreesC在完全有氧条件下。相比之下，在氧限制条件下的生长导致对亲水性基材的粘附力急剧下降。我们表明，在限氧条件下，脂多糖（LPS）和鞭毛的产生以及编码主要鞭毛亚基的fliC基因的转录都会增加。全局调节基因的失活抵消了缺氧引起的LPS和鞭毛产生的增加，并允许E。大肠杆菌W3100即使在限氧条件下生长，也不能附着在砂柱上。我们认为，FliC蛋白和LPS在氧限制反应中的增加导致E. coliW 3100中表达的蛋白质。事实上，即使W3100在完全有氧条件下生长，fliC基因的过表达也会导致对沙子的粘附力降低。我们的观察结果强烈提示缺氧是一个不利的环境信号粘附在大肠杆菌。杆菌
The initial binding of bacterial cells to a solid surface is a critical and essential step in biofilm formation. In this report we show that stationary-phase cultures of Escherichia coli W3100 (a K-12 strain) can efficiently attach to sand columns when they are grown in Luria broth medium at 28 degreesC in fully aerobic conditions. In contrast, growth in oxygen-limited conditions results in a sharp decrease in adhesion to hydrophilic substrates. We show that the production of lipopolysaccharide (LPS) and of flagella, as well as the transcription of the fliC gene, encoding the major flagellar subunit, increases under oxygen-limited conditions. Inactivation of the global regulatory has gene counteracts increased production of LPS and flagella in response to anoxia and allows E. coli W3100 to attach to sand columns even when it is grown under oxygen-limited conditions. We propose that increased production of the FliC protein and of LPS in response to oxygen limitation results in the loss of the ability of E. coli W3100 to adhere to hydrophilic surfaces. Indeed, overexpression of the fliC gene results in a decreased adhesion to sand even when W3100 is grown in fully aerobic conditions. Our observations strongly suggest that anoxia is a negative environmental signal for adhesion in E. coli.