New Extremophiles: bacteria living on phosphorus. (Introduction)

by David Turell , Sunday, November 12, 2023, 18:03 (167 days ago) @ David Turell

May be a very ancient species:

https://www.sciencedaily.com/releases/2023/11/231110112455.htm

"'This bacterium subsists on phosphite oxidation, and as far as we know, exclusively on this reaction. It covers its energy metabolism this way, and can build up its cell substance from CO2 at the same time," explains Schink. "This bacterium is an autotrophic organism, like a plant. It does, however, not need light like a plant, as it draws its energy from phosphite oxidation." Surprisingly, it turned out that the bacterium is not only a new species, but actually forms an entirely new genus of bacteria.

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"They produced a pure culture of this new bacterial strain, in which they were finally able to identify the key enzyme that triggers the oxidation of phosphite to phosphate.

"'The breakthrough came with Nicolai Müller and his enzyme experiments," says David Schleheck. Nicolai Müller succeeded in clearly demonstrating the enzyme's activity, thereby uncovering the biochemical mechanism behind the key enzyme. Olga Mayans and Jennifer Fleming created a three-dimensional model of its enzyme structure and active centre to understand the reaction pathway.

"'What was very surprising was that during its oxidation, phosphite is apparently coupled directly to the energy-carrier precursor AMP, whereby the energy carrier ADP is created. In a subsequent reaction, two of the generated ADPs are converted to one ATP, on which the organism ultimately lives," Nicolai Müller outlines the reaction pathway.

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"...the research team thinks that this type of metabolism is by no means new, but very old, even ancient: around 2.5 billion years old.

"'It is assumed that in the early days of evolution, when the Earth was cooling down, phosphorus was still present to a large extent in a partially reduced form and was only later gradually oxidized. The metabolism we have now discovered fits very well into the early phase of the evolution of microorganisms," Bernhard Schink explains.

"The biochemical mechanism that the bacterium uses for its metabolism is therefore not new, but has most probably been preserved from the primeval times of our planet: back when life on our planet began and the first microorganisms had to feed on inorganic compounds such as phosphite. Thus the new scientific findings provide clues to the early biochemical evolution on our planet. In addition, they provide the key to a biochemical mechanism that makes life possible in very hostile places, possibly even on alien planets."

Comment: another example of how life can use many avenues for energy production.