Newly-discovered bacteria could be the holy grail for the copper industry

US and Brazilian researchers have published a new study in which they outline what they consider to be a "more efficient and safer" alternative to obtaining copper from bacteria. The work was published in the journal Science Advances. In their discussion, the scientists provide conclusive evidence of how a copper-resistant bacterium found in a copper mine in Brazil converts copper sulfate (CuSO4) ions into zero-valent Cu or metallic copper. "By putting the bacteria in an electron microscope, we could figure out the physics and analyze it. We found that the bacteria isolate monatomic copper," said Francisco C. Robles Hernandez, co-author of the study, in a news release. "In terms of chemistry, this is extremely difficult to deduce. Usually harsh chemicals are used to make individual atoms of an element. This bacterium makes it naturally. That is very impressive." According to Robles and his colleague Debora Rodrigues, the novelty of this discovery is that microbes in the environment can easily convert copper sulfate into zero-valent monatomic copper. This is a breakthrough because the current synthetic process to achieve the same result is usually not clean, labor intensive, and expensive. "The microbes use a unique biological pathway with a number of proteins that can extract copper (II) (Cu2 +) and convert it to monatomic, zero-valent copper (Cu0). The goal of the microbes is to create a less toxic environment for themselves by converting the ionic copper into monatomic copper, but at the same time they make something that is useful to us too, "says Rodrigues. According to the scientists, these results suggest that the conversion process could be an alternative to making individual atoms of metallic copper in a safer and more efficient way compared to current methods such as chemical vapor deposition, sputtering and femtosecond laser ablation. "We only worked with one bacterium, but that may not be the only one out there that does a similar job," Rodrigues said. "The next step for this particular research is to extract the copper from these cells and use it for practical applications." The research team believes these findings could be key to addressing the supply challenges arising from the limited availability of high quality copper in the earth's crust and the need for intensive smelting and production processes that require sulfur dioxide and nitrogen dioxide to make concentrate available in usable quantities.