New studies have found a fascinating connection. A strain of bacteria commonly found in Norway spruce needles is behind the buildup of microscopic gold nanoparticles. Researchers from the Geological Survey of Finland (GTK) explored the understudied contributions of endophytic microbes on plant biomineralization processes. Published in the journal Environmental Microbiome, this research could save gold explorers millions.
To investigate the effects of gold nanoparticles, the research team used scanning electron microscopy (SEM) to identify gold nanoparticles. Measuring only a millionth of a millimeter, these ultrafine particles were discovered in needle tissues of four Norway spruce trees. These findings demonstrate that the majority of these nanoparticles are surrounded by microbial biofilms. This illustrates the fascinating interplay between microorganisms and the accumulation of gold in plant tissues.
Bacterial Influence on Gold Accumulation
Postdoctoral researcher Kaisa Lehosmaa emphasized the significance of these findings, stating, “Our results suggest that bacteria and other microbes living inside plants may influence the accumulation of gold in trees.” The localized occurrence of gold nanoparticles within the spruce needles highlights the potential of these microorganisms to shape biogeochemical processes inside higher plants.
Dr. Lehosmaa continued, “In the soil, gold is available in ionic, soluble and liquid form. Transported by rain and water, the gold travels deep into the cells of spruce needles. The tree’s microbes are then able to precipitate this soluble gold back into solid, nanosized particles. This new insight tells us something amazing! Some bacteria that are associated with spruce trees are capable of transforming soluble forms of gold into insoluble particles within the needle tissues of the tree.
Peer-reviewed research further demonstrates that these nanoparticles are essentially invisible to the naked eye. They are so small that to collect them for commercial use is physically impossible. Their presence raises intriguing questions. How do bacteria contribute to nutrient cycling and mineral deposition within forest ecosystems?
Implications for Gold Exploration
The excitement surrounding this research reaches far past just the knowledge gained about plant biology, as it has the potential to completely transform methods to explore for minerals. Dr. Lehosmaa noted, “This insight is useful since screening for such bacteria in plant leaves may facilitate gold exploration.” Scientists are able to identify universal bacterial communities responsible for gold accumulation. The commercialization of this discovery will result in groundbreaking new ways to find gold deposits in nature.
It was emphasized by Research Professor Maarit Middleton that biogeochemical methods have a long-standing application in mineral exploration. She said this recently published research goes a long way in advancing the understanding of what’s happening with these processes. “Such biogeochemical methods have already been used in mineral exploration, but this new research enhances our understanding of what is actually happening in the process,” she stated.
Moreover, Professor Anna Maria Pirttilä remarked on the broader significance of endophytic microbes, stating, “These so-called endophytic microbes may play a role in plants’ biomineralization processes.” This view presents exciting opportunities to explore the role of microorganisms in modulating mineral content across plant taxa. It tracks adoption of their impact on many ecosystems.
Future Research Directions
The study’s results provide a good foundation for researchers to explore greater levels of bacteria-metal interactions within the plant system. Dr. Lehosmaa stated that there is a need for more research into the process of biomineralization in different plant species. For instance, metals can precipitate inside moss tissues. Research into biomineralization leads to incredible potential. Piccolo said it allows us to explore the potential for directly studying aquatic mosses as a biological means of metal remediation.
This study peels back the layers of complex interactions that drive nutrient cycling in forest–stream ecosystems. It highlights real-world examples of innovative environmental science and sustainable mining practices. Researchers have been heavily focusing their efforts on examining these microbial mechanisms. Through this microbial sleuthing, their research will help shed further light on the intricate interactions between plants, bacteria, and metals.