How does UV light affect the DNA and RNA of microorganisms?

UV light has a significant impact on the DNA and RNA of microorganisms by causing alterations that prevent replication. When microorganisms are exposed to UV light, it can lead to the formation of pyrimidine dimers in their DNA, which are covalent linkages between adjacent thymine or cytosine bases. This damage disrupts the normal base-pairing and can lead to mutations or halt the process of transcription and replication altogether.

As a result, the microorganisms cannot properly reproduce or produce proteins needed for their survival, effectively impairing their ability to grow and replicate. This highlights the important role of UV light as a disinfecting agent in wastewater treatment processes, where controlling microbial populations is essential for public health and environmental protection.