The discovery of a century-long microorganism that lives on manganese is over.
Microbiologists at the California Institute of Technology have discovered bacteria that feed on manganese and use this metal as a source of calories. It is expected that this microorganism has existed for more than a century, but it has not yet been discovered or described.
Caled Leadbetter, a professor of environmental microbiology at the California Institute of Technology, and the postdoctoral scholar Hang Yu described these findings in the July 16 issue of Science: “These bacteria are The first bacteria found to use manganese as fuel.” nature. “One of the wonderful aspects of microorganisms in nature is that they can metabolize seemingly impossible substances (such as metals) and produce energy that is useful to cells.”
Research also shows that bacteria can use manganese to convert carbon dioxide into biomass, a process called chemical synthesis. Previously, researchers knew that bacteria and fungi would oxidize manganese or deprive electrons, but they just speculated that microorganisms that have not been identified may be able to use this process to promote growth.
Leadbetter stumbled upon this bacterium after conducting an unrelated experiment, which used a light chalk-like manganese. A few months before leaving school to work, he had placed a glass jar filled with substances in his Caltech office sink and soaked it in tap water. When he came back, the jar was painted with dark material.
“I thought,’What is that?'” he explained. “I began to wonder whether the microorganisms that need to be pursued for a long time may be the cause of this situation, so we systematically tested to find out the cause.”
The black coating is actually manganese oxide produced by newly discovered bacteria, most likely from the tap water itself. He said: “There is evidence that the relatives of these creatures live in groundwater, and part of Pasadena’s drinking water is drawn from the local aquifer.”
Manganese is one of the most abundant elements on the surface of the earth. Manganese oxides are dark, massive substances that are common in nature. They have been found in underground sediments and can also be formed in water distribution systems.
Leadbetter said: “There is a series of environmental engineering literature about drinking water distribution systems that are blocked by manganese oxide.” “But the way and reason for producing this material is a mystery. Obviously, many scientists think that bacteria may use manganese as an energy source, but to So far, there is no evidence to support this idea.”
This discovery helps researchers better understand the geochemistry of groundwater. As we all know, bacteria can degrade pollutants in groundwater, a process called bioremediation. When doing so, several key organisms will “reduce” manganese oxide, which means that they donate electrons to the human body in a manner similar to the way humans use oxygen in the air. Scientists have always wondered where manganese oxide comes from.
Leadbetter said: “The bacteria we discovered can produce this kind of bacteria, so they enjoy a way of life and can also provide other microorganisms with what we need to carry out the reactions we think are beneficial and ideal.”
The results of the study may also be related to understanding manganese nodules spread across the seafloor. These round metal balls may be as big as grapefruit, and were well known to marine researchers as early as the 1870s when the HMS Challenger sailed. Since then, it has been found that this nodule spreads across the bottom of many oceans on the planet. In recent years, mining companies have been planning to harvest and develop these nodules, because rare metals are often found concentrated in them.
But people know nothing about the formation of tuberculosis. Yu and Leadbetter now want to know whether microorganisms similar to the microorganisms they found in fresh water will work, so they plan to investigate the mystery further. Yu said: “This highlights the need to better understand marine manganese nodules before they are completely removed before mining.”
Woodward said: “This discovery by Jared and Hang fills a major knowledge gap in our understanding of the Earth’s element cycle and adds manganese (a profound but common transition metal) that shapes the evolution of life on Earth. Multiple ways.” Fischer, a professor of geobiology at the California Institute of Technology, did not participate in the study.
Reference: “Hang Yu and Jared R. Leadbetter” “Chemical Autotrophic Bacteria through Manganese Oxidation”, July 16, 2020, nature.
The research was funded by NASA And California Institute of Technology.