Microbial Diversity: Form and Function in Prokaryotes. Oladele Ogunseitan. Blackwell Publishing, Malden, MA, 2005. 292 pp., illus. $84.95 (ISBN 0632047089 paper).
In the introduction to Microbial Diversity, Oladele Ogunseitan states that his purpose is to eliminate the gap between “the appreciation of [the diversity in] large animal and plant organisms (macrobiodiversity) and the widely acknowledged ignorance of the diversity of microorganisms (…microbiodiversity).” His book goes a long way toward achieving this goal.
Ogunseitan is a professor of environmental health, science, and policy at the University of California, Irvine (UCI). He received his PhD from the University of Tennessee, Knoxville, in 1988 and joined the faculty at UCI shortly thereafter; he has published extensively on molecular microbial ecology and the use of proteomics and genomics in assessing the genetic and physiological richness of environmental microbial communities. Among other honors, Ogunseitan has been a Global Environmental Assessment Faculty Fellow at Harvard University and a UNESCO–ASM visiting resource fellow. These experiences have provided him with the time and expertise to write an excellent book on microbial diversity.
The work is divided into two major sections. The first consists of five chapters that discuss concepts and methods used to define and study microbiodiversity. Both culture-based and molecular methods are explained in detail. The descriptions and excellent illustrations allow the reader to understand how to carry out the techniques and how to apply them to the study of microbial diversity. Debate over the idea of a “bacterial species” is presented in the first chapter of the book. This discussion is perhaps the author's most important contribution to the reader's understanding of microbiodiversity. As scientists learn more about the microbial world, it becomes more, rather than less, difficult to define a bacterial species. Ogunseitan begins his explanation with a discussion of the traditional concepts of species that have often been applied to plants and animals. He then points out the pros and cons of each of these hypotheses and how well each may be applied to developing a concept of species for prokaryotes. His arguments are laid out in a thoughtful and informative manner that presents the many sides of this difficult question, whose answer influences scientists' ideas of both microbial diversity and evolution. He ends his first chapter with a discussion of the emerging concepts of bacterial taxonomy and systematics and how these concepts apply to the study of microbial ecology.
The second section, composed of six chapters, relates how the techniques and concepts presented in the preceding section have been used to broaden our understanding of microbial diversity. Ogunseitan begins with a chapter devoted to a discussion of microbial evolution. Several chapters that follow explain the cycling of biologically important chemical elements and compounds and how the roles of environmental microorganisms in these processes have led to microbial diversification.
Additional chapters deal with the interactions among microorganisms and between microorganisms and macroorganisms in the environment. Each of these interactions is discussed in the context of how it has affected microbial evolution and diversity and how, in turn, microbes have influenced the development of their environments. The book ends with a chapter entitled “Microbial Diversity and Global Environmental Issues.” This excellent summary chapter introduces current environmental issues such as pollution, climate change, and preservation biology. It discusses the use of microbial diversity as an index of environmental changes and the role of microorganisms in providing solutions to these problems. This chapter clearly stresses the urgency of these issues for the 21st century.
The work is intended for use as a textbook. Several special features facilitate this use: extensive illustrations (including four-color plates), text and image boxes, questions for study at the end of each chapter, lists of suggested readings for each chapter, a CD-ROM to facilitate classroom presentations, and a dedicated Web site. Particularly successful are the outstanding text and image boxes, many devoted to historically important events in the development of molecular microbial ecology. Such insights are important to help students develop an understanding of the flavor as well as the facts of this discipline. The Web site contains resources for instructors, including suggestions for presentation of the material in each chapter and a sample class syllabus. Student resources include animations, interactive exercises, and links to related Web sites.
The “questions for further investigation” found at the end of each chapter are indeed thought-provoking, and many require a significant amount of research to develop a proper answer. Instructors may want to use them as assignments or as subjects for classroom discussion. The book includes an appendix of fully sequenced microbial genomes, a glossary of terms, and an index. Unfortunately, the index is minimal and the glossary incomplete, with subject-specific terms missing or inadequately defined. I hope that a second edition will remedy the problem by expanding the index and glossary.
Although the instructional resources make for a useful text, determining the level for which it is most suited is problematic. The author suggests its use in one or more of the courses that the American Society for Microbiology recommends as the core of an undergraduate curriculum in microbiology (introduction to microbiology, microbial physiology, microbial genetics, and microbial diversity). I gave the book to colleagues in my department who teach each of these classes. As a group, they agreed that its place in this curriculum should be as a reference or supplemental text for the brightest and most involved students. The level is probably too high for the average undergraduate, and the subject is too specific for use as a general text in any of these courses. It is probably better suited to a graduate course in microbial diversity or microbial evolution.
Despite its limitations as an introductory textbook, this work is an excellent introduction to microbial diversity for readers with a serious interest in the subject. It is extremely well written and rigorous in its presentation and attention to detail. Although the technical subjects it addresses are often difficult, the text is never abstruse. The facts are well documented, and the book contains an extensive reference list of primary sources (in addition to the suggested readings at the end of each chapter). Microbial Diversity is a good read, and a thorough introduction to a complex topic.