This book is a compilation of the research which was presented during the NATO-Advanced Research Workshop (ARW) entitled "Advances in Bacterial Paracrystalline Surface Layers" held in London, Ontario, Canada during September 27 to 30, 1992. The organizing committee consisted of the two Workshop directors, S. F. Kaval and T. J. Beveridge, and H. Konig, U. B. Sleytr and T. J. Trust; their summary statements about the significance and success of the NATO-ARWare in Chapter 37 of this book. This was the third international workshop on bacterial S-layers and it demonstrated unequivocally how rapidly research is progressing. The Workshop was made possible by financial support from the North Atlantic Treaty Organization (NATO), the Medical Research Council of Canada (MRC), the Natural Seiences and Engineering Research Council of Canada (NSERC), and the Canadian Bacterial Diseases Network (CBDN) which is a Canadian National Centre of Excellence (NCE). We are very grateful for the support from all of these agencies since their financial aid made it possible to bring to London, Canada a truly international group of S-layer experts. We encouraged the attendance and participation of graduate fellows and research associates, and their presentations students, postdoctoral was an intense three constitute the "Poster" section of this book. The NATO-ARW day workshop held at a delightful secluded location (Spencer Hall) so that the delegates had both formal and informal occasions to interact and evolve new ideas.