Bacteria were first discovered by Antonie van Leeuwenhoek in 1676.
Bacteria come in a wide variety of shapes.
Colony of E. coli.
Sunday, April 15, 2012
Short Fun Fact List
There are about
5000000000000000000000000000000 (5x10^30) bacteria on earth.
Bacteria were first discovered by Antonie van Leeuwenhoek in 1676.
Bacteria come in a wide variety of shapes.
Colony of E. coli.
Bacteria were first discovered by Antonie van Leeuwenhoek in 1676.
Bacteria come in a wide variety of shapes.
Colony of E. coli.
"First, we should give thanks for microbes because they are intricately involved in digestion. The human diet is very complex -- we take in a plethora of plant and animal products. In order to digest many of these foods, we must rely on the tools that bacteria have at their disposal. While an individual species may only be able to use its tool to help digest one particular carbohydrate, the collective bacterial community comprises a large and diverse toolkit that can break down the smorgasbord of food we eat into usable energy.
Interesting work from the Jeffrey Gordon Lab at Washington University in St. Louis has shown that different groups of microbes are present in the guts of obese and lean twins1. Based on this finding, an ongoing area of research is to understand the connection between your microbial consortium, how it extracts energy from the food you eat and how this could be tied to obesity or leanness. Ultimately, a better understanding of these processes can possible lead to modulating your microbial communities to avert obesity (or diabetes, which microbes are believed to play a part in as well).
Furthermore, let's give thanks for our microbial friends because they play an essential role in the development of our immune system. Ever since birth, we are inoculated with microbes (thanks, Mom!). One of the most important functions of these microbes is to help the immune system mature and become fully functional. Studies in germ-free mice show that mice without their normal bacterial members suffer from a dysfunctional immune system2. An important area of focus is to understand how your immune system discriminates between foreign bacteria (e.g. E. coli in the last column) and the bacteria that are naturally present in your gut. This difference is important because it will give us basic knowledge of how our immune system discriminates friend from foe.
Lastly, let's say thanks to our microbial cooperators because of our mutual self-interest. In biology we call a relationship between two organisms that benefit both as a mutualistic relationship. In essence, our bodies are warm, wet and energy-rich: perfect for microorganisms to thrive. In exchange, we utilize bacteria for the enzymes and factors to help us break down food and for the proper development of our immune system to fend off parasitic pests. It's a beautiful example of the interconnectedness of the biological world.
Next time you are enjoying a meal or fighting off a cold, give due thanks to your microbes. They not only make our world better, they make it possible."
-Caleb Fischer
http://www.gcdailyworld.com/blogs/1589/entry/42781/
Interesting work from the Jeffrey Gordon Lab at Washington University in St. Louis has shown that different groups of microbes are present in the guts of obese and lean twins1. Based on this finding, an ongoing area of research is to understand the connection between your microbial consortium, how it extracts energy from the food you eat and how this could be tied to obesity or leanness. Ultimately, a better understanding of these processes can possible lead to modulating your microbial communities to avert obesity (or diabetes, which microbes are believed to play a part in as well).
Furthermore, let's give thanks for our microbial friends because they play an essential role in the development of our immune system. Ever since birth, we are inoculated with microbes (thanks, Mom!). One of the most important functions of these microbes is to help the immune system mature and become fully functional. Studies in germ-free mice show that mice without their normal bacterial members suffer from a dysfunctional immune system2. An important area of focus is to understand how your immune system discriminates between foreign bacteria (e.g. E. coli in the last column) and the bacteria that are naturally present in your gut. This difference is important because it will give us basic knowledge of how our immune system discriminates friend from foe.
Lastly, let's say thanks to our microbial cooperators because of our mutual self-interest. In biology we call a relationship between two organisms that benefit both as a mutualistic relationship. In essence, our bodies are warm, wet and energy-rich: perfect for microorganisms to thrive. In exchange, we utilize bacteria for the enzymes and factors to help us break down food and for the proper development of our immune system to fend off parasitic pests. It's a beautiful example of the interconnectedness of the biological world.
Next time you are enjoying a meal or fighting off a cold, give due thanks to your microbes. They not only make our world better, they make it possible."
-Caleb Fischer
http://www.gcdailyworld.com/blogs/1589/entry/42781/
The non-specific inflammatory response can be described as follows:
Once an injury to surrounding cells occur, mast cells and basophils (not shown) release histamines (also not shown) that attract neutrophils and cause vasodilation of the blood vessels closest to the injury. Neutrophils are the fastest to arrive and engulf the bacteria through phagocytosis. Some plasma containing small blood vessels and additional phagocytes will leak into the area surrounding the injury. Prostaglandins are also released, and these cause more dilation of the blood vessels. It also induces edema, or swelling, which explains why swelling occurs after an injury.
