MYCOLab Ai Logo - gold and army green

In vitro interactions between Bradyrhizobium spp. and Tuber magnatum mycelium

Summary

Scientists have successfully grown white truffle mycelium in the laboratory for the first time by discovering its natural partnership with nitrogen-fixing bacteria called Bradyrhizobium. These bacteria and the truffle mycelium need each other to survive and grow together on culture medium. This breakthrough could revolutionize white truffle cultivation, which is currently difficult and expensive, by allowing farmers to grow truffle-producing plants more efficiently in controlled conditions.

Background

Tuber magnatum is the most expensive truffle species, but large-scale cultivation remains challenging compared to other Tuber species. T. magnatum mycelium has never been successfully grown in vitro until now, hindering scientific studies and cultivation applications. During soil development, ectomycorrhizal fungal mycelium interacts with various microorganisms, including mycorrhiza helper bacteria that may affect fungal metabolism and growth.

Objective

This study aimed to isolate and characterize T. magnatum mycelium and its associated bacteria to enable consistent in vitro growth and investigate the reciprocal dependency between the truffle mycelium and co-isolated bradyrhizobia.

Results

Three T. magnatum strains were successfully isolated and maintained in vitro for the first time. Nine bacterial isolates belonging to five Bradyrhizobium subclades within a new monophyletic lineage in the B. jicamae supergroup were identified. All bacterial isolates possessed nifH genes indicating nitrogen-fixing capacity, and the bacteria were unable to grow on mWPM without mycelium, demonstrating mutual dependency.

Conclusion

This first report of consistent T. magnatum mycelium growth in vitro has important implications for developing new white truffle cultivation technologies and conducting further studies on T. magnatum biology and genetics. The specific mutualistic interaction between T. magnatum mycelium and Bradyrhizobium species could enhance greenhouse mycorrhization processes and field soil colonization.
  • Published in:Environmental Microbiology Reports,
  • Study Type:Experimental Study,
  • Source: 10.1111/1758-2229.13271, PMID: 38692852
Scroll to Top