Communities of bacteria called biofilms are characterized by reduced diffusion, steep oxygen, and redox gradients and specific properties compared to individualized planktonic bacteria. In this study, we investigated whether signaling via nitrosylation of protein cysteine thiols (S-nitrosylation), regulating a wide range of functions in eukaryotes, could also specifically occur in biofilms and contribute to bacterial adaptation to this widespread lifestyle. We used a redox proteomic approach to compare cysteine S-nitrosylation in aerobic and anaerobic biofilm and planktonic Escherichia coli cultures and we identified proteins with biofilm-specific S-nitrosylation status. Using bacterial genetics and various phenotypic screens, we showed that impairing S-nitrosylation in proteins involved in redox homeostasis and amino acid synthesis such as OxyR, KatG, and GltD altered important biofilm properties, including motility, biofilm maturation, or resistance to oxidative stress. Our study therefore revealed that S-nitrosylation constitutes a physiological basis underlying functions critical for E. coli adaptation to the biofilm environment.

与个体化的浮游细菌相比，称为生物膜的细菌群落的特点是扩散减少、氧气陡峭、氧化还原梯度和特定特性。在这项研究中，我们研究了通过蛋白质半胱氨酸硫醇的亚硝基化（S-亚硝基化）信号传导，调节真核生物的广泛功能，是否也可以特异性地发生在生物膜中，并有助于细菌适应这种广泛的生活方式。我们使用氧化还原蛋白质组学方法来比较好氧和厌氧生物膜和浮游大肠杆菌培养物中的半胱氨酸S-亚硝基化，我们鉴定了具有生物膜特异性S-亚硝基化状态。使用细菌遗传学和各种表型筛选中，我们发现损害小号在涉及氧化还原平衡和蛋白质-nitrosylation氨基酸合成如OxyR，katG基因，和GltD改变重要生物膜的性质，包括蠕动，生物膜成熟或氧化胁迫抗性。因此，我们的研究表明，S-亚硝基化构成了大肠杆菌适应生物膜环境的关键功能的生理基础。