The Photosynthetic Bacteria

Anoxygenic Photosynthetic Bacteria is a comprehensive volume describing all aspects of non-oxygen-evolving photosynthetic bacteria. The 62 chapters are organized into themes of: Taxonomy, physiology and ecology; Molecular structure of pigments and cofactors; Membrane and cell wall structure: Antenna structure and function; Reaction center structure and electron/proton pathways; Cyclic electron transfer; Metabolic processes; Genetics; Regulation of gene expression, and applications. The chapters have all been written by leading experts and present in detail the current understanding of these versatile microorganisms. The book is intended for use by advanced undergraduate and graduate students and senior researchers in the areas of microbiology, genetics, biochemistry, biophysics and biotechnology.

As the largest scale chemical reaction, photosynthesis supplies all of the organic carbon and oxygen for life on Earth. It is estimated that the photosynthetic activity of microorganisms is responsible for more than 50% of the primary production of molecular oxygen on Earth. This book highlights recent breakthroughs in the multidisciplinary areas of microbial photosynthesis, presenting the latest developments in various areas of microbial photosynthesis research, from bacteria to eukaryotic algae, and from theoretical biology to structural biology and biophysics. Furthermore, the book discusses advances in photosynthetic chassis, such as in the context of metabolic engineering and green chemical production. Featuring contributions by leading authorities in photosynthesis research, the book is a valuable resource for graduate students and researchers in the field, especially those studying biological evolution and the origin of life.

Results of this third Feldafing Meeting can be considered as the harvest of novel techniques in spectroscopy, biochemistry and molecular biology to the bacterial photosynthetic reaction center. New information pertains to the crystallographic and electronic structure as well as to the dynamics of primary events and the role of the protein. The answer to one long-standing problem, the mechanism of primary charge separation, converges towards a sequential scheme, supported by femtosecond spectroscopy on reaction centers with selectively modified energetics.

Here is a comprehensive survey of all aspects of these fascinating bacteria, metabolically the most versatile organisms on Earth. It compiles 48 chapters written by leading experts, who highlight the huge progress made in studies of these bacteria since 1995.

This volume contains the contributions from the speakers at the NATO Advanced Research Workshop on "Structure of the Photosynthetic Bacterial Reaction Center X-ray Crystallography and Optical Spectroscopy with Polarized Light" which was held at the "Maison d'Hotes" of the Centre d'Etudes Nucleaires de Cadarache in the South of France, 20-25 September, 1987. This meeting continued in the spirit of a previous workshop which took place in Feldafing (FRG), March 1985. Photosynthetic reaction centers are intrinsic membrane proteins which, by performing a photoinduced transmembrane charge separation, are responsible for the conversion and storage of solar energy. Since the pioneering work of Reed and Clayton (1968) on the isolation of the reaction center from photosynthetic bacteria, optical spectroscopy with polarized light has been one of the main tools used to investigate the geometrical arrangement of the various chromophores in these systems. The recent elucidation by X-ray crystallography of the structure of several bacterial reaction centers, a breakthrough initiated by Michel and Deisenhofer, has provided us with the atomic coordinates of the pigments and some details about their interactions with neighboring aminoacid residues. This essential step has given a large impetus both to experimentalists and to theoreticians who are now attempting to relate the X-ray structural model to the optical properties of the reaction center and ultimately to its primary biological function.

The photosynthetic microbes including microalgae and cyanobacteria are the most widespread photosynthetic organisms on Earth. These organisms thrive successfully in a wide range of ecological habitats, ranging from marine and freshwater to terrestrial environments. The short generation time and capability to fix the atmospheric N2 and cosmopolitan distribution make these organisms unique. Photosynthetic microbes such as cyanobacteria are used as biofertilizer for rice paddy and their application improves soil physico-chemical characteristics and the mineral nutrient status of the soil. However, in recent times they have been exploited for the production of several fine chemicals and biofuel. Due to their simple cellular organization, the bare minimum requirement of nutrients and ease of cultivation, recently the microalgae have been exploited and accompanied by the capacity to produce bio-energy, especially bio-diesel. Use of photosynthetic microbes in wastewater treatment has also generated considerable interest in the scientific community and industry at large. Bioremediation using photosynthetic microbes is an emerging area of research and the organisms accumulate or degrade several environmental contaminants and heavy metals. Because of the antagonistic properties, they are also a potential source of various bioactive compounds. In brief, the potential of photosynthetic microbes could be harnessed for economic viability and sustainability of agro-ecosystems. This book attempts to highlight the potential and prospects of the photosynthetic microbes for the welfare of mankind in view of the anticipated population explosion and global climate change.