Rapid and direct analysis of small molecular weight extra polysaccharides of Bacteria by Hi-Speed centrifugation coupled with nanoparticle-assisted laser desorption/ionization (HC-Np-ALDI-MS) mass spectrometry

Gangaraju Gedda, Judy Gopal and Hui-Fen Wu

: Agrotechnol

Abstract:

The analysis of extracellular polymeric substances (EPS) from bacteria traditional methods requires chemical treatments and complicated separation procedures. Analysis of Low molecular weight compounds on Convention MALDI-MS is very difficult due to conventional organic matrixes like DHB or CHCA matrix background peaks are interfere with samples peaks at low molecular range .For avoiding those problems we developed a method, combining Hi-Speed centrifugation or physical extraction method with Nano-particle assisted laser desorption/ionization (HC-Np-ALDI-MS) mass spectrometry (MS) without any chemical treatment or extraction methods, separation and purification of EPS. The objective of this study is to demonstrate the use of Hi-Speed centrifugation coupled with Nanoparticle-assisted laser desorption/ionization (NALDI) mass spectrometry (MS) as a powerful technique for rapid, simple and direct analysis of low molecular weight EPS secreted by bacteria. For this we prepared manganese oxide nanoparticles and developed a nano-PALDI MS method to analyze EPS extract from different bacteria?s by using Hi-Speed centrifugation. Our studies showed that nano-PALDI MS was selective for analysis of low molecular weight EPS. This study is a preliminary study reporting for the first time the feasibility of nano-PALDI MS techniques for the analysis of bacterial EPS without prior complicated purification and separation methodologies. The MnO 2 Nano-particles working as matrix during MALDI-MS analysis and help to ionize the EPS Samples. The mass spectra did not show any background interference in the low-m/z range. The results reporting the successful use of the manganese dioxide particles as matrices for analysis of bacterial EPS has been outlined

Biography :

Gangaraju Gedda has a Masters in Analytical chemistry from JNTUH, India. He is currently a Ph.D student in Marine Biotechnology at National Sun- Yat Sen University, Taiwan. He has published articles on the use of electrospray ionization (ESI) and on the use of matrix-assisted laser desorption/ ionization (MALDI) for mass-spectrometry-based measurement of the molecular weights of EPS molecules within bacteria. His current research focuses on synthesizing nanomaterials, including nanowires and Nano wire based bio-chip, for use as bio-chip-based Mass Sensors. He is using these sensors to analyze pathogenic bacteria, to perform matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF- MS).