Identification of membrane proteins is the main focus of the present study. Preparation, separation and identification of membrane proteins remain a highly challenging and interesting task. In proteomics, proteins are usually identified using mass spectrometry and identify proteins by comparing with existing protein or genome databases. This book deals with the twin objectives of efficient membrane protein preparation in general, as well as identification of proteins from species of unknown genome sequences, using an Antarctic bacterium Pseudomonas syringae, as a model system. Using a combination of de novo sequencing and chemical modification of tryptic peptides followed by mass spectrometry, the peptide sequence was determined/validated.It is hoped that the procedures developed and applied in this study would be useful to a large number of researchers working in diverse areas of Microbiology, Chemistry, Biochemistry,Biotechnology, Bioinformatics, Proteomics and Mass spectrometry.