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Uncovering the Secret Role of Viruses in Hot Composting: New Study Reveals Surprising Findings

A new study has uncovered the secret role of viruses in breaking down organic matter in compost.

While bacteria are known to play a major role in nutrient cycling, researchers have often overlooked the role of viruses in composting.

Using advanced techniques, scientists have delved into the impact of compost bacteria and their viruses during industrial-scale composting. 

The researchers investigated a form of hot composting called Hyperthermophilic, where temperatures reach up to 90 degrees Celsius.

The study found that as the population of bacteria in the compost grows, so does the population of viruses that target those bacteria.

This affects the overall composting process by changing the community of microorganisms.

The researchers found that when the ratio of viruses to bacteria was high, nutrients retrieved from organic material were also high.

This suggests that viruses play a crucial role in ecosystem functioning and nutrient cycling in compost.

DNA viruses also helped break down bacteria and use the bacteria’s genes to process carbon and nutrients, helping to recycle organic waste in compost.

Intriguingly, not all the viruses were harmful to bacteria – with some actually improving the ability of bacteria to survive under environmental stress.

This study shows that viruses are an important part of the composting ecosystem, working alongside (and sometimes inside!) bacteria to break down organic matter and recycle nutrients.

The researchers also suggested that viruses could be used as indicators of how well the composting process is working, allowing commercial composters to optimize the composting process. 

The study only looked at hyperthermophilic composting, which is not typically used in home composting. Therefore, it is unclear if this process is similar in cooler systems.

However, while the role of viruses in nutrient cycling in oceans has been well studied, their role in the soil and the composting process has not been well studied until now.

This fascinating study suggests that they could be a crucial part of the composting ecosystem.


Liao, H., Liu, C., Ai, C. et al. Mesophilic and thermophilic viruses are associated with nutrient cycling during hyperthermophilic composting ISME J (2023).

Read more

The Science of Composting: How Compost Happens
The Mind-Boggling Role Of Bacteria in Compost
The Pathogen-Destroying Power of Composting

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