Guanidine is one of the most nitrogen-rich compounds. It could be a valuable source of organic nitrogen, but only very few organisms can access it. However, certain bacteria manage to obtain nitrogen from guanidine. A Konstanz-based research team led by chemist Professor Jörg Hartig and biologist Professor Olga Mayans has now discovered how this works. A newly discovered enzyme plays a key role – and, surprisingly, so does nickel. The research results were published on 9 March 2022 in the scientific journal Nature.
No growth without nitrogen
Nitrogen is an important component of all living organisms, and no growth is possible without nitrogen uptake. Although almost 80 percent of the atmosphere are nitrogen, the vast majority of life forms cannot access this reserve. They are thus dependent on chemically bound nitrogen, which is therefore also a pivotal component of fertilisers. However, where there is not enough nitrogen available, plants as well as many microorganisms quickly reach their limits.
There are nitrogen reserves in nature that are barely utilized: Guanidine is a widespread nitrogen-rich compound that excels by particularly high chemical stability. Due to this stability, it is hardly possible for organisms to obtain the vital nitrogen from guanidine: They cannot "crack the nut", so to speak. Hence, many organisms are within reach of an abundant source of nitrogen – and yet cannot tap it.
A Konstanz-based research network led by chemist Professor Jörg Hartig and biologist Professor Olga Mayans has now identified a biochemical mechanism that enables certain microorganisms to extract nitrogen from guanidine. In nitrate-poor environments, this is a decisive advantage over competing organisms.
How the nitrogen mining works