An intersting thing about pus: pus contains dead phagocytes and some plasma. Usually, the body will reabsorb pus within a few days of injury. However, sometimes it is released in other... methods.
Once an injury to surrounding cells occur, mast cells and basophils (not shown) release histamines (also not shown) that attract neutrophils and cause vasodilation of the blood vessels closest to the injury. Neutrophils are the fastest to arrive and engulf the bacteria through phagocytosis. Some plasma containing small blood vessels and additional phagocytes will leak into the area surrounding the injury. Prostaglandins are also released, and these cause more dilation of the blood vessels. It also induces edema, or swelling, which explains why swelling occurs after an injury.
An intersting thing about pus: pus contains dead phagocytes and some plasma. Usually, the body will reabsorb pus within a few days of injury. However, sometimes it is released in other... methods.
Wednesday, April 11, 2012
Final Product Ideas
For the rest of my ISP, I am planning on synthesizing the information I have gathered on bacteria in an essay no more than 4000 words, possibly in the form of a thesis. Here is a short snippet from my essay so far:
The diversity of bacteria is sustained by their short generation span.
Constantly adapting to changing environments, they have the ability
to have an omnipresent impact on human life, as well as on the lives of other
animals.
The intestinal bacterium E. coli is the epitome of such
diversity. Through extensive studies, E. coli has presented
most of the information we now know about bacteria. The double-stranded,
circular DNA molecule is important to the bacterial genome: it is tightly
packed in a region called the nucleoid and does not contain a binding membrane.
Another characteristic that sets bacteria apart from eukaryotic
organisms is that they contain several plasmids that are not necessary for
survival, but may be beneficial in harsh environments—another factor that adds
to the malleability of these microbes.
Bacteria, including E. coli, are also extremely successful
because of their ability to proliferate so rapidly through asexual
reproduction. It has been calculated that approximately nine million E.
coli genes are mutated through this process per day per human host. This
data supports the conclusion that bacteria can adapt to an environment through genetic
mutation; those that survive will go on to reproduce. Though mutations are a
major source of variation within a bacterial population, a process called genetic
recombination can add more diversity to a population.
One study involving E. coli proves this. Wild-type E. coli (non-mutant) can survive only on a medium of
glucose. However, two mutant strains, one of which cannot produce tryptophan,
and the other that cannot synthesize arganine. When both the strains were mixed
together and incubated on a minimal medium, growth occurs, showing that genetic
recombination has occurred, making the two individual strains successful in an
environment containing a minimal nutrition source.
In addition to being so versatile independently, bacteria can be used by
scientists to exemplify certain genes present in non-bacterial organisms. A
certain gene of interest (from any cell, including eukaryotic ones) can be
isolated and inserted into a plasmid from a bacterial cell. The plasmid containing
the gene of interest can be placed back into the bacterial cell, which is then
cloned. When the bacteria reproduce, only some express the gene of interest.
This strain of the bacteria can then be used for a variety of things, such as
pest resistance for plants, or the treatment of stunted growth in animals.
Another piece of evidence showing that bacteria are extremely successful
on earth is that bacteria were some of the first organisms to appear on the
planet, about three thousand five hundred million years ago. The fact that
these seemingly simple organisms have kept their genus intact for 3500 million
years is undeniable proof of their complexity. As proof of their diversity,
about five thousand species are currently known. These species may differ in their
shape (coccus, bacillus, helical), motility (flagella, spirochetes), function,
and nutritional or metabolic diversity.
Though popular culture has lead us
to associate the term bacteria with harm, many bacteria are actually quite
useful. E. coli, a previously mentioned example, is useful in research,
but is also found in the human intestine... (Note: I am not completely done
with this paragraph yet…)
These deceptively simple creatures
have immensely complex ways of communication as well. Bacteria secrete autoinducers
(chemical signal molecules) in order to communicate. These molecules can
regulate gene expression and behavior by detecting the concentration of a
certain autoinducer. This method of communication can allow bacteria to act
like multicellular organisms. For example, on study conducted by Bonnie
Basselor and her peers…(Note: I am not completely done with this paragraph yet…)
At this point, my study of bacteria
appeared somewhat broad, so I attempted to narrow my focus from the diversity
of bacteria to developing methods of preventing harmful bacteria from entering
human systems. Previously, an antimicrobial by the name of Triclosan, or Microban
was used. Triclosan proved to be effective, but there were soon rising concerns
about the toxicity of triclosan because it is a possible carcinogen, and is
closely related to dioxin. Over the years, the use of this antimicrobial declined.
