A study published in the magazine Microbiome reports that Norwegian Molids (Picea Abies) concentrate gold nanoparticles with the help of bacteria living in them.
“Our results suggest that bacteria and other microbes that live inside the plants can influence the accumulation of gold in trees,” said Kaisa Lehosmaa, ecologist at the University of Oulu, Finland, the main author of the study, reports Noi.md with reference to.
These resident bacteria are known as endophytes, symbiotic microorganisms that facilitate hormone production and nutrient absorption, among other functions. In the spruce, these bacteria segress the gold soluble particles that the trees absorb from the water through the roots, according to livescience.
The process is a form of biomineralization, in which living organisms control the formation of minerals in their tissues through a wide range of processes. In this case, endophytes have probably concentrated particles to reduce their toxicity.
For the study, the researchers investigated the lips near the Kittilä mine in northern Finland, the largest gold producer in Europe. The researchers examined 138 needles from 23 spills. Those from four of the trees contained golden nanoparticles.
Nanoparticles were surrounded by biofilms created by bacterial genres such as P3OB-42, Cutibacterium and Corynebacterium. These films are polysaccharides (complex sugars) and protein compounds secreted by bacteria, which allow them to persist in plant tissues.
The close association between nanoparticles and bacterial biofilms indicated that bacteria were probably responsible for the isolation of the mineral. The diversity of bacterial species was lower in needles containing gold. Other studies on plants with high concentrations of metals in their tissues have also found a decrease in microbial biodiversity.
No one will make wealth by cutting spruce to distill the very small amounts of gold in their needles, the particles measure only a million millimeter. However, the absorption of the valuable mineral by the trees can be a useful indicator of the gold deposits below the surface.
“Screening for such bacteria in the leaves of plants can facilitate the exploration of gold,” Lehosmaa said.
