Microbiology MOOC Newsletters

Student Timeline

2015-03-23T10:37:00.002-07:00

Daily Newsletter April 19, 2012

2012-04-19T16:20:00.001-07:00

Daily Newsletter April 19, 2012

Today's Topic: Tuberculosis

Readings:
Tuberculosis
CDC Website for Tuberculosis. Check out some of the links to learn more about Tuberculosis.
Mycobacterium Tuberculosis
Mycobacterium tuberculosis and Tuberculosis

Tuberculosis is a disease that is still endemic (always present). It is also one of the most highly contagious disease. The infectious does can be a low as one bacterium making it all the way to an aveolus in the lung. Because it is so infectious and contagious, it is a disease that medical personel take very seiously.

Daily Challenge: Write about Mycobacterium tuberculosis and the disease Tuberculosis. One challenge with the organism is that the human body has a hard time eliminating it, so you may want to look into why it is so hard for the body to eliminate.

Daily Newsletter April 18, 2012

2012-04-18T15:16:00.001-07:00

Daily Newsletter April 18, 2012

Today's Topic: Neisseria gonorrhoeae

Suggested Reading:
Gonorrhea - CDC Fact Sheet
Pelvic Inflammatory Disease (PID)
Gonorrhea Laboratory Information: Characteristics of N. gonorrhoeae and Related Species of Human Origin
Gonorrhoea (Neisseria gonorrhoeae) in the United States

Daily Challenge: Neisseria gonorrhoeae
Write about Neisseria gonorrhoeae. Discuss the organism, the diseases it causes, and how it can reinfect the same host.

Daily Newsletter April 17, 2012

2012-04-17T07:04:00.000-07:00

Daily Newsletter April 17, 2012

Daily Topic: Nosicomial Infections (specifically Staphyloccocus aureus)

Nosicomial refers to infections that are acquired in health-care environments.
Suggested Readings:

Healthcare-associated Infections (HAI)

CDC website on HAI or NOsicomial Infections. This is a good start point for your readings.

HAIs: The Burden
Staphylococcus aureus in Healthcare Settings
Methicillin-resistant Staphylococcus aureus (MRSA)
Vancomycin-intermediate Staphylococcus aureus and Vancomycin-resistant Staphylococcus aureus

Daily Challenge: Discuss the concept of nosicomial infections and specifically the diseases that can be caused by hospital acquired Staphylococcus aureus. Relate this to the concepts of microbial control, and why it is important to practice medicine underdisinfected and/or sterilized condition.

2012-04-16T09:35:00.001-07:00

Daily Newsletter April 16, 2012

Special Announcement: All blogs this week are worth 6pts. They must be uploaded by Sunday April 22.

Today's Topic: Flu

Reading: Seasonal Flu: The Basics
This is a CDC website on the flu. Browse the topics and read about the flu.

Genetics of the Influenza Virus
A good short article on influenza genetics and why it is constantly changing.

Daily Challenge: Flu
Write about the flu. Discuss the different aspects including signs and symptoms (what are signs and what are symptoms?). Discuss the changes in the flu virus from a genetics perspective, and look at public health concerns.

Daily Newsletter April 13, 2012

2012-04-13T05:55:00.001-07:00

Daily Newsletter April 13, 2012

Daily Challenge: Your Take What is your take on Environmental and Industrial Microbiology? What are you taking away from this week's topic? What have you learned about applied and environmental microbiology?

2012-04-12T06:27:00.001-07:00

Daily Newsletter April 12, 2012

Today's Topic: Environmental Justice

Readings: The following readings support your daily challenge dealing with Environmental Justice. These are all short readings to get you started.

Daily Challenge: Environmental Justice
In your own words, describe the concept of Environmental Justice. How could a microbiologist play a role in environmental justice discussions? How could environmental injustice affect public health?

