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A chemical equation showing hydrogen peroxide being broken down to water and oxygen by catalase. Below is an image of hydrogen peroxide in a bottle and contact cleaner.
Catalase enzymatically converts highly reactive hydrogen peroxide (H 2 O 2 ) into water and oxygen. Hydrogen peroxide can be used to clean wounds. Hydrogen peroxide is used to sterilize items such as contact lenses. (credit photos: modification of work by Kerry Ceszyk)

Plasma, a hot, ionized gas, described as the fourth state of matter, is useful for sterilizing equipment because it penetrates surfaces and kills vegetative cells and endospores. Hydrogen peroxide and peracetic acid , another commonly used peroxygen, each may be introduced as a plasma. Peracetic acid can be used as a liquid or plasma sterilant insofar as it readily kills endospores, is more effective than hydrogen peroxide even at rather low concentrations, and is immune to inactivation by catalases and peroxidases. It also breaks down to environmentally innocuous compounds; in this case, acetic acid and oxygen.

Other examples of peroxygens include benzoyl peroxide and carbamide peroxide . Benzoyl peroxide is a peroxygen that used in acne medication solutions. It kills the bacterium Propionibacterium acnes , which is associated with acne. Carbamide peroxide, an ingredient used in toothpaste, is a peroxygen that combats oral biofilms that cause tooth discoloration and halitosis (bad breath). Yao, C.S. et al. “In vitro antibacterial effect of carbamide peroxide on oral biofilm.” Journal of Oral Microbiology Jun 12, 2013. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3682087/. doi: 10.3402/jom.v5i0.20392. Last, ozone gas is a peroxygen with disinfectant qualities and is used to clean air or water supplies. Overall, peroxygens are highly effective and commonly used, with no associated environmental hazard.

  • How do peroxides kill cells?

Supercritical fluids

Within the last 15 years, the use of supercritical fluids , especially supercritical carbon dioxide (scCO 2 ), has gained popularity for certain sterilizing applications. When carbon dioxide is brought to approximately 10 times atmospheric pressure, it reaches a supercritical state that has physical properties between those of liquids and gases. Materials put into a chamber in which carbon dioxide is pressurized in this way can be sterilized because of the ability of scCO 2 to penetrate surfaces.

Supercritical carbon dioxide works by penetrating cells and forming carbonic acid , thereby lowering the cell pH considerably. This technique is effective against vegetative cells and is also used in combination with peracetic acid to kill endospores. Its efficacy can also be augmented with increased temperature or by rapid cycles of pressurization and depressurization, which more likely produce cell lysis.

Benefits of scCO 2 include the nonreactive, nontoxic, and nonflammable properties of carbon dioxide, and this protocol is effective at low temperatures. Unlike other methods, such as heat and irradiation, that can degrade the object being sterilized, the use of scCO 2 preserves the object’s integrity and is commonly used for treating foods (including spices and juices) and medical devices such as endoscopes. It is also gaining popularity for disinfecting tissues such as skin, bones, tendons, and ligaments prior to transplantation. scCO 2 can also be used for pest control because it can kill insect eggs and larvae within products.

Questions & Answers

Explain Mould
Chinenye Reply
Explain mycoses and it's classification
Chinenye
why do we have hiccups?
Manisha Reply
shakey diaphragm
Curlisse
The antibody binding site is formed primarily by:
Asalla Reply
How many types of MICROORGANISMS do we have?
Hope Reply
Hello friends
Hope
What's pathogenesity
Usman Reply
something that causes disease
Anietie
who is the father of microbiology?
Hope
no it is not it also dealt withe fermentation techniques, downstream processing of isolated products etc
Ramchandra Reply
hy
Abdul
hy
Roshan
you from
Abdul
I'm from Bangalore, India
Shanu
in banglore
Prabhat
what group is Indian
Abdul
I'm from pune
Vitthal
ok
Abdul
Why scientists is not studies the drungs or vaccines of a virus, based on common characterstics of virus as living and non-living organisms?
demisew
what are the examples of viruses and their causing agent
kolawole Reply
coronavirus in the family of Coronaviridae and the causing agent is common cold where it spread easily compared to hot region.you can correct me if I am wrong.
nyakaraitta
👍
Puja
what
nkechi
okay there are major 3 groups (1.Enterovirus=poliovirus, cocksakievirus A&B,echovirus,endovirus etc causing poliomyelities,meningitis, fever,respiratory disease, acute hemorrhagic conjunctivitis, 2.Hepatitis virus- infectious hepatitis , 3.Rotavius incl.coronavius =vomiting, diarrhoea and common co
nyakaraitta
isthe another virus are coronaviridae
anuush
Hai Puja
Shanu
g
Abdul
corona virus is not dangerous but not care is very dangerous..............
Abdul
👍
Puja
he means if we take care we will not be infected
abel
yeah
Abdul
for the question thing first let's classify viruses then it would be easier to deal with zem
abel
Where you all from?
Shanu
Pakistan
Abdul
what are five elements that are needed for bacteria to grow?
Florence
proper acidity (ph)
Abdi-fatah
salt level
Abdi-fatah
Temperature
Bejide
osmotic pressure,oxygen,light
abel
but zey are not only five n we can classify zem as physical and chemical
abel
air in hydrogen and carbon and niterogin
Abdul
1. Possible complications and outcomes for cutaneous anthrax:
Firoj Reply
chlamydia can it be viral disease?
nyakaraitta Reply
noh
Vitthal
what is microbiology
Sohel Reply
is the study of tiny organisms with the use of microscopes
Bejide
Is the study of microorganisms
Usman
is the biological science of identification and charaterization of micro organisms surrounding the environment
Jojo
what are the major groups of archae bacteria
Brian Reply
methanogens, halophiles, thermophiles
Mahalakshmi
Right, mali
vivek
yeah!!
Mahalakshmi
yes
nyakaraitta
right
Jojo
how can get information
Raage Reply
how i study microbiology
Raage
By Reading About It
Rajat
quickest form
Raage
why do our brain needs glucose?
Bijay Reply
b/c our brain works glucose as the other body use insulin
Cabdi
of course why do hairs obtain nutrients yet there is no blood?
nyakaraitta
can I get a diagram of paramicium
nyakaraitta
what is the meaning of the term microbiology
Mary Reply
 study of all living organisms that are too small to be visible with the naked eye.
Nnamdi
yahh it right
Stavan
wow lovely
Psalm
Well said.
Shanu
study of microscopic organism like protozoa, bacteria, fungi, algea ,viruses betc
Dr
what are the career opportunities in microbiology
Anietie
I don't understand the explanation
Nancy Reply
ok
Cabdi
virus can also culture?
anuush
ya same doubt.. virus can also culture?
Prabhat
prabhat explain More
Prince
yes we can culture virus. virus culture is a laboratory test in which samples are placed with a cell type that the virus being tested for is able to infect.
Feby
the topic is telling us on how the first microscope is been invented by van Lee...., & his own still remains the best although he's was a simple one with one lens while the compound one that was invented by Hooke with two lenses is the one commonly used now.
Esumeh
sorry! Hooke didn't invent it rather he used it in the writing of his book .
Esumeh
what is microbiology
Sohel
microbiology is the study of microrganisms (unicellular,multicellular) which can be seen under the microscope
Andrre

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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