Understanding of biological nitrogen fixation has advanced with impressive rapidity during the last decade. As befits a developing area of Science, these advances have uncovered information and raised questions which will have, and indeed have had, repercussions in numerous other branches of science and its applications. This 'information explosion', to use one of to-day's cant idioms, was initiated by the discovery, by a group of scientists working in the Central Research laboratories of Dupont de Nemours, U. S. A. , of a reproducibly active, cell-free enzyme preparation from a nitrogen fixing bacterium. Full credit is due to them. But subsequent developments, albeit sometimes quite as impressive, have too often been marked by that familiar disorder of a developing field of research-the scramble to publish. It is a scramble which, at its best, may represent a laudable desire to inform colleagues of the latest developments; yet which too easily develops into an undignified rush for priority, wherewith to impress one's Board of Directors or Grant-giving Institution. This, in miniature, is the tragedy of scientific research to-day: desire for credit causes research to be published in little bulletins, notes and preliminary communications, so that only those intimately involved in the field really know what is happening (and even they may well not see the forest for the trees). Those outside the field, or working in peripheral areas, may glean something of what is going on from reviews and fragments presented at meetings, but the broad pattern of development is often elusive.

This volume constitutes the proceedings of an international meeting held from June 28 to July 1, 1981, at Zif, Zentrum far Interdisziplin~re Forschung an der Universit~t Bielefeld, West Germany. The meeting was one of a continuing series organized through Zif on topics which transcend the boundaries of the traditional academic disciplines. The almost exponentially growing area of nitrogen fixation research fits this criterion completely. It is, however, so broad that we oriented and focused the meeting on just the chemical, biochemical, and genetic aspects to maximize the interaction among the participants and to produce a volume which would serve as a reference source for the involved researcher, the newly interested scientist and those with a more casual interest. The meeting was generously supported by Zif, the Westf~lisch Lippische Universit~tsgesellschaft, and the Fonds der Chemischen Industrie. We sincerely thank these organizations for their generosity and interest and for recognizing the importance of nitrogen fixation research for the future of mankind.

This 1976 volume provides information, presented at an international symposium in Edinburgh, on the free-living nitrogen-fixing bacteria and blue-green algae. In addition to information on the distribution of the nitrogenase enzyme within these groups, their role in the soil and in aquatic systems is considered, as are the methods of measuring nitrogen fixation.

Phylogenetic classification of nitrogen-fixing organisms. Physiology of nitrogen fixation in free-living heterotrophs. Nitrogen fixation by photosynthetic bacteria. Nitrogen fixation in cyanobacteria. Nitrogen fixation by methanogenic bacteria. Associative nitrogen-fixing bacteria. Actinorhizal symbioses. Ecology of bradyrhizobium and rhizobium. The rhizobium infection process. Physiology of nitrogen-fixing legume nodules: compartments, and functions. Hydrogen cycling in symbiotic bacteria. Evolution of nitrogen-fixing symbioses. The rhizobium symbiosis of the nonlegume parasponia. Genetic analysis of rhizobium nodulation. Nodulins in root nodule development. Plant genetics of symbiotic nitrogen fixation. Molecular genetics of bradyrhizobium symbioses. The enzymology of molybdenum-dependent nitrogen fixation. Alternative nitrogen fixation systems. Biochemical genetics of nitrogenase. Regulation of nitrogen fixation genes in free-living and symbiotic bacteria. Isolated iron-molybdenum cofactor of nitrogenase.

This volume is a wide-ranging critical evaluation by international experts of the state of knowledge in the whole field of biological nitrogen fixation. It includes coverage of the chemistry of N2 reduction, the biochemistry and molecular biology of the molybdenum and vanadium nitrogenases. There is review of the whole range of organisms fixing N2, including the free-living and symbiotic organisms (bacteria, cyanobacteria, actinomycetes). Detailed consideration is given to the ecology and agricultural use of the root nodule bacteria, the molecular biology and biochemistry of nodule formation and fuction. The practicability of extending symbiotic N2-fixation to other systems or to greater efficiency is examined.