2012-04-11T10:56:00.000-07:00

Daily Newsletter April 11, 2012

Today's Topic: Looking for novel pathways

As discussed today, one microbial endeavor is to discover novel metabolic pathways or products that have applications in the modern world. Here are three research areas influenced by looking for novel pathways (even multispecies pathways).

metabolic engineering

We've talked a little about this previously.

metabolic network analysis

This is looking at the overall metabolic pathways of an organism or a system of organisms, including looking at the relative activities of different pathways.

metabolic network reconstruction

As the name implies, this is dealing with reconstructing the entire metabolic network of organisms and even assemblages of organisms.

The idea here is to learn about the metabolic capabilities of an organism (at various conditions) or a community/assemblage of organisms. With this information, researches can maximize a system or even engineer new systems. But you first must find the systems? That is the million dollar question. Some times it is by accident. Other times it is the product of specific experimental design. Organisms that degrade oil were "discovered" when people started looking in areas with native oil deposits, and then tried to isolate organisms that grew on specific oil products.

Currently known organisms could also have novel pathways. Genomics, Proteomics and Metabolomics can all help find novel pathways. What is important first is that you start looking.

Daily Challenge:
Discuss the importance of new metabolic pathways and products. Look up some of the recent discoveries. Why is it important that we look for novel pathways? What effect could these have on medicine, industry, or even society?

Daily Newsletter April 10, 2012

2012-04-10T10:45:00.000-07:00

Daily Newsletter April 10, 2012

Today's Topic: Industrial Fermentation

Reading:

Fermentation Technology Abstract

This abstract, written by Enzymm: Project Consulting for Life Sciences, is an excellent primer for industrial fermentation. The PDF is 15 pages, but over all the text is rather short. You will see references to topics we discussed in bacterial growth.

Industrial fermentation's origin can be found in fermented food. Cheese making, vinting (wine making), brewing (beer making), and even making kimchi or sauerkraut are accomplished through fermentation.

As microbiologists, you have two uses of the word fermentation.

1) Fermentation defined as a form of anaerobic respiration in which pyruvate is reduced to an end product such as ethanol or lactic acid.

2) The growth of large numbers of bacterial or fungal (yeast) cells in order to produce a useful product (enzymes, vitamins, antibiotics, or whole cells).

- This second definition came from the growth of yeasts to high concentration in order to produce ethanol as an end product (beer, liquor, wine). In modern uses, the end product of pyruvate reduction is not the only valuable end product. In industrial fermentation, you don't even have to have anaerobic metabolic pathways; the cells could be using oxygen for aerobic respiration. The goal though is to get a useful product out of the microbial growth.

Daily Challenge: Your take on fermentation
Using the above reading, your textbook, and any references you find, discuss the idea of industrial fermentation. First give a general overview of what is meant by industrial overview. Look for some topic that interests you, something that you would like to know more about. Write a quick paragraph about it. Industrial fermentation is a broad topic, and one in which whole classes are devoted, so just look for some aspect that interests you.

2012-04-09T13:40:00.001-07:00

Daily Newsletter April 9, 2012

Today's Topic: Introduction to Applied and Environmental Microbiology

Microbiology touches all of our lives. We are most familiar with diseases caused by microorganisms, but they are important to other aspects of our life. This also means that there are many career opportunities for people interested in microbiology. Here are a few of the topics that we are going to look at this week:

Industrial product formation using microorganisms.

Supplements such as yeast extract or whey protein.
Biotransformed compounds such as steroids.
Enzymes such as Glucose Isomerase.
Antibiotics such as penicillin and streptomycin.
Food additives such as agar and vinegar.
Alcohol such as ethanol (beer, wine, distilled spirits).
Chemicals such as citric acid.
Processes include Fermenation and Product Purification.

Bioremediation

Removal of chemical pollutants using biological (metabolic) means.

Biotechnology

Gene engineering for hormone production.
Recombinant Vaccines.
DNA vaccines.
Metabolic Engineering.
Transgenic Plants (using bacterial genes in plants).

Sterilization and Decontamination

Including Pasteruization
Radiation decontamination of food.

Food Preservation and Food Production

Various

Microbial Communities

Agricultural Microbiology.
Marine Microbiology.

Microbial Ecosystem Studies

Nutrient Cycling
Biofilm production

Symbiosis among microorganisms.

Above is just a simple list of the various aspects of Applied and Environmental Microbiology.

