A vitamin can decode interactions between soil microbes

Corrinoids, a category of nutrients to which vitamin B12 belongs, influence the functionality of soil microbiomes, two UC Berkeley studies have found

by Matteo Cavallito

By investigating corrinoids, a family of nutrients to which vitamin B12 belongs, it is possible to identify the responses of microbes to their environment by assessing how they influence the function of the soil microbiome. This is highlighted by two different studies published in the Multidisciplinary Journal of Microbial Ecology. The research, by the University of California, Berkeley, examined the same kind of prairie soil and provided an overall picture.

“Inside just a handful of soil are billions of microbial organisms that live together as communities, sharing and competing for resources. Together, these communities impact the planet in astonishing ways, for example, by sequestering carbon from the atmosphere,” the researchers explain in a statement from the university.

Soil impacts on microbes in forests exposed to degradation

The relationship between microbes and vitamin B12

In one of these two studies, researchers isolated bacteria from soil and analyzed them in the laboratory. In particular, they cultivated more than 100 different bacterial species, 37 of which were discovered for the first time. “We isolated and characterized a taxonomically diverse collection of 161 soil bacteria from a single study site,” the authors explain.

Morevover, “Most corrinoid-dependent bacteria in the collection prefer B12 over other corrinoids, while all tested producers synthesize B12, indicating metabolic compatibility between producers and dependents in the collection.”

Surprisingly, noted Zoila Alvarez-Aponte, researcher and lead author of the study, “all the isolates either synthesize or prefer B12, in contrast to the dozen other corrinoids that have been discovered in many other environments.” The results, the study explains, “provide evidence for corrinoid-based metabolic interactions among bacteria and provide a framework for the study of nutrient-sharing ecological interactions in microbial communities.”

https://resoilfoundation.org/en/environment/permafrost-microbes-climate-change/

Corrinoids impact the microbial community

A second study focused on the impact of corrinoids on the soil environment and their ability to influence the composition of the microbial community. Scientists, first, noted a large abundance of vitamin B12 in the soil. By adding more, noted Alexa Nicolas, researcher and co-author of the study, “the composition of the bacterial community did not change, but the addition of alternate corrinoids caused distinct changes in the soil community.” The analysis identified which bacteria provide the nutrients while also highlighting their impact.

“Enrichment cultures and soil microcosms seeded with different corrinoids showed distinct shifts in bacterial community composition, supporting the hypothesis that corrinoid structure can shape communities,” the research explains.

The environmental context, in detail, would have influenced microbial community responses. “These results implicate corrinoids as key determinants of soil microbiome structure and suggest that environmental micronutrient reservoirs promote community stability,” the study concludes.

https://resoilfoundation.org/en/environment/soil-bacteria-climate-drought/

From study new ways to promote soil health

Microbes, the authors recall, play a decisive role in ensuring the balance of soils by helping soils maintain healthy ecosystems. Microorganisms, in fact, store organic matter, feed the nutrient cycle, retain and filter water and provide plant support. By acting on the microbiome, as a result, the overall condition of soils can be improved.

By demonstrating how the presence of certain vitamin B12-related nutrients affects the growth of individual soil bacteria in the laboratory and their survival in the soil, the researchers further note, the two studies thus pave the way for the development of new strategies for intervening on microbes to promote soil well-being.