Anaerobic bacteria

In the beginning there was no oxygen. The anaerobes ruled the earth at that time and they continue to play an important role in our oxygenated world, in food microbiology, microbial ecology and bacterial pathogenesis. Welcome to this special issue of Microbiology Australia, which is dedicated to anaerobic microbes.

Anaerobes represent an extraordinarily diverse group of microbes that thrive in many environments, including the gastrointestinal tracts of humans and many animals, food, soil, sediments, subsurface aquifers, and other environmentally extreme habitats. Their activities have attracted wide attention, beginning with the demonstration by Louis Pasteur in 1861 that yeast cells produce ethanol by fermentation. Many important anaerobic processes have been revealed in subsequent studies. Metabolically, anaerobes catalyse reactions that are critical to the global cycling of carbon and other elements, environmental detoxification, biocorrosion, biofuel production, methanogenesis and waste treatment. Anaerobes also encompass formidable pathogens of humans and animals, exemplified by Clostridium species among many others. This group of organisms therefore has exceptional economic, medical, veterinary and academic importance in our world.

This issue presents 11 articles that offer insights into anaerobic microbiology with an Australian focus, highlighting some of the important areas of current relevance to our part of the world. Clostridium difficile is discussed from a number of different perspectives, beginning with a clinical view and a discussion of factors that contribute to infection and disease and moving on to genomic variation. A thought-provoking article on community-acquired and food animal C. difficile infection is included, bringing a ‘One-Health’ dimension to our understanding of C. difficile epidemiology in Australia. Other disease-causing clostridial species are also discussed, starting with Clostridium perfringens and its plethora of toxins and extending into an examination of C. perfringens-mediated necrotic enteritis in chickens. Given the current, and growing, veterinary importance of clostridial diseases, the article on the manufacture of veterinary clostridial vaccines is timely. A discussion of anaerobic spirochaetes and their importance in animals provides another dimension to the theme of disease pathogenesis. Rounding out the issue are articles with a focus on interesting anaerobes in the environment, including a discourse on bioremediation of organohalide pollution. Finally, the cutting-edge approach of coupling anaerobic bacteria and microbial fuel cells as whole-cell environmental biosensors is described, providing food-for-thought as we move into a new age of environmental awareness.

The Australian Society for Microbiology is pleased to showcase anaerobic microbes in this special issue. Australia has been a driving force in the study of anaerobes and is leading the way in many aspects, including understanding disease pathogenesis mechanisms, developing preventative measures and vaccines and applying knowledge of anaerobes and anaerobic processes to environmental problems. We hope you find this special issue relevant and valuable. We would like to thank Ian Macreadie and the Microbiology Australia editorial team for guiding us through the production of this issue and all of the authors for their carefully considered contributions.