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Harnessing Specialized Metabolism from Anaerobes

Anaerobic bacteria, a group of microorganisms that thrive in the absence of oxygen, have a significant impact on the quality of life on Earth. They play a crucial role in biotechnology and are essential components of the gut microbiota. As such, they are of tremendous importance for human, animal, and environmental health. On the other hand, certain anaerobes can be life-threatening pathogens. In light of this, there is an urgent need for a deeper understanding of the specialized metabolites of anaerobes, which could function as chemical mediators, virulence factors, and antibiotics. Although genome analyses indicate that anaerobic bacteria hold an enormous potential for producing structurally…

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 Breathing Without Air: The Remarkable World of Anaerobic Energy Production

Many organisms have adapted to thrive in environments completely devoid of oxygen, and their energy-making strategies are nothing short of fascinating. Instead of relying on oxygen, these creatures often turn to processes like fermentation, a kind of metabolic hustle that generates energy without needing that familiar gas. Think of it as a different kind of engine, one that can run on alternative fuels.

Articles of Interest

Anaerobes: General Characteristics

Anaerobes are potentially pathogenic when displaced from normal environments (human colon, soil) and implanted in dead or dying tissue; abscesses, pneumonias, and oral and pelvic infections result.

Aerobic Bacteria and Anaerobic Bacteria

At first glance, you might think all bacteria are created equal. However, they can be broadly categorized based on their oxygen requirements: aerobic bacteria need oxygen to survive, while anaerobic bacteria thrive without it. This distinction is not just academic; it shapes how these organisms interact with their surroundings and influence various biological processes.

Anaerobe

Anaerobic clinical microbiology remains a challenge due to specialist culture requirements, coupled with the increase in and spread of antimicrobial resistance. The normal human microbiota is primarily composed of anaerobic bacteria, and is now recognised as a source of life-threatening anaerobic infection. More recent metataxonomic and metagenomic sequencing has extended interest in the potential role of the microbiota in a plethora of other aspects of human health, from obesity to mental health. In addition, the successful use of faecal microbiota transplants for the treatment of clostridial infection raises potential unchartered long-term consequences and possibilities.

Anaerobes and heterotrophs

Anaerobes and heterotrophs are two distinct groups of organisms that play crucial roles in the ecosystem. Heterotrophs, which include familiar organisms such as animals, rely on primary producers—organisms that create energy-storing molecules like those produced through photosynthesis. In contrast, anaerobes are generally microscopic organisms that thrive in environments devoid of oxygen. Interestingly, it is believed that anaerobes were among the earliest organisms to evolve on Earth, thriving in the "prebiotic soup" rich in organic molecules.

Anaerobic Life—a Centennial View

Experiments that we perform today have roots. So, in this brief view from what we now believe to be the lofty vantage point of 1999, I would like to share with you some discoveries that I believe were pivotal to an understanding of anaerobic life.

Breathless Microbes: Life With No Oxygen

Recent advances in anaerobic microbiology have driven significant progress in biotechnology, environmental microbiology, and biochemistry. Anaerobes play key roles in sustainable biotechnological processes, including biomethanation, chain elongation for bio-based chemicals, and microbial electrosynthesis for carbon-neutral energy production.

Early Microbial Evolution: The Age of Anaerobes

. We also consider the perhaps more pressing issue that molecular phylogenies need to recover anaerobic lineages at the base of prokaryotic trees, because O2 is a product of biological evolution; hence, the first microbes had to be anaerobes.

Establishment of Oral Anaerobes during the First Year of Life

Anaerobic species constitute a significant part of the bacterial community of the mouth. Although the time and species involved in the primary colonization of infants are of great importance by forming the basis for further colonization, the development of the oral anaerobic microflora with age is still inadequately understood.

Microorganism Spotlight - Anaerobic Organisms

In short “anaerobe” means: To live without oxygen. Hence anaerobic organisms are organisms that do not require molecular oxygen (O2) to live and propagate. In contrast, aerobic organisms are dependent on the availability of O2 because they use it as a terminal electron acceptor in aerobic respiration. Thus, molecular oxygen - or dioxygen, how the most common state of the oxygen homodimer (O2) is called, serves as a critical component in energy synthesis.

Pasteur, oxygen and the anaerobes revisited

As a biochemist, Louis Pasteur focused on fermentation, demonstrating that it was a vital process. In 1860, he discovered anaerobic life and the strict anaerobes, particularly those responsible for butyric fermentation. Then, in spite of his lack of medical background, Pasteur turned to investigating the role of bacteria in human and animal diseases. In 1877, Pasteur and Joubert described for the first time a pathogenic anaerobe, the 'septic vibrio' (now Clostridium septicum).

The Anaerobic Way of Life

In aqueous systems, aerobic organisms rapidly consume dissolved oxygen so that deeper layers of many waters and soils (especially if they are rich in organic compounds), as well as mud and sludge, are practically anaerobic. Nevertheless, these areas are inhabited by numerous organisms that fulfill the important ecological role of converting insoluble organic material to soluble compounds and gases that can circulate back into aerobic regions. Other important anaerobic habitats are the rumen, the intestinal tract, and man-made anaerobic digesters of sewage treatment plants.

The Anaerobic Way of Life

The diversity of microorganisms able to thrive under anaerobic conditions is overwhelming. Up to now more than 200 genera of obligate anaerobic microorganisms have been described.

The Great Oxidation Event: How Cyanobacteria Changed Life

A silent, mysterious force worked to release oxygen steadily, until the very composition of the atmosphere changed. That mysterious entity happened to be a microbe: Cyanobacteria.

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Anaerobic Infections

Some infections are caused by bacteria that cannot survive or multiply when oxygen is present. These bacteria, called anaerobes, normally live in the GI tract, where there is only a limited amount of oxygen. By definition, the term anaerobic means “life without air.”

StatPearls

Anaerobes are part of the indigenous or native flora, particularly the oral cavity, human bowel, and female genital tract. The colonization with anaerobes varies with age, organ site, and environmental factors. For example, infants exclusively breastfed have gut flora with predominantly Bifidobacterium, with few Bacteroides and Enterococcus species. On the other hand, infants who are fed cow's milk have gut flora similar to that of an adult's, which contain gram-negative anaerobes and facultative bacilli.