This Research Topic is the second volume of the 'Community series-Extremophiles: Microbial Genomics and Taxogenomics'. Please see the first volume here. Extreme habitats exist across the globe and span over three quarters of our planet. They can be widely different from a physical-chemical perspective as they include diverse types of extreme, such as temperature, pH, salinity, radiation, pressure, low water activity, low nutrient availability, etc. Organisms capable of adjusting, surviving, or thriving in those habitats, which are so hostile that they were previously thought to be adverse or lethal for life, are called “extremophiles”.

The great diversity of microbial life is the remaining major reservoir of unknown biological diversity on earth. To understand this vast, but largely unperceived diversity with its untapped genetic, enzymatic and industrial potential, microbial systematics is undergoing a revolutionary change in its approach to describe novel taxa based on genomic/envirogenomic information. The characterization of an organism is no longer bounded by methodological barriers, and it is now possible to fully sequence the whole genome of a strain to study individual genes, or to examine the genetic information by using different techniques. In fact, application of genomics is helping not only to provide a better understanding of the boundaries of genera and higher levels of classification, but also to refine our definition of the species concept. In addition, increased understanding of phylogeny is allowing to predict the genetic potential of microorganisms for biotechnological applications and adaptation to environmental changes. The present Research Topic on “Microbial Taxonomy, Phylogeny and Biodiversity” compiles a collection of papers covering the use of genomic sequence data in microbial taxonomy and systematics, including evolutionary relatedness of microorganisms; application of comparative genomics in systematic studies; or metagenomic approaches for biodiversity studies. We hope that this eBook incentives and encourages researchers for future discussions on microbial taxonomy and phylogenetics.

Various groups of microorganisms - bacteria, archaea, algae and even fungi - have adapted to a life in a hypersaline environment. Halophilic Microorganisms explores the many-fold aspects of life under these extreme conditions. Several contributions analyze the microbial communities in different hypersaline environments such as salterns, soda lakes, and the Dead Sea or salt sediments. Reviews of their biodiversity, phylogeny, and genetics are given as well as of the diverse adaptation strategies of salt-tolerant or salt-requiring microorganisms. Microorganisms that have adapted to moderate salt concentrations or to habitats with drastic fluctuations are also treated in addition to the extreme halophiles. Their physiological, biochemical and molecular mechanisms developed in response to salinity and high osmotic pressure as well as current and future biotechnological applications are presented.

This informative and up-to-date book is an invaluable review on current research in astrobiology and is an essential acquisition for anyone involved in this cross-disciplinary field.

Volume 41 of Methods in Microbiology is a methods book designed to highlight procedures that will revitalize the purposes and practices of prokaryotic systematics. This volume will notably show that genomics and computational biology are pivotal to the new direction of travel and will emphasise that new developments need to be built upon historical good practices, notably the continued use of the nomenclatural type concept and the requirement to deposit type strains in at least two service culture collections in different countries.

Modern approaches to microbial classification and identification, particularly those based on nucleic acid analysis, have raised the awareness and interest of microbiologists in systematics during the past decade. The extended scope of the subject has revolutionized microbial ecology with the demonstration of uncultivable microorganisms as a major component of the biosphere and evolution, with the ribosomal RNA phylogenetic tree as the basis of current classifications. However, advances in microbial systematics have also had enormous impact on other, diverse aspects of microbiology such as animal pathogenicity, plant-microbe interactions and relationships with food. In this book, we survey and discuss in depth the contribution of modern taxonomic approaches to our understanding of the microbiology of these various systems. The book does not concentrate on methods - these have been well reported elsewhere - instead it provides a unique insight into the application and value of modern systematics in diverse branches of microbiology. It will be of value to microbiologists at both research and technical levels who need to appreciate the range of organisms with which they work and the diversity within them. It will also be of value to teachers and students of microbiology courses who want to understand how systematics can enhance microbiology beyond the routine of classification, nomenclature, and identification.

The existence of life at high temperatures is quiet fascinating. At elevated temperatures, only microorganisms are capable of growth and survival. Many thermophilic microbial genera have been isolated from man-made (washing machines, factory effluents, waste streams and acid mine effluents) and natural (volcanic areas, geothermal areas, terrestrial hot springs, submarine hydrothermal vents, geothermally heated oil reserves and oil wells, sun-heated litter and soils/sediments) thermal habitats throughout the world. Both culture-dependent and culture-independent approaches have been employed for understanding the diversity of microbes in hot environments. Interest in their diversity, ecology, and physiology has increased enormously during the past few decades as indicated by the deliberations in international conferences on extremophiles and thermophiles held every alternate year and papers published in journals such as Extremophiles. Thermophilic moulds and bacteria have been extensively studied in plant biomass bioconversion processes as sources of industrial enzymes and as gene donors. In the development of third generation biofuels such as bioethanol, thermophilic fungal and bacterial enzymes are of particular interest. The book is aimed at bringing together scattered up-to-date information on various aspects of thermophiles such as the diversity of thermophiles and viruses of thermophiles, their potential roles in pollution control and bioremediation, and composting.

The printed and only official version of the Code has been published as International Code of Botanical Nomenclature (Tokyo Code). Regnum Vegetabile 131. Koeltz Scientific Books, Königstein. ISBN 3-87429-367-X or 1-878762-66-4 or 80-901699-1-0

Fungi and microbes have predominant influence in our lives. They are directly or indirectly involved in generating the food we eat and drink, besides providing life saving pharmaceutical products, including the sources of enzymes. They play a vital role in recycling of organic matter and several ecological processes. Both fungi and microbes have contributed several billion dollars worth of technological products. For instance: yeast is used in brewing and bakery, Lactobacillus ferments milk to yoghurt and a number of edible mushrooms are rich in nutrients besides possessing many medicinal properties. Bacteria and fungi serve as key organisms in understanding life processes, genetic engineering and as experimental organisms. Therefore, it is necessary to study the biology and biotechnology of these organisms. It is a humble attempt of the authors to make the readers understand the biology and biotechnology of fungi and microbes in a simpler way and also to communicate the recent developments.