Researchers from the University of Tokyo and others have discovered pockets of living microorganisms in mineral-filled veins in 2 billion-year-old rocks taken from South Africa’s Bushveld Igneous Complex.
The 2-billion-year-old mafic rocks of the Bushveld Igneous Complex reveal veins filled with clay minerals colonized by indigenous microorganisms (stained green). Image provided by: Suzuki others., doi: 10.1007/s00248-024-02434-8.
“We didn’t know whether rocks from 2 billion years ago were habitable or not,” says Dr. Yohei Suzuki, a researcher at the University of Tokyo.
“This is a very interesting discovery because the oldest geological formations in which living microorganisms have been found were 100 million-year-old deposits beneath the ocean floor.”
“By studying the DNA and genomes of these microorganisms, we may be able to understand the evolution of very early life on Earth.”
Dr. Suzuki and his colleagues analyzed rock samples from the Bushveld Igneous Complex, a rock intrusion in northeastern South Africa that formed when magma slowly cooled beneath the earth’s surface.
“The Bushveld Igneous Complex covers an area of approximately 66,000 km2 (about the same size as Ireland), varies in thickness by up to 9 km, and contains approximately 70% of the platinum mined worldwide. , contains some of the richest mineral deposits on Earth,” they said.
“Due to the way it was formed and the minimal deformation and changes that have occurred since then, the BIC is thought to have provided a stable habitat for ancient microbial life that continues to this day.”
The core sample, measuring 8.5 cm in diameter and 30 cm in length, was taken from a depth of 15.28 meters with the assistance of the International Continental Scientific Drilling Program, a non-profit organization that funds exploration of geological sites.
By analyzing thin slices of the rock, the researchers found that the cracks in the rock were packed with live microbial cells.
The crevices near these cracks were clogged with clay, making it impossible for living things to get out of them or for anything else to get in.
The researchers built on previously developed techniques to ensure that the microbes were native to the rock samples and not due to contamination during the drilling or testing process.
By staining the DNA of microbial cells and using infrared spectroscopy to observe proteins in the microbes and the surrounding clay, they confirmed that the microbes were alive and uncontaminated.
“I am very interested in the possibility that subsurface microorganisms exist not only on Earth, but also on other planets,” said Dr. Suzuki.
“Rocks on Mars are generally much older (20 billion to 30 billion years ago), but NASA’s Perseverance rover is currently scheduled to return rocks that are similar in age to the rocks used in this study.”
“Now that we have discovered microbial life in a 2 billion-year-old Earth sample and have been able to accurately confirm its authenticity, we are excited to see what we will find in Mars samples in the future.”
of result Published in a magazine microbial ecology.
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Yuya Suzuki others. 2024. Subsurface microbial colonization of mineral-filled veins in 2 billion-year-old mafic rocks of the Bushveld Igneous Complex, South Africa. microorganism ecole 87, 116; doi: 10.1007/s00248-024-02434-8
This article is based on a press release from the University of Tokyo.
Source: www.sci.news
