Environmental Biotechnology Lab, The University of Hong Kong, Hong Kong, SAR, China.
Anal Bioanal Chem. 2012 Sep;404(5):1465-75. doi: 10.1007/s00216-012-6225-y. Epub 2012 Jul 21.
Surface-enhanced Raman scattering (SERS) has recently been proved to be a promising technique for characterizing the chemical composition of the biofilm matrix. In the present study, to fully understand the chemical variations during biofilm formation, SERS based on silver colloidal nanoparticles was applied to evaluate the chemical components in the matrix of biofilm at different growth phases, including initial attached bacteria, colonies, and mature biofilm. Meanwhile, atomic force microscopy was also applied to study the changes of biofilm morphology. Three model bacteria, including Escherichia coli, Pseudomonas putida, and Bacillus subtilis, were used to cultivate biofilms. The results showed that the content of carbohydrates, proteins, and nucleic acids in the biofilm matrix increased significantly along with the biofilm growth of the three bacteria judging from the intensities and appearance probabilities of related marker peaks in the SERS spectra. The content of lipids, however, only increased in the Gram-negative biofilms (E. coli and P. putida) rather than the Gram-positive biofilm (B. subtilis). Our findings strongly suggest the SERS has significant potential for studying chemical variations during biofilm formation.
表面增强拉曼散射（SERS）最近被证明是一种很有前途的技术，可以用于表征生物膜基质的化学成分。在本研究中，为了充分了解生物膜形成过程中的化学变化，采用基于银胶体纳米粒子的 SERS 来评估不同生长阶段生物膜基质中的化学组成，包括初始附着细菌、菌落和成熟生物膜。同时，原子力显微镜也被用于研究生物膜形态的变化。使用三种模式细菌，包括大肠杆菌、假单胞菌和枯草芽孢杆菌，来培养生物膜。结果表明，从 SERS 光谱中相关标记峰的强度和出现概率来看，随着三种细菌生物膜的生长，生物膜基质中碳水化合物、蛋白质和核酸的含量显著增加。然而，脂质的含量仅在革兰氏阴性生物膜（大肠杆菌和假单胞菌）中增加，而在革兰氏阳性生物膜（枯草芽孢杆菌）中则没有增加。我们的研究结果强烈表明 SERS 具有研究生物膜形成过程中化学变化的巨大潜力。
