Microbiology Uv Light Lab Report

lifetime to ultraviolet light can cause Squamous Cell Carcinoma. It can occur in different areas of

The sun is a source of UV light that is very hard for most people to escape. It affects our cells in various ways and sometimes causes cell death. In this experiment, to inspect the damage done by UV irradiation on the genetic composition of Saccharomyces cerevisiae also known as common Baker’s yeast. The strains of this yeast used were the cells that were mutated and the TRP1 gene was inactive. In this strain, the cells would not be able to produce tryptophan, which they need in order to grow. Phenotypic reversion of this gene was examined by first spreading the cells on SD medium without tryptophan and a complete SC medium with tryptophan. The yeast on the SC medium while they SD mostly died on the plate. However, in part two of the experiment whenever these plates were exposed to UV light the TRP1 gene was reactivated and growth occurred. On the SC plates as time went on there were less colonies formed. In turn, on the SD plates the pattern of growth followed a bell shaped curve; there were more colonies after the plate was exposed to half the time maximum time then when the plate was exposed to the maximum time. These results indicate that mutagenesis of Saccharomyces cerevisiae did in fact occur.

In photodynamic antimicrobial chemotherapy (PACT), a combination of a photoresponsive agent and visible light causes selective destruction of microbial cells such as bacteria, fungi and viruses (Dougherty et al., 1998; Kalka et al., 2000; Konan et al., 2002). A number of studies have shown PACT to be highly effective in the in vitro destruction of viruses and protozoa, as well as Gram-positive and Gram-negative bacteria and fungi. The ability of visible light-photosensitising agent combinations to kill microorganisms has been known for over 100 years. PACT is an abbreviation and scientific term that stands for Photodynamic Antimicrobial Therapy. Photodynamic Antimicrobial Therapy (PACT) has been used effectively in medicine since the 1990s for the treatment of tumours, skin diseases and wound infections. The fungal cells, unlike human cells possess a cell wall. This cell wall is stained with a special photosensitizing gel-dye that is harmless to human cells but selectively makes fungi sensitive to a specific wavelength of light and means the bacteria and nail fungus is destroyed. PACT is used as an effective

The pulsed xenon ultraviolet light disinfection system works by using high intensity pulses to radiate UV light at frequencies that cross the germicidal UV range. This is the range in which microorganisms are susceptible to UV damage. The UV frequencies are able to harm the microorganisms by damaging cell walls and cellular structures which prevent replication. "It penetrates the cell wall of spores, viruses, and bacteria, so anything with DNA or RNA is susceptible," said Mark Stibich, PhD, MHS, BA, chief scientific officer for Xenex.

Ultraviolet (UV) light is an intermediate source of energy that can damage cells. The DNA in cells is especially sensitive to UV irradiation. The rings of the

Another type of extremophile is radio-resistant organisms. Radiation from the rays of the sun such as ultraviolet rays or any other source can damage cells in living organisms causing the premature death of cells as well as damaging the DNA within cells that can cause mutations of skin cells. This leads to cancers and other disorders relating to the improper coding of proteins as a result of damaged DNA. According to Gabani et al. (2013) organisms such as the bacterium Deinococcus radiodurans have adapted to withstand the harmful effects of radiation up to above the lethal dose of radiation. Other organisms that have been known to withstand the negative effects of a decaying radioactive isotope are

One room will be the control, no treatment will be used on this room, while the other two rooms will be treated with UV lamps and (UV-C)-reflective wall paint; a wall coating that reflects ultraviolet light to greatly increase the effectiveness of the UV lamp. It is expected that the bacteria in the untreated room will see an exponential growth in population over time because there are no human-controlled factors in place to limit the population size. It is expected that the bacteria in the ultraviolet light treated room will see an extinction of the population over time because the DNA of the microorganisms will be significantly damaged by the ultraviolet radiation. The damage to the genetic information of the bacteria will significantly decrease their ability to successfully reproduce, which in turn should cause rapid decay in populations. The population size of the bacteria in the experiment will be measured by the dry mass of cells after centrifugation. Within the UV-treated room, multiple disinfection techniques will be used. A room with a single stationary UV light, and a room with multiple stationary UV lights. It is expected that the room with multiple, stationary UV lights will require less time to significantly decrease the population of the bacteria than the room with a single, stationary UV light because its light covers more surface