Daily Challenge: What interests you in Applied and Environmental Microbiology?
Write about some aspect of applied and environmental biology that interests you (not medical). If you want, take a topic from the above list and do a little research about it. What jobs are available? You can go to asm.org (American Society for Microbiology) to look up job listings. This is an opportunity to explore the opportunties of microbiology.

Daily Newsletter April 5, 2012

2012-04-06T07:10:00.000-07:00

Daily Newsletter April 5, 2012

Today's Topic: Proviral Genes

Read the following article: Effects of Proviral Integration on Host Gene Expression

It is estimated that 8-10% of human genes are actually viral in origin. These viral genes provide for a number of important physiological responses. One of the most important proviral impacts in mammals is the formation and function of the placenta.

Read the following short article: Proviral protein provides placental function

Daily Challenge:
In your own words, describe how proviruses have impacted human physiology and evolution.

Daily Newsletter April 5, 2012

2012-04-05T09:12:00.000-07:00

Daily Newsletter April 5, 2012

Today's Topic: Influenza

Suggested Reading:

Below are links to a series of short articles on the flu and the influenza viruses. Please read over these articles, as they will help you with today's challenge.

Here is a longer article on Influenza Life Cycle that would also be helpful.

As discussed in class, one of the critical factors in a viral cycle is the attachment of the virus to the host cell. In the above diagram, you can see the basic stages of Influenza A. Attachment, leading to endocytosis. Uncoating occurs, followed by the viral genome taking over cellular metabolism for the formation of new viral particles. Finally, the budding of new viral particles.

The image below is another example of the influenza life cycle, but in this diagram, note the formation of the viral spikes in the endoplasmic reticulum and Golgi apparatus.

Make note of the formation and incorporation of viral spikes.

Daily Challenge:
In your own words, describe the Influenza viral "life" cycle. Discuss how the spikes are variable, and how the flu changes from year to year. Discuss the concept of antigenic drift and antigenic shift as it applies to the alterations in the flu and vaccination protocols.

Daily Newsletter April 4, 2012

2012-04-04T09:18:00.000-07:00

Daily Newsletter April 4, 2012

Today's Challenge: Bacteriophage (Viruses of Bacteria) Using your textbook, online resources, and notes from class, describe the lytic and lysogenic cycles.

Supplemental Resources:
Virus Lysogenic & Lytic Cycle Video

Prokaryotic Transduction

The Origin of Viruses - A good overview of viral evolution.

Daily Newsletter April 2, 2012

2012-04-02T11:53:00.000-07:00

Daily Newsletter April 2, 2012

Today's Topic: Introduction to Virology
Suggested Reading: Viral Structure

What is a virus?

Viruses are biological agents that need a host cell in order to carry out standard biological process such as metabolism and replication.

We typically think of viruses in terms of diseases: Flu, colds, HIV, herpes, etc...

Daily Challenge: Viruses Your task today is to reflect on viruses. The goal is not to talk about the specifics of viruses, but to discuss the importance of viruses to the world.

Daily Newsletter March 30, 2012

2012-03-30T07:11:00.000-07:00

Daily Newsletter March 30, 2012

Daily Challenge: Eukaryotic Microbes and Humanity

In our continued discussion of the Eukaryotic Microbes, today you are to discuss the relationship of Eukaryotic Microbes to Humanity.

This is an open-ended challenge. You could talk about the environment, diseases, evolution, industry, or just about anything as long as it deals with the interaction between Humanity and Eukaryotic Microbes.

The goal of this is for you to explore this complex and diverse grouping of organisms and find those items that fascinate or inspire you. Your not expected to write about EVERYTHING, just about what you find as fun.

Daily Newsletter March 29, 2012

2012-03-29T09:57:00.002-07:00

Daily Newsletter March 29, 2012

Today's Topic: Protozoa
Suggested Reading: Introduction to Protozoology

The Kingdom Protista (Protoktista) is currently undergoing massive restructuring based upon genetic analysis. New classification schemes are being proposed and debated. These schemes break up the algae (protophyta) into different phylla, and even rearrange some families and genera. The same is occurring for the non-photosynthetic unicellular eukaryotes commonly referred to as the Protozoa ('proto' meaning earliest form of, and 'zoa' meaning animal).