The Present Volume Provides An Excellent Up-To-Date Account Of The Course And Development Of Biochemistry. The Text Revolves Around The Basic Principles Of Biochemistry As Well As Molecular And Biochemical Control Mechanisms Responsible For Structural, Informational And Behavioural Properties Of Cells Resulting In A Composite Picture Of Modern Biochemistry. The Book Is Organized Into Five Sections That Follows An Introductory Chapter Dealing With Biochemical Basis Of Life. Part I Treats The Foundations And Fundamentals Which Includes Four Chapters To Help Prepare A Student Finally To Enter The Realm Of Biochemistry. This Part Is Especially Designed To Clarify The Basic Concepts And Introducing Quantitation In Biochemical Sciences And Represents A Distinctive And Crucial Feature Above All The Existing Texts. Part Ii Deals With Molecular Structure And Organization Of Biomolecules. This Part Is Composed Of Five Chapters Describing In Detail, The Biochemical Organization Of Information Molecules In Living Cells. Part Iii Represents Biosynthesis Of Biomolecules Covering Five Chapters Describing In Detail The Biochemical Control Of Traffic Of Information Molecules In The Living Cells. Part Iv Describes The Dynamics Of Energy Transformation And Represents Six Chapters Dealing With The Maintenance And Expenditure Of Energy In Biochemical Processes. Part V Deals With Enzymology And Special Aspects Of Metabolism And Includes Eleven Chapters Especially Devoted To Cover Recent Developments And Topics Of Current Importance. This Volume Concludes With A Chapter Dealing With The Place And Relevance Of Biochemistry On An Interdisciplinary Platform. Every Chapter Is Followed By A Short List Of Selected General References Pertaining To That Particular Subject. There Are Seven Indices Following The Complete Write Up And Is Primarily Directed Towards Providing Additional And Extra Information Useful To Establish A Link Between All The Sections And Chapters.In View Of Academic Curriculum Existing In Various Universities And Institutions (Including Agricultural Universities), The Present Book Should Conform To The Requirements And Interests Of Honours And Postgraduate Students In Life Sciences In General Including Biochemistry, Botany, Zoology, Genetics And Microbiology.

We are witnessing an increased awareness of the earth's environment. Examples are easily seen in the rise of 'Green Parties' across Europe, North America, Australasia, and lately Eastern Europe. The public outcry following industrial mishaps in Alaska, Chernobyl, Basel, and Bhopal, as well as the renewed legislative activity, such as the Clean Air Act in the USA and the European Community directive to member nation concerning the control of release of genetically engineered organisms are further examples of the general interest in the biosphere. The 'Ozone hole', 'Greenhouse gases', and 'Genetically engineered Microorganisms' have gained public profiles, and are discussed widely in newspapers, magazines and the electronic media. A recent educational survey of nations, belonging to the Organisation for Economic Co-operation and Development (OECD) showed that school children are more literate with ecological terms (as listed above) than with 'pure' scientific terms, like 'phloem', 'mitosis', 'proton', or 'Jurasic period'. Perhaps the increase in awareness is cyclical, being fed by non-scientific, sociological and economic advances. The late 1960s/early 1970s saw a major increase in environmental consciousness. Anti-pollution groups were founded, healthfood shops and naturopathy became acceptable as did recycling, the use of lead-free gasoline, and the reduced usage of environmental toxins, like DDT and PCB. For example, Monsanto Chemical Company instigated a self-imposed halt to the manufacture of PCB in the mid-seventies. Chemical companies started to look at biodegradable herbicides, slow release fertilizers, and specifically targeted pesticides.

Biological Properties is a collection of papers that deals with the biological properties of iron-sulfur proteins. One paper reviews the role of electron paramagnetic resonance in forwarding knowledge about iron-sulfur proteins. Iron-sulfur proteins are iron proteins where sulfur is a ligand of the iron, of which the iron is not simultaneously held by a stronger ligand such as porphyrin. Another paper discusses the role of bacterial ferredoxins in coupled oxidation-reduction reactions, the role of hydrogenase in oxidation-reduction, as well as the bacterial iron-sulfur proteins, such as azoferredoxin and molybdoferredoxin. Abiological models of nitrogenase involve molybdenum and iron with sulfur ligands; these abiological systems can be the first models that show the biological activity of iron-sulfur enzymes which these systems try to copy. One paper investigates the role of iron-sulfur proteins in photosynthesis, particularly the photoreduction of ferrodoxin, the mechanism of NADPH formation, and the possible role of ferrodoxin in cyclic photophosphorylation. This collection is suitable for bio-chemists, cellular biologists, micro-biologists, and scientists involved in research in the biological disciplines.