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How does UV radiation affect bacteria?

How does UV radiation affect bacteria?

Germ-Killing Light Targets the DNA & RNA of Microbes UV light produces electromagnetic energy that can destroy the ability of microorganisms to reproduce and cause inactivation of microbes by causing mutations and/or cell death.

What structure of the bacterial cell does the UV light damage?

Ultraviolet (UV) light kills cells by damaging their DNA. The light initiates a reaction between two molecules of thymine, one of the bases that make up DNA.

What is UV radiation in microbiology?

Ultraviolet germicidal irradiation (UVGI) is a disinfection method that uses short-wavelength ultraviolet (ultraviolet C or UV-C) light to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular functions.

Can bacteria survive UV radiation?

Contrary to the hypothesis that subsurface bacteria should be sensitive to UV light, the organisms studied exhibited resistance levels as efficient as those of surface bacteria. A total of 31% of the aerobic subsurface isolates were UV resistant, compared with 26% of the surface soil bacteria that were tested.

What are 3 types of UV radiation?

UV radiation is classified into three primary types: ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC). These groups are based on the measure of their wavelength, which is measured in nanometers (nm= 0.000000001 meters or 1×10-9 meters).

Can E coli survive UV light?

Radiation at 265 nm in the UV region was most efficient in killing the E. coli cells and 100% mortality was achieved at a dose of 1.17 log mJ/cm(2). In the visible spectrum, the radiation dosages required for a one-log reduction of the E. coli cell density at 458 and 488 nm were 5.5 and 6.9 log mJ/cm(2), respectively.

Does UV damage DNA?

One way ultraviolet light can harm cells is by directly damaging DNA. This is something many of us are reminded of every spring and summer – it’s the cause of sunburn! As the name suggests, direct DNA damage occurs when a photon of UV light hits DNA.

At what wavelength is UV most harmful to bacteria?

The UVC spectrum, especially the range of 250–270 nm, is strongly absorbed by the nucleic acids of a microorganism and, therefore, is the most lethal range of wavelengths for microorganisms. This range, with 262 nm being the peak germicidal wavelength, is known as the germicidal spectrum [6].

Why is UV light used in sterilization?

A: UVC radiation is a known disinfectant for air, water, and nonporous surfaces. UVC radiation has effectively been used for decades to reduce the spread of bacteria, such as tuberculosis. For this reason, UVC lamps are often called “germicidal” lamps.

What bacteria is resistant to UV?

A study from McKinney and Pruden20 observed that two Gram-positive organisms (Staphylococcus aureus and E. faecium, both Firmicutes) were more resistant to UV irradiation than two Gram-negative bacteria (E. coli and P.

What bacteria is most resistant to UV light?

Deinococcus radiodurans was the most resistant bacterium to both types of radiation, with a D37 value of 4.0 × 104 μWs cm−2 to UV light and 300 krads to gamma radiation.

How does UV radiation kill bacteria or cause changes in them?

Ultraviolet light kills microorganisms by damaging their DNA. UV radiation disrupts the chemical bonds that hold the atoms of DNA together in the microorganism. If the damage is severe enough, the bacteria cannot repair the damage and the cells die.

Does UV light kill bacteria?

Killing Bacteria with UV Light. UVC light is part of the ultraviolet light spectrum and emits a high frequency of UV light that makes it extremely effective at killing bacteria, viruses, mold and other pathogens.

What are the biological effects of UV radiation?

These effects include mainly sunburn (or erythema) and tanning (or pigment darkening). The chronic effects of UV exposure can be much more serious, even life threatening, and include premature aging of the skin, suppression of the immune system, damage to the eyes, and skin cancer. UV radiation can cause serious negative impacts on cells.

How does ultraviolet radiation damage living organism?

Ultraviolet (UV) photons harm the DNA molecules of living organisms in different ways. In one common damage event, adjacent bases bond with each other, instead of across the “ladder.” This makes a bulge, and the distorted DNA molecule does not function properly.