However, this brief study of
antimicrobials introduced me to another of the wonders of bacteria: triclosan
also brought up concerns because bacteria easily gained antibiotic resistance
to it. The concern that they adapted so easily, in just a few generations,
amazed me and uncovered a whole new layer of versatility in the world of
bacteria.
Please note that the above fragment is only a small part of my entire essay. The full essay is much more detailed, but I do not want to release the entire paper all at once.
Sunday, April 1, 2012
More Research
I really want to contact this professor: http://www.jhsph.edu/faculty/directory/profile/3936/Halden/Rolf_U. That would just be amazing... I could learn so much!
Other Antimicrobials
I discussed triclosan in the previous post... I also found some other substances that are associated with antimicrobial properties:
Australian tea tree oil
Grapefruit seed extract
Pine oil
Thyme oil (thymol)
H2Orange2 (a combination of hydrogen peroxide and orange oil)
Activated Triclosan (supposedly more efficient than the "traditional" version)
Australian tea tree oil
Grapefruit seed extract
Pine oil
Thyme oil (thymol)
H2Orange2 (a combination of hydrogen peroxide and orange oil)
Activated Triclosan (supposedly more efficient than the "traditional" version)
The Controversy over Triclosan
Triclosan is an antimicrobial agent used in many household antibacterial products. A controversy presides over the use of this agent, however.
First, I would like to address the issues associated with Triclosan, and its function in our bodies. Triclosan blocks the active site of the enoyl-acyl carrier protein reductase enzyme. This enzyme is an essential enzyme required for the fatty acid synthesis in bacteria, and when Triclosan is present, it acts as a competitive inhibitor for the active site. As a result, the bacteria is prevented from producing the fatty acids needed for growth and reproduction, which in turn kills the bacteria. To many, this would make Triclosan a reasonable antimicrobial agent. However, some studies show that when exposed to water and UV rays, they are transformed into a potential carcinogen, Dioxin. I will need to conduct more research on this in order to understand how this occurs.
Also, this is a mental note to remember to look up the chemical structure of Triclosan and Dioxin and compare them...
First, I would like to address the issues associated with Triclosan, and its function in our bodies. Triclosan blocks the active site of the enoyl-acyl carrier protein reductase enzyme. This enzyme is an essential enzyme required for the fatty acid synthesis in bacteria, and when Triclosan is present, it acts as a competitive inhibitor for the active site. As a result, the bacteria is prevented from producing the fatty acids needed for growth and reproduction, which in turn kills the bacteria. To many, this would make Triclosan a reasonable antimicrobial agent. However, some studies show that when exposed to water and UV rays, they are transformed into a potential carcinogen, Dioxin. I will need to conduct more research on this in order to understand how this occurs.
Also, this is a mental note to remember to look up the chemical structure of Triclosan and Dioxin and compare them...
Friday, March 16, 2012
EE Connection!
Originally, I had planned to do my Extended Essay for IB on cancer research, but I later found that it did not satisfy the Biology rubric because it was more of a Medical topic. So I am saving that research for later, and I have thought of something that I may be able to connect to my current ISP research!
Antibacterial agents
such as triclosan and plant extracts have proven to be effective in controlling
bacterial growth, but I would like to delve into this topic even further and
determine what concentrations and mixtures prove most effective, and how bacteria
react to these mixtures: do new antibacterial resistant strains develop?
I think it would be an interesting research topic, and I may post some of the sources I use for my EE on this blog.
Friday, February 10, 2012
MORE pGLO!
Here are some more pictures from the pGLO lab:
These two are also pictures of the +pGLO LB Amp/Ara.
This picture shows the -pGLO LB. Almost the entire surface of the agar is covered with bacteria.
This picture shows the -pGLO LB Amp. There is no growth-no pre-resistant strands (yay!).
This picture shows the +pGLO LB Amp. There is some growth, indicating that the transformation was successful.
These two are also pictures of the +pGLO LB Amp/Ara.
Focus
I want to create a more focused topic to research on- bacteria is a very wide topic. Any ideas?
Bacterial Transformations Continued:
Photo credit: Connie Cheng
Today in Biology, we shined UV light on the +pGLO, LB, AMP/ARA colonies. The bacteria glow in the presence of UV light, as described in the previous post.
Some more information on this lab and the arabinose operon can be found on this site (http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20101/bio%20101%20laboratory/bacterial%20transformation/bacteria.htm), which I may use for more research in the future.
Bacterial Transformations!
In biology, we are currently performing a bacterial transformation. In order to understand bacterial transformation, it is important to understand the structure of Prokaryotes and their genetic material.
