Advances In Biology And Ecology Of Nitrogen Fixation

Biological nitrogen fixation has essential role in N cycle in global ecosystem. Several types of nitrogen fixing bacteria are recognized: the free-living bacteria in soil or water; symbiotic bacteria making root nodules in legumes or non-legumes; associative nitrogen fixing bacteria that resides outside the plant roots and provides fixed nitrogen to the plants; endophytic nitrogen fixing bacteria living in the roots, stems and leaves of plants. In this book there are 11 chapters related to biological nitrogen fixation, regulation of legume-rhizobium symbiosis, and agriculture and ecology of biological nitrogen fixation, including new models for autoregulation of nodulation in legumes, endophytic nitrogen fixation in sugarcane or forest trees, etc. Hopefully, this book will contribute to biological, ecological, and agricultural sciences.

This book provides an introductory-level survey of biological nitrogen fixation, covering the role of the process in the global nitrogen cycle as well as its biochemistry, physiology, genetics, ecology, general biology and prospects for its future exploitation.

Biological nitrogen fixation has essential role in N cycle in global ecosystem. Several types of nitrogen fixing bacteria are recognized: the free-living bacteria in soil or water; symbiotic bacteria making root nodules in legumes or non-legumes; associative nitrogen fixing bacteria that resides outside the plant roots and provides fixed nitrogen to the plants; endophytic nitrogen fixing bacteria living in the roots, stems and leaves of plants. In this book there are 11 chapters related to biological nitrogen fixation, regulation of legume-rhizobium symbiosis, and agriculture and ecology of biological nitrogen fixation, including new models for autoregulation of nodulation in legumes, endophytic nitrogen fixation in sugarcane or forest trees, etc. Hopefully, this book will contribute to biological, ecological, and agricultural sciences.

This volume discusses the most recent advances in biological nitrogen fixation, with chapters written by experts on the ecology, physiology, biochemistry and genetics of biological nitrogen fixation.

The process of converting atmospheric nitrogen into ammonia and other nitrogenous compounds in soil is termed as nitrogen fixation. Most of the biological nitrogen is fixed by prokaryotic bacteria. A few of these are cyanobacteria, azotobacter, azospirillum, rhizobium and bradyrhizobium. Clover, soybean, peanut, etc., are some of the plants which help in nitrogen fixation process. These processes are part of the nitrogen cycle. They are of utmost significance in agriculture as nitrogen is required for the synthesis of various organic compounds like amino acids, nucleic acids and proteins. Nitrogen is also fixed by natural phenomenon such as lightning. It is also responsible for the formation of nitrogen oxides which may react with water to form nitrous acid or nitric acid. The acids seep into the soil where they are converted into nitrates. This book includes some of the vital pieces of work being conducted across the world, on various topics related to nitrogen fixation. From theories to research to practical applications, case studies related to all contemporary topics of relevance to this field have been included in it. This book is a vital tool for all researching or studying the biological and ecological aspects of nitrogen fixation as it gives incredible insights into emerging trends and concepts.

Poverty is a severe problem in Africa, Asia, South America and even in pockets of the developed world. Addressing poverty alleviation via the expanded use of biological nitrogen fixation in agriculture was the theme of the 15th International Congress on Nitrogen Fixation. Because nitrogen-fixation research is multidisciplinary, exploiting its benefits for agriculture and environmental protection has continued to attract research by diverse groups of scientists, including chemists, biochemists, plant physiologists, evolutionary biologists, ecologists, agricultural scientists, extension agents, and inoculant producers. The 15th International Congress on Nitrogen Fixation was held jointly with the 12th International Conference of the African Association for Biological Nitrogen Fixation. This joint Congress was hosted in South Africa at the Cape Town International Conv- tion Centre, 21–26 January 2007, and was attended by about 200 registered participants from 41 countries world-wide. During the Congress, some 100 oral and approximately 80 poster papers were presented. The wide range of topics covered and the theme of the Congress justifies this book’s title, Nitrogen Fixation: Applications to Poverty Alleviation.

The 14th International Nitrogen Fixation Congress was held in Beijing, China from October 27th through November 1st, 2004. This volume constitutes the proceedings of the Congress and represents a compilation of the presentations by scientists from more than 30 countries around the World who came to Beijing to discuss the progress made since the last Congress and to exchange ideas and information. This year marked the 30th anniversary of the first Congress held in Pullman, Washington, USA, in 1974. Since then, this series of Congresses has met five times in North America (three in the United States and once each in Canada and Mexico), once in South America (Brazil), four times in Western Europe (once each in Spain, The Netherlands, Germany and France), once in Eastern Europe (Russia), and once in Australia; and now for the first time in Asia. China was a most appropriate choice because China is a big country with the largest population in the World, about 1. 3 billion people, which is about 22% of the World’s population. It is traditionally an agricultural country, even though China has only 7% of the available farming land. This situation explains why agriculture and its productivity are major issues for the Chinese people, its government and the scientists in the field.

In order to understand a process as complex as nitrogen fixation and to be in a position to manipulate it for the benefit of mankind, researchers are now working at the frontiers of science in many different areas: protein structure and function; catalytic mechanisms; electron transfer processes; regulatory circuits and environmental sensing; metabolic integration; chemical communication between organisms; differentiation; genome structure and function; microbial ecology; plant physiology; plant molecular biology; and agronomy. This volume represents a testimony to the advances in nitrogen fixation research that have been made and the contribution of these efforts to the solution of many other varied scientific problems. Limiting steps for future advances are analyzed and new horizons in nitrogen fixation research are proposed.