The award winning evolutionary biologist Thomas Cavalier-Smith has been at the forefront of the changes in taxonomic structure for over twenty years. His reclassification of the protozoa is now well regarded among parasitologists and evolutionary biologists. Below is a 'Tree of Life' commonly used by parasitologists, and is based on the work of Cavalier-Smith.

Note that animals, plants and fungi are reclassified as Kingdom Opisthokont. This is due to the idea that animals, plants and fungi have genetic and metabolic commonalities that separate them from all other life (they are a monophyletic group).

Do you see how the genetic revolution has altered our appreciation of the diversity of life?

Why is it important for scientists to create a tree of life that is really based on genetic and metabolic relatedness?

While it is critical to recognize that the classification of protists is being rethought, it is important to understand some of the main protozoal groups. The proposed kingdoms most linked to Protozoa are:

Rhizaria
Excavata
Amoebozoa
Aveolates (not listed in above chart)

Daily Challenge:Take one of these protozoal groups and write about them. What are some of the species now held in this new grouping? Why are they now being considered related to each other, but different from other protists? Are there any species that are relevant to medicine, industry, food?

Daily Newsletter March 28, 2012

2012-03-28T13:11:00.001-07:00

Daily Newsletter March 28, 2012

Today's Topic: Fungi
Suggested Readings: Doctor Fungi (a great site for general medical mycology).
The Web of Life: Fungi (Good general introduction).

I like fungi. Their fun, do some amazing things, and perform critical function in our ecosystems. They also tend to be the least discussed in biology classes. Why? Few people work on them. They are not as high profile as viruses, or not as well known as the pathogenic bacteria. Save for the fungi used in food, we usually think of fungi in a negative light (you have mold! Kill it, Kill it, Kill it).

Fungi though have been the work horse of genetics, and yeast has been used for baking and brewing for thousands of years. So what is so interesting? Here is a small list:

Ascospores can be used to demonstrate meiosis, and provides a great visual of Mendelian genetic at work.
Fungi are great models of eukaryotic genetics and molecular processes.
Most of our antibiotics are derived from Fungi.
Fungi can be used to fight insects (biocontrol)

Some fungi can even lasso nematodes in the soil (the purpose is to acquire nitrogen)
http://youtu.be/0n04wCkIpuQ

Fungi are used as food and to prepare food.
Some fungi spoil food (bread mold)
Fungi are even now being used as replacements of Styrofoam: http://green.blogs.nytimes.com/2009/04/13/using-fungi-to-replace-styrofoam/
They are decomposers (natural and use in industrial settings).
Mycorrhizal fungi help plants to grow.
Some fungi are plant pathogens.
Pathogenic Fungi of animals and mycotoxins.

Daily Challenge: Pick one topic about fungi, and write about it.

Daily Newsletter March 27, 2012

2012-03-27T09:03:00.001-07:00

Daily Newsletter March 27, 2012

Today's Topic: Harmful Algal Blooms

Algae inhabit many areas of the world. There are marine and freshwater algae, soil algae, and those that form symbiotic relationships to produce lichens. All algae have photosynthetic capabilities, which means that they are primary producers (first level of a food chain), and are oxygenic (produce oxygen).

There are secondary metabolites that algae can produce, for example the Rhodophyta (Red Algae) produce Agar. This gelatinous substance is used for microbiological media, and in cooking. As a culinary agent, it is used as a substitute for pectin to produce jellies, jello, and other gelatinous confections. It is also used as a gelling agent in ice cream. (What is the chemical structure(s) of Agar?)

Not all phytoplankton secondary metabolites are so useful or desirable. Some algae produce toxins, most often neurotoxins. At low concentration levels, they are of minimal risk. The problem is that they can bioaccumulate in marine organisms, most notably shellfish.