The genetic material of bacteria is located in the cytoplasm, because Prokaryotic cells do not contain a nucleus. The genetic material is concentrated in one region and is referred to as the nucleoid. However, the cell also contains important genetic information for the growth of bacteria on circular pieces of double-helix DNA called plasmids. These plasmids can replicate independently of the bacterial DNA. Bacteria can transfer these plasmids between one another, and the plasmids can be used to provide resistance to antibiotics, and in genetic engineering.
Plasmids can be used to make an organisms express a particular gene. Plasmids can be inserted into bacteria in a process called transformation.
In the lab we are doing, we will have four plates: -pGLO LB, -pGLO LB Amp, +pGLO LB Amp, and +pGLO LB Amp/Ara. LB is lysogeny broth, which is a nutrient-rich medium that is commonly used for bacterial growth. pGLO is the plasmid that will be inserted into the E. Coli bacteria. The -pGLO plates will not glow, and will be used as our controls. However, only the -pGLO LB will show normal growth. The -pGLO plate with Ampicillin will not show any growth. Ampicillin is a type of bacteria that will inhibit the growth of E. Coli, so if the E. Coli does create colonies, it means that they are already resistant to Ampicillin without the pGLO plasmid. The +pGLO plate with Ampicillin but no Arabinose will not glow (because the Arabinose is one environmental factor that leads to the glowing E. Coli), but will have some colonial growth if the transformation was successful. If there is colonial growth, the transformation is successful because the E. Coli has resistance to the Ampicillin bacteria. The +pGLO with both Ampicillin and Arabinose will glow in UV light, because the Arabinose turns the gene for GFP (Green Florescent Protein) on, and the bacteria transcribes the DNA to make the protein GFP. This protein glows in UV light because the electrons in the protein are excited by the light and jump up to the next highest level in the electron cloud, emitting energy in the form of light.
We have set up the plates, and we will let them grow until next block (about two days). On Friday, we will look at them under UV light.
The genetic material of bacteria is located in the cytoplasm, because Prokaryotic cells do not contain a nucleus. The genetic material is concentrated in one region and is referred to as the nucleoid. However, the cell also contains important genetic information for the growth of bacteria on circular pieces of double-helix DNA called plasmids. These plasmids can replicate independently of the bacterial DNA. Bacteria can transfer these plasmids between one another, and the plasmids can be used to provide resistance to antibiotics, and in genetic engineering.
Plasmids can be used to make an organisms express a particular gene. Plasmids can be inserted into bacteria in a process called transformation.
In the lab we are doing, we will have four plates: -pGLO LB, -pGLO LB Amp, +pGLO LB Amp, and +pGLO LB Amp/Ara. LB is lysogeny broth, which is a nutrient-rich medium that is commonly used for bacterial growth. pGLO is the plasmid that will be inserted into the E. Coli bacteria. The -pGLO plates will not glow, and will be used as our controls. However, only the -pGLO LB will show normal growth. The -pGLO plate with Ampicillin will not show any growth. Ampicillin is a type of bacteria that will inhibit the growth of E. Coli, so if the E. Coli does create colonies, it means that they are already resistant to Ampicillin without the pGLO plasmid. The +pGLO plate with Ampicillin but no Arabinose will not glow (because the Arabinose is one environmental factor that leads to the glowing E. Coli), but will have some colonial growth if the transformation was successful. If there is colonial growth, the transformation is successful because the E. Coli has resistance to the Ampicillin bacteria. The +pGLO with both Ampicillin and Arabinose will glow in UV light, because the Arabinose turns the gene for GFP (Green Florescent Protein) on, and the bacteria transcribes the DNA to make the protein GFP. This protein glows in UV light because the electrons in the protein are excited by the light and jump up to the next highest level in the electron cloud, emitting energy in the form of light.
We have set up the plates, and we will let them grow until next block (about two days). On Friday, we will look at them under UV light.
Kary Mullis
This is a Ted Talk I watched recently. It is about curing bacterial diseases using a molecule called alpha-gal epitope, which our bodies are immune to. I found his finding very interesting.
The speaker, Kary Mullis, expanded his theory for a cure after he watched a friend who died even though he was using powerful antibiotics.
A further reflection on the video will be made in a later post.
This is a Ted Talk I watched recently. It is about curing bacterial diseases using a molecule called alpha-gal epitope, which our bodies are immune to. I found his finding very interesting.
The speaker, Kary Mullis, expanded his theory for a cure after he watched a friend who died even though he was using powerful antibiotics.
A further reflection on the video will be made in a later post.
Sunday, January 8, 2012
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