For a long time microbial ecology has been developed as a distinct field with in Ecology. In spite of the important role of microorganisms in the environ ment, this group of 'invisible' organisms remained unaccessable to other ecologists. Detection and identification of microorganisms remain largely dependent on isolation techniques and characterisation of pure cultures. We now realise that only a minor fraction of the microbial community can be cultivated. As a result of the introduction of molecular methods, microbes can now be detected and identified at the DNA/RNA level in their natural environment. This has opened a new field in ecology: Molecular Microbial Ecology. In the present manual we aim to introduce the microbial ecologist to a selected number of current molecular techniques that are relevant in micro bial ecology. The first edition of the manual contains 33 chapters and an equal number of additional chapters will be added this year. Since the field of molecular ecology is in a continuous progress, we aim to update and extend the Manual regularly and will invite anyone to deposit their new protocols in full detail in the next edition of this Manual.

Two major problems encountered as we approach a new century are the availability of resources for chemicals and energy, and environmental pollution. This book highlights the importance of biotransformation as a solution to these problems and considers traditionally separate areas as one interdependent discipline, in terms of the underlying mechanistic biochemistry and the research techniques employed. The provision of resources has largely centred around non-renewable materials, especially oil. Diminishing reserves of these, together with uncertainties of supply and cost have stimulated great interest in renewable resources. These are largely lignocellulosic materials (e.g. wood and straw) which are available through natural biomass turnover, farming and forestry and from wastes generated by industrial processes. An excellent example is that of kraft lignin, a by-product of pulp and paper production, amounting to 60 million tonnes per annum and which is largely wasted by burning or landfilling. This aromatic polymer has enormous potential as a feedstock to the chemical industry. Environmental pollution is no longer accepted as inevitable for a technological society. Over the past decade there has been a tremendous increase in awareness of the effects of pollution and public pressure has influenced both industry and government. However, to be realistic, it is not possible to replace all processes generating polluting wastes with clean alternatives. Instead, treatments of pollution, both at source and after an incident, are alternatives in many instances and a great deal of emphasis is currently being placed on these.

This new book provides a sound summary of the rapidly expanding body of knowledge on ground water pollution sources, evaluation and control. It is used to plan and implement ground water quality management programs, and also may be used as a text. The first three (introductory) chapters are about ground water quality, its importance, its management, and information sources.

These volumes present the main classes of useful laboratory model systems used to study microbial ecosystems, with emphasis on the practical details for the use of each model. The most commonly used model, the homogeneous fermenter, is featured along with linked homogeneous culture systems, film fermenters, and percolating columns. Additionally, gel-stabilized culture systems which incorporate molecular diffusion as their main solute transfer mechanism and the microbial colony are explained. Chapters comparing model systems with "microcosms" are included, along with discussions of the value of computer models in microbial ecosystem research. Highlighted is a global discussion of the value of laboratory models in microbial ecology.