The diatom Nitzschia navis-varingica produces the toxin domoic acid, which in high doses, causes permanent loss of short term memory and brain damage. Death is a possible outcome with high concentrations of the toxin.
The dinoflagellate Alexandrium fundyense produces saxitoxin, the toxin responsible for paralytic shellfish poisoning (PSP). PSP has multiple symptoms, that usually start with abdominal cramps and diarrhea, but progress to mental functions and loss of coordination. As the name implies, paralysis is an advanced symptom.
Karenia brevis, a dionflagellat, produces brevetoxin, which causes neurotoxic shellfish poisoning (NSP). NSP has no reported fatalities, unlike the previous two toxin based diseases, but can cause painful abdominal problems, slurred speech, and other neurological problems.

Harmful algal blooms are often reffered to as Red Tide, a phenomena where the algal population is so large that it becomes visible on the surface of marine environments. Red Tides can be beautiful, but harmful algal blooms are not always red. The blooms also don't follow tides, they generally stay in an area (the cells produce a film that congeals them).

Daily Challenge: Pick one of the harmful algal blooms above and discuss it in more detail. Describe the algae and it's habitat. When and why would the algae experience a bloom? Describe the toxin, and the affect it has on human phisiology. Why doesn't the toxin affect shell fish? Describe the signs and symptoms of the disease condition (signs are observable, while symptoms are personal to the patient; e.g., patient core temperature or blood pressure is a sign, nausea or a feeling of unease is a symptom).

Daily Newsletter March 26, 2012

2012-03-26T16:44:00.000-07:00

Daily Newsletter March 26, 2012

This week's topic: Eukaryotic Microbiology

When we talk about microbiology, most peoples thoughs immediately turn to bacteria and viruses. There are though a number of Eukaryotic microbes. It is important to remember that microbiology is ultimately the study of organisms too small to see with the naked eye.

Why then do we spend so much time on bacteria? The answer is rather simple. Most of your training has been on eukaryotic cells. Principles of Biology, as well as Cell and Molecular Biology, focus on eukaryotic systems. As you have seen, bacterial and archaeal systems are different. We need time to go through those differences, and also talk about the importance and impact of these other two domains of life.
Are Eukaryotic Microbes as important as bacteria? YES!

Phytoplankton, which is made up of both photosynthetic bacteria and algae (photosynthetic microscopic eukaryotes) produce most of the world's oxygen.
Fungi are important decomposers, and are needed to recycle nutrients in the environment.
The mycorrhizal fungi are needed for the healthy growth of many plants.
Yeasts are needed in bread making and brewing.
Protists (microscopic animal-like eukaryotes) are important predators of other microbes.
Protists are also medically important.

Daily Challenge: Common Characteristics
When doing taxonomy, it is important to have a clear idea about the common characteristics that seperates one group from another. To that end, you are to compile a list of common characteristics for the Algae, Protists and Fungi. Make sure you discuss these characteristics! Questions to start you off:

Is the organism heterotrophis or autotrophic?
Is the organism predatory or a detritivore?
What is the organization of the cell?
Does the cell have a cell wall, and if so, what is it made of?
Any special cellular characteristics, such as unique lipids in the membrane?
Any special metabolic features?
Remember Alternation of Generations? How would you classify the organism?
How does the organism reproduce?
Are there any important reproductive structures or strategies common to the group?

Daily Newsletter March 23, 2012

2012-03-23T17:17:00.000-07:00

Daily Newsletter March 23, 2012

Daily Challenge: Archaea
Pick one Archaea that you find interesting, and write about it. Write up a "personal profile" of the organism. Beyond the basics of taxonomy and habitat, highlight the special features of the cell.

Summer Course:
BIOL 4930, CRN 53934, is a topics class with a focus on Medical Mycology. The instructor, Dr. Errol Reiss, is retired from the CDC and is a mycologist of note. As we have few classes that focus on Fungi, I would strongly suggest that you take this opportunity to learn some of the medical implications of Fungi.

Daily Newsletter March 22, 2012

2012-03-22T10:02:00.000-07:00

Daily Newsletter March 22, 2012

Daily Challenge: As with bacterial diversity, archaeal diversity is best handled by looking over the organisms. Today I would like you to review and write about the Methanogens. Describe their taxonomy, habitat, and metabolic features. Include a discussion methane production.

