An enzyme that can help release organic phosphorus from the environment has been identified in a new study from the University of Sheffield’s Institute for Sustainable Food.
Known as PafA, the identification of the enzyme could have huge ramifications for agriculture, the biggest consumer of non-renewable inorganic phosphorus worldwide.
Phosphorus is an essential nutrient for healthy growth and development for all organisms on Earth – both plants and animals. As a result, it is a crucial ingredient in many fertilisers.
In nature, phosphorus requires enzymes – known as phosphatases – to release it from its complex organic form. This is how plants and algae can use it as a nutrient naturally. However, it is typically hard to extract from the natural environment because of its complex chemical makeup.
PafA is an abundant bacterial phosphatase which has previously been overlooked as a solution. Studies conducted by the university have shown is can efficiently release the phosphorus which is needed for fertilisers in a way that other enzymes known to scientists can’t.
Dr Ian Lidbury, from the University of Sheffield’s Institute for Sustainable Food and Arthur Willis Environmental Research Centre, said: “The accumulation of phosphate can inhibit enzyme activity in the most common phosphatases, but PafA is unique in that its function does not suffer when phosphate accumulates.”
The most common form of phosphorus currently used in fertilisers is non-renewable, inorganic phosphate. There are several risks associated with using inorganic phosphate, one of the biggest being that global supplies are limited, which threatens food security.
The continued Russian invasion of Ukraine has put even more stress on the global food system. Russia is the world’s leading exporter of fertiliser chemicals like ammonium nitrate, phosphate and potassium, and the conflict has driven fertiliser prices up significantly.
This was one of several reasons which led the UK Government to publish new guidance on fertiliser use for farmers earlier this month.
As the world’s premier fertiliser exporter, Russia would usually supply some of the biggest agricultural exporters like Brazil and the US – the result of it not doing so this year will be felt globally.
As Dr Lidbury explained, there is a high occurrence and diversity of PafA in the environment, both on land and in aquatic environments, and so this discovery could be “crucial to help us reducing our reliance on – and the damage caused by rapidly using up – the world’s limited stocks of non-renewable chemical phosphorus fertilisers.”
“Our further research will investigate how PafA functions, as Flavobacterium forms appear to be particularly active compared to others,” he added. “Understanding this is crucial for us to be able to engineer optimised enzymes for use in agriculture.”
Once this is better understood, the team will work on how PafA can be introduced into sustainable agriculture.