Mitochondria are sometimes called the powerhouses of eukaryotic cells, because mitochondria are the site of ATP synthesis in the cell. ATP is the universal energy currency, it provides the power that runs all other life processes. Humans need oxygen to survive because of ATP synthesis in mitochondria. The sugars from our diet are converted to carbon dioxide in mitochondria in a process that requires oxygen. Just like a fire needs oxygen to burn, our mitochondria need oxygen to make ATP. From textbooks and popular literature one can easily get the impression that all mitochondria require oxygen. But that is not the case. There are many groups of organismsm known that make ATP in mitochondria without the help of oxygen. They have preserved biochemical relicts from the early evolution of eukaryotic cells, which took place during times in Earth history when there was hardly any oxygen avaiable, certainly not enough to breathe. How the anaerobic forms of mitochondria work, in which organisms they occur, and how the eukaryotic anaerobes that possess them fit into the larger picture of rising atmospheric oxygen during Earth history are the topic of this book.

"Hydrogenosomes and Mitosomes: Mitochondria of Anaerobic Eukaryotes" provides a summary of the current knowledge of these organelles which occur in unicellular, often parasitic organisms, including human pathogens. These organelles exhibit a variety of structures and functions. This work describes properties such as protein import, structure, metabolism, adaptation, proteome and their role in drug activation and resistance. Further topics include organelle evolution and biogenesis.

The evolutionary origins of hydrogenosomes have been the subject of considerable debate. This volume closes the gap between the endosymbiotic theory for the origin of organelles and their incorporation into evolutionary theory. It reveals that identifying the genetic contribution to eukaryotes of the mitochondrial endosymbiosis, and revealing the functions of its descendent organelles, are key to understanding eukaryotic biology and evolution.

In this book internationally acclaimed researchers critically review the most important aspects of research on anaerobic parasitic protozoa, providing the first coherent picture of their genomics and molecular biology since the publication of the genomes. Chapters are written from a molecular and genomic perspective and contain speculative models upon which future research efforts can be based. Topics include: the genomes of Entamoeba histolytica, Trichomonas vaginalis, Giardia and other diplomonads; the cytoskeletons of Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis; genomic.

Multiple demographic or economic parameters contribute to the origin of emerging infections, for example: poverty, urbanization, climate change, conflicts and population migrations. All these factors are a challenge to assess the impact (present and future) of parasitic diseases on public health. The intestine is a major target of these infections; it is a nutrient-rich environment harbouring a complex and dynamic population of 100 trillion microbes: the microbiome. Most researches on the microbiome focus on bacteria, which share the gut ecosystem with a population of uni- and multi cellular eukaryotic organisms that may prey on them. Our interest focuses on the families of eukaryotic microbes inhabiting the intestine, called “intestinal eukaryome”, that include fungi, protists and helminths. Knowledge on the reciprocal influence between the microbiome and the eukaryome, and on their combined impact on homeostasis and intestinal diseases is scanty and can be considered as an important emerging field. Furthermore, the factors that differentiate pathogenic eukaryotes from commensals are still unknown. This book presents an overview of the science presented and discussed in the First Eukaryome Congress held from October 16th to 18th, 2019 at the Pasteur Institute in Paris. This book covers the following topics: Phylogenetic, prevalence, and diversity of intestinal eukaryotic microbes; and their (still enigmatic) historical evolution and potential contributions to mucosal immune homeostasis. Integrative biology to study the molecular cell biology of parasite-host interactions and the multiple parameters underlining the infectious process. The exploitation of tissue engineering and microfluidics to establish three-dimensional (3D) systems that help to understand homeostasis and pathological processes in the human intestine.

Interactions with the oxic world are explored in the last chapter. The ecological and evolutionary significance of the arrival of oxygen in the Proterozoic is discussed in detail, especially as it eventually led to the possibility of long food chains.

Microbial ecology is the study of interactions among microbes in natural environments and their roles in biogeochemical cycles, food web dynamics, and the evolution of life. Microbes are the most numerous organisms in the biosphere and mediate many critical reactions in elemental cycles and biogeochemical reactions. Because microbes are essential players in the carbon cycle and related processes, microbial ecology is a vital science for understanding the role of the biosphere in global warming and the response of natural ecosystems to climate change. This novel textbook discusses the major processes carried out by viruses, bacteria, fungi, protozoa and other protists - the microbes - in freshwater, marine, and terrestrial ecosystems. It focuses on biogeochemical processes, starting with primary production and the initial fixation of carbon into cellular biomass, before exploring how that carbon is degraded in both oxygen-rich (oxic) and oxygen-deficient (anoxic) environments. These biogeochemical processes are affected by ecological interactions, including competition for limiting nutrients, viral lysis, and predation by various protists in soils and aquatic habitats. The book neatly connects processes occurring at the micron scale to events happening at the global scale, including the carbon cycle and its connection to climate change issues. A final chapter is devoted to symbiosis and other relationships between microbes and larger organisms. Microbes have huge impacts not only on biogeochemical cycles, but also on the ecology and evolution of more complex forms of life, including Homo sapiens..