Daily Newsletter March 21, 2012

2012-03-21T04:28:00.000-07:00

Daily Newsletter March 21, 2012

Today's Topic: Archaea

The Archaea represent the third domain of life, and as such posses characteristics that make them different from either Bacteria or Eukarya. They are prokaryotic, but with some unique features. Your goal today is to learn what makes Archaea different from Bacteria.

You may have heard in the past that Archaea are extremophiles, living only in extreme environments. This is a lovely fiction. While many Archaea live in extreme environments, it is not a requirement. Some even live in moderate environments. So what then makes them different?

First, they are prokaryote, which makes them different from Eukarya (there is more than just this, but let's wait for a moment). Like Bacteria, they have cell walls, but their cell walls are not based on peptidoglycan. Instead, the Archaea form an S-Layer to act as the cell wall.

The Archaea produce transmembranal proteins to create a schaffold for globular proteins. These globular proteins are then arraied to form a protective coating similar to "chain mail" (see the image below). Some Archaea, such as members of the Order Methanobacteriales add pseudomurein to add additional support and strength to their cell walls. Pseudomurein is similar to peptidoglycan, but lacks the ordered arrangement of glycan chains.

Another major difference between the Archaea and both the Eukarya and Bacteria is in the formation of their cell membranes. You will recall discussions of phospholipids and cell membranes. You may remember that we always discuss phospholipids as having ester linkages between fatty acids and the gylcerol backbone. This is not the case with Archaea. Archaea use an ether linkage between fatty acids and the glycerol backbone. In addition, archaeal fatty acids can be connected across the membrane, resulting in monolayers (instead of bilayers). A molecule with two polar heads seperated by a non-polar region is known as a bolaamphiphile.

Consider the Archaeal phospholipid: What advantage would an ether linkage provide? What advantage would a bolaamphiphile provide? Would you make these the same way you would make a bacterial phosophlipid? What type of metabolic pathways would you have to have? Based on this physiological difference, can you compare the evolutionary history of these two organisms?

You will also note in the above diagram that the fatty acids are also different. Archaeal fatty acids are based on isoprenoids and they can have cyclopropane and cyclohexane ring structures. While there are other differences to Archaeal phospholipids, digest on what we have mentioned for now. One thing to note: while the chemical architecture may be different, Archaeal phospholipids serve the same function as other phospholipids, and their membranes have the same function as other cellular membranes.

Unlike Bacteria, but like Eukarya, Archaea use Methionine on the initator tRNA. There are also some structural differences between the Archaeal tRNA, and those found in Bacteria and Eukarya. As with bacteria, Archaea lack introns, and do not undergo splicing.

They have 70S ribosomes, but their ribsomes are different enough from Bacteria that the ribosome effecting antibiotic chlramphenicol does not affect Archeal ribosomes. Conversely, the Eukaryotic ribosomal toxin anisomycin also affects Archaeal ribosomes. So while they are bacterial in size, they so similarities to the Eukaryotic ribosome.

Another anomylous protein is DNA-dependent RNA polymerase (RNA polymerase that makes mRNA). While it is a single enzyme, like Bacteria, it is a complex protein that more closely resembles the subunit patterns of Eukaryotic DNA-Dependent RNA Polymerase. Also, the antibacterial compound Rifampicin, which blocks mRNA transcription in bacteria, does not work on either Archaea or Eukarya. Arhaea also have RNA polymerase II type promoters, just like Eukarya.

Archaea are neither Bacterial or Eukaryal, but they share some characteristics. They also have some unique characteristics.

Archaea have a single circular genophore (molecule of DNA), just like Bacteria. They also have a process analogous to conjugation for horizontal gene transfer. It has been shown though that Archaea possess histones, and while they don't function just like Eukaryal histones, they share a common ancestry.

Daily Challenge: Archaeal Characteristics
In your own words, describe the general characteristics of the Archaea. It has been hypothesized in the past that the Archaea are related to the Proto-Eukaryotic cell. What is your view on that with what you have read? Justify your answer.

