Authors: Katrin Weinhandl, acib & Simon Rittmann, Arkeon
Living fossils allow us a glimpse into a time long past, for they have changed little or not at all over millions of years. The platypus or the horseshoe crabs are well-known representatives from the world of animals; among plants, horsetail, ginkgo or the box tree are considered such living fossils. But the world of microorganisms can also come up with living fossils: the so-called archaea are a special group of microorganisms, which are characterised by a special composition of the cytoplasmic membrane and sometimes also through specific cell envelope that is not found in bacteria or eukaryotic organisms. Many archaea feel particularly comfortable under extreme conditions, such as high temperatures, high salinity, high pressure or extremely acidic or basic pH values. This is why they are found primarily in volcanic areas, in the deep sea, in the Dead Sea or in mud holes – and have been for millions of years!
These primordial microorganisms were classified as a separate group of organisms in the 1970s, but for some years now they have been attracting great interest, especially in biotechnology. Why? Because they are able to capture CO2, to produce biogas (methane), or to produce bioplastics. Their special cell wall properties (especially the S-layer proteins) are also of interest in medicine or are used in nanotechnology because they have a special two-dimensional structure.
In addition to the common bacterial (Escherichia coli) or yeast strains (Saccharomyces cerevisiae, Pichia pastoris, etc.), archaea could also become increasingly important for biotechnological production processes, as their preference for specific growth conditions often fits better with the reality of some industrial processes than strains that grow optimally at room temperature or neutral pH. The only drawback of archaea so far is their reputation for being more difficult to cultivate and slower growing due to their extremophilic nature. However, intensive research on these organisms has already overcome many initial hurdles, and the first products that are produced by archaea are already on the market.
The tiny methane producers are already being used in mixed-consortia to generate biogas or to be applied in so-called ore leaching. The potential of archaea is also evident in the production of fuel or renewable energy (e.g., by hydrogen-producing archaea). By coupling CO2-fixation with the production of amino acids, solutions can also be found in a very innovative way to secure the global supply of food for a growing world population, as is also the goal of the company Arkeon.
The research topic of “archaea” is booming, and with the constantly growing knowledge about this very special type of organism, completely new possibilities are opening up in biotechnology. Thus, the descendants of the oldest living organisms on this planet are helping to ensure a healthy climate for the life of tomorrow.
Picture credits: Unsplash