Overview

• A peer-reviewed paper in Environmental Microbiome reports the first documented link between endophytic bacteria and gold nanoparticles in Norway spruce needles.
• Researchers from the University of Oulu and the Geological Survey of Finland examined 138 needle samples from 23 trees at a satellite deposit of the Kittilä gold mine using scanning electron microscopy and DNA sequencing.
• Gold nanoparticles were detected in needles from four trees and appeared within bacterial biofilms, with taxa including P3OB-42, Cutibacterium, and Corynebacterium more common in those samples.
• The authors propose that soluble gold moves with water into shoots where microbes precipitate it into nanosized particles, though the phenomenon is sporadic and localized.
• Potential applications include bio-based mineral exploration and metal-removal studies in mosses, but the particles are a millionth of a millimetre and not viable for commercial recovery.