Daily Newsletter March 20, 2012

2012-03-20T12:26:00.000-07:00

Daily Newsletter March 20, 2012

Daily Challenge: Bacterial Diversity

Today, there are four bacteria for you to look at:

Genus Bdellovibrio
Genus Agrobacterium
Genus Rickettsia or Wolbachia
Genus Anabaena

The task today is to discuss the special features of these organisms. As you will note, I'm only asking you to look at the special features of the Genus level (not individual species). Review them, and think about how this may influence our understanding of microbiology, biology in general, or biotechnology.

Special Announcement:

It's Spring Today!

Daily Newsletter March 19, 2012

2012-03-19T10:16:00.000-07:00

Daily Newsletter March 19, 2012

Special Video: In honor of St. Patrick's Day, here is a little biology video. Can you describe all of the biological processes the singer presents? Could you describe all of these if asked?

Today's Topic: Diversity

After our discussion on bacterial evolution, it is time to turn our attention to the wealth of bacterial diversity found on Earth. As you are hopefully starting to see, there are more bacteria on Earth than any other life form. Even a human being is 10 times more bacterial than eukaryotic. Many bacteria have unique biochemical pathways and interesting metabolic processes. The metabolic diversity of bacteria is incredible, with bacteria and archaea being able to perform chemical processes that do not occur in eukaryotes. Some of these chemical transformations scientists believed only humans could manage in a lab.

The only way to learn about bacteria diversity is to start learning about the different organisms. Today and tomorrow will be fairly straight forward. I want you to discuss bacteria. On Wednesday, we'll move to Archaea.

Daily Challenge: Diversity
Below, you will see three groups of organisms. Pick one organism from each group and write up a synopsis of the bacteria.

Important Information:

Taxonomy.
Habitat.
Human Interaction (Medical, Environmental, Research, Industrial)
One important metabolic feature.

Group 1: Purple Phototrophic Bacteria, Nitrifying Bacteria, Sulfur Oxidizing bacteria, Iron Oxidizing bacteria, or Methanotrophs.

Group 2: Neisseria, Vibrio, Shigella or Mycobacterium

Gropu 3: Bacillus, Streptococcus, Streptomyces, or Flavobacterium

Administrative NOTE: Milestone Paper 2
You have until tomorrow night to finish your paper reviews. Authors can then go back and leave comments for their reviewers.

Daily Newsletter March 16, 2012

2012-03-16T06:52:00.000-07:00

Daily Newsletter March 16, 2012

Today's Topic: Bacterial Evolution
As we have discussed this week, bacterial evolution is slightly different from Eukaryotic evolution. Natural selection is the same; what changes is the inheritance patterns. Hardy-Weinberg equilibrium (equation)does not hold for haploid organisms, and we can not follow inheritance through Mendelian genetics.

So, how does it compare to Eukaryotic evolution? Can we use information from bacterial evolution to inform eukaryotic evolution? The answer is YES.

Bacteria are a simple system to use in labs. The genome is smaller than eukaryote, and they grow faster. This means faster replication. As you may remember, the greatest risk of mutation is in the replication event. Outside of replication, you mutate only due to chemical or extreme environmental conditions. Replication errors are the main source of mutation. So why is mutation important? It is the foundation for all variation (allelic variation within a gene).

First off, as the article demonstrates, we can use bacterial models to show us how a beneficial mutation arises, and how long it takes for such a mutation to occur. It takes a sequence of multiple mutations to make a beneficial variation, and most of the time the mutations just lead to neutral results. There is also the loss of individuals who had negative mutations. In therms of time frame, we are looking at 10's of thousands of generations. Can this be compared to mutation rates in eukaryotic cells? Yes. It helps us to understand how we get radical phenotypic variations among individuals of a population or species.

Second, we can use bacteria as models for genomic comparisons. Looking for similarities and differences in a genome is laborious, but can be done. Using a simple system, such as bacteria, allows researchers to test procedures and hypotheses, as well as building algorithms to run the mathematical comparisons. In other words, we can create research systems in bacteria that we could transfer to studying eukaryotic genomes.

Take some time and look around the internet. Look at bacterial evolutionary studies. What do you find? What interests you? Provide references for what you find interesting, and talk