X-ray photoelectron spectroscopy for the study of microbial cell surfaces

X-ray photoelectron spectroscopy (XPS) is well known for the characterisati on of material surfaces, but at first glance, is an unexpected technique to study the composition of microbial cell surfaces. Despite the fact that in timate contact between materials and microbial cell surfaces occurs in many situations, such as on oil-platforms, in water pipelines and bioreactors o r on biomedical implants, XPS studies on the composition of microbial cell surfaces are less known, but equally relevant. In this review, microbial sa mple preparations are discussed, as well as relationships between microbial compositions using XPS. Biochemical and physical properties, such as micro bial cell surface charge and hydrophobicity are also discussed. A reference guide, giving the overall cell surface composition of 210 strains determin ed by XPS, as collected from the literature is given. Hierarchical cluster analysis on these data reveals interesting new insights on staphylococcal c ell surfaces, as well as a distinction between staphylococci, yeasts and ot her microorganisms. It is concluded that XPS on microbial cell surfaces yie lds useful information, complementing other biochemical and physical cell s urface characterisations. (C) 2000 Elsevier Science B.V. All rights reserve d.