Advances in Microbial Ecology was established by the International Committee on Microbial Ecology (ICOME) to provide a vehicle for in-depth, critical, and even provocative reviews to emphasize recent trends in the important field of microbial ecology. Advances in Microbial Ecology is now recognized as a major source of infor mation and inspiration both for practicing and for prospective microbial ecologists. Most reviews appearing in Advances have been prepared by leaders in particular areas follow ing invitations issued by the Editorial Board. Individuals are encouraged, however, to submit outlines of unsolicited contributions to any member of the Editorial Board for consideration for publication in Advances. With the publication of Volume 12 of Advances in Microbial Ecology there will be a change of Editor and the entire Editorial Board. The current Editor wishes to take this opportunity to thank the present Editorial Board, Ron Atlas, Bo Barker J~rgensen, and Gwyn Jones, as well as past members of the Board, for their assistance and encourage ment over the years. The new Editor of Advances in Microbial Ecology will be Gwyn Jones, with Bernhard Schink, Warwick F. Vincent, and David M. Ward as members of the Editorial Board. The outgoing Board wish the new Board every success in continu ing the traditions established by Martin Alexander, the founding Editor of Advances in Microbial Ecology. The topics featured in Volume 12 of Advances include some related to the meta bolic activities of bacteria; namely, bioremediation of oil spills, by R. M. Atlas and R.

This volume of Advances in Microbial Ecology marks a change in the editor ship of the series. The Editorial Board wishes to take this opportunity to express its gratitude to Martin Alexander, the founding editor and editor of the first five volumes, for his enterprise in establishing the series and in ensuring that Advances has become an outstanding focal point for the identification of new developments in the rapidly expanding field of microbial ecology. With the publication of this volume, we welcome Howard Slater to the Editorial Board. The policies of the Editorial Board remain the same as before. Most con tributions to Advances in Microbial Ecology will be solicited by the Board. However, individuals are encouraged to submit outlines of unsolicited contri butions to the Board for consideration for inclusion in the series. Advances is designed to serve an international audience and to provide critical reviews on basic and applied aspects of microbial ecology. Contributions in the present volume are predominantly concerned with the ecology of aquatic microorganisms, but encompass a variety of approaches to this area. The exception is the chapter by J. W. Doran on the role of micro organisms in the cycling of selenium. G-Y. Rhee discusses the effects of envi ronmental factors on phytoplankton growth. The factors limiting the produc tivity of freshwater microbial ecosystems are considered by H. W. Paerl."

usage of the terms substrate and substratum. A substrate (pI.: substrates) is a material utilized by microorganisms, generally as a source of energy. A substratum (pI.: substrata) is asolid surface to which a microorganism mayattach. REFERENCES (1) Marshall, K.C. 1976. Interfaces in Microbial Ecology. Cambridge, MA: Harvard University Press. (2) ZoBell, C.E. 1943. The effect of solid surfaces upon bacterial activity. J. Bacteriol. 46: 39-56. Standing, left to right: Paul Rutter, Rolf Freter, Mike Silverman, lan Robb, Hinrich Mrozek, Frank Dazzo, David Gingell Seated, left to right: Garth Jones, Stanislawa Tylewska, Staffan Kjelleberg, Ellen Rades-Rohkohl, Kevin Marshall Microbial Adhesion and Aggregation, ed. K.C. Marshall, pp. 5-19. Dahlem Konferenzen 1984. Berlin, Heidelberg, New York, Tokyo: Springer-Verlag. Mechanisms of Adhesion Group Report P.R. Rutter, Rapporteur F.B. Dazzo H. Mrozek R. Freter E. Rades-Rohkohl D. GingeIl I.D. Robb G.W. Jones M. Silverman 8. Kjelleberg 8. Tylewska K.C. Marshall INTRODUCTION The subject, Mechanisms of Microbial Attachment, has proved to be a fertile sour ce of argument between both microbiologists and physical chemists. In order to find common ground for discussion, the group endeavored to come to a consensus regarding a number of definitions pertinent to the subject. Some of these are described in the text and others will be found at the end of this report.