Summary: Deinococcus Radiodurans is a gram-negative extremophile capable of resisting cell death by UV radiation. One interesting aspect of the bacterium is that its DNA is found in a coiled form and its cells are always found in either pairs or tetrads. Deinococcus Radiodurans has an extraordinary ability of repairing its DNA after being subject to extreme doses of radiating, levels significantly greater than what would

Microorganisms senses and respond to changes in environment. Certain types of Gram-positive bacteria species such as certain Bacillus and Clostridium species forms endospores when encountering environmental stress such as nutrient starvation [34] as shown in Fig 27. The bacterial spores differ significantly from the corresponding vegetative cells. Spores are metabolically dormant and exhibit resistance properties making them highly resistant to many treatments including extremes of temperature, radiation and chemical biocides[34] . The extraordinary resistance properties of endospores make them of particular importance because they are not easily killed by common biocidal agents.

Ultraviolet light (UV) Introduction The ultraviolet light is found around our lives, even if we do not concern about it too much. It is a kind of electromagnetic radiation that comes from the sun and people can not notice it with their eyes. The UV light only embodies 10% in the sun, and merely a little part reach on the ground. The UV light has the shorter wavelengths than the others. In addition, it also benefits our lives. We use the UV light on the periodontics, cleaning, the discovering of the real money, or dry out our nail. On the other hands, the UV light also has some negative impacts in our human bodies, the UV light mainly absorbed in the superficial, which means the dead layer of the epidermis.It can cause corneal burns, sunburn, seriously cause the skin cancer. Although it

When UV-B rays (ultraviolet light with shorter wavelengths than UV-A rays) penetrate the membrane of a cell, it can damage DNA, resulting in cell mutations, or cells dying off. In humans, this can lead to skin cancer and a changed immune system functioning, which can lead to other problems such as skin lesions. Exposure to UV-B rays can also result in the development of cataracts in the eyes and vision impairment. Similarly in plants, UV-B rays affect DNA and cell processes. These effects become apparent during photosynthesis, reducing plant sizes and harming reproductive and immune systems.

The impact of ultraviolet radiations on a human DNA is similar to that of a nuclear radiation. As a result, the immune system of body become

For example, V. parahaemolyticus cells induced into the VBNC state by exposure to cold temperatures happened to be more resistant to thermal inactivation (42 and 47 °C), low salinity, and acid inactivation (pH 4) (Wong, & Wang, 2004). Koga and Takumi (1995) reported that V. parahaemolyticus cells in the starved state became more resistant to subsequent environmental stresses such as heat (47 °C) or osmotic

Bacterial endospores are highly resistant structures that can withstand many forms of treatments, including heat and UV (Atrih & Foster, 2002), and this characteristic is facilitated by their unique spore structure. Bacterial capsules play an important role in the virulence of bacteria for their host, and enable bacterial cells to evade host defense mechanisms and survive hostile environments. The structure and function of endospores and capsules work specifically to benefit the microbial cell; furthermore, various physiological changes occur in these structures as a result of environmental stress (Sahin, et. Al., 2012). The specific mechanism of these physiological changes, the types of environmental stresses that cause the changes, and how these correlate with endospore and capsular structure and function are essential to the understanding of this topic.

Sunlight includes ultraviolet radiation, which can harm turf grass. Ultraviolet radiation is split into three different categories based on their wavelengths, UV-A, UV-B, and UV-C. UV-A has a wave length of 400-315nm, and is the least harmful to turf grass. UV-B has a wave length of 315-280nm, and is responsible for getting through the ozone layer and is the most harmful UV light to turf grass. UV-C has a wavelength of 100-280nm, but this wavelength never reaches the earth. The smaller the wavelength the more energy, and radiation with higher energy can penetrate deeper into the cells, causing more damage (Huylenbroeck and Bockstaele, 2001). Over exposure to ultraviolet radiation can be harmful to grasses and weeds, by damaging the grasses DNA, its proteins, lipids and membranes. With over exposure to ultraviolet radiation, grasses can undergo mutations when reproducing. Mutations are however, mostly negative, inhibiting vital cellular processes (DNA transcription and replication) and resulting in disturbed cellular function, sometimes even cell death (Busey and Davis, 1991).