Course Hero Logo

70 isopropanol was used in quadrant a it acts as an

Course Hero uses AI to attempt to automatically extract content from documents to surface to you and others so you can study better, e.g., in search results, to enrich docs, and more. This preview shows page 10 - 12 out of 14 pages.

70% isopropanol was used in quadrant A. It acts as an antimicrobial which killsE.coliandS. aureusby damaging the cell wall of bacteria, dissolving their lipid membrane anddenaturing their proteins (Maitland, 2019; Erickson 2020). The molecules of isopropylalcohol will form bonds with the lipid membrane of the microorganisms causing the bondsbetween the lipid molecules to break. This leads to the denaturation of bacteria as itscomponents were exposed to the chemicals (Vandergriendt, 2020). 100% isopropanol is notsuitable for this experiment as it contains higher evaporation rate and shorter contact timewith microorganisms due to the low water content in the chemical.
Besides, 3% hydrogen peroxide can also disinfect bothE. coliandS. aureus.Hydrogen peroxide produces hydroxyl free radicals which are harmful and able to attack thelipid molecules of membrane, proteins such as DNA as well as the components of bacteria(Rutala and Weber, 2008). Hydrogen peroxide (H2O2) is a compound that has an extra oxygenatom than a normal water molecule. It will form into water (H2O) and oxygen (O2) when itreacts with catalase in bacteria cells and human cells. The formation of water and oxygen canbe explained as the cell wall of bacteria was oxidised by the oxygen atoms in H2O2, causingthe bond of the membrane to break and degrade (Melina, 2011). When bacteria were grew inthe quadrant containing H2O2, it will produce catalase to protect itself by using catalase tobreak down H2O2to water and oxygen. However, this self-protection method will onlyfacilitate the reaction between H2O2and catalase, increasing the degradation of bacteria(Rutala and Weber, 2008).Moreover for Decon-90, it is a surface active cleaning agent, also known asradioactive decontaminant that kills both Gram-negative (E. coli) and Gram-positive (S.aureus) bacteria. It is an alkaline that contains a pH of 13, and an emulsion that containsanionic and non-ionic surface active agents as well as non-phosphate detergent builders(Electron Microscopy Sciences, n.d.). These anionic and non-ionic surface active agentsplayed its role to inhibit the growth of bacteria especially for Gram-positive (S. aureus)bacteria which has a thicker peptidoglycan layer and presence of lipoteichoic acids (Falk,2019). Falk (2019) stated that anionic surfactants with the absence of acids will act as anantimicrobial that perform disinfecting activity.ConclusionThe objectives of this experiment focus on the changes of the area around the filterdiscs and effectiveness of the disinfectants in killing microorganisms have been determined.The principles behind each disinfectant have been studied.There were 4 types of disinfectant chemicals were used in this experiment, 70%isopropanol, 3% hydrogen peroxide, Decon-90 and sterile distilled water were used on testingchemical control ofEscherichia coliandStaphylococcus aureus. In 70% isopropanol withboth 24 and 48 incubation hours, the chemical killed the bacteria by dissolving the lipidmembrane and denaturing the protein of the bacteria only when the bacteria was exposed to

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 14 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Spring
Professor
N/A
Tags
Bacteria, Escherichia coli

Newly uploaded documents

Show More

Newly uploaded documents

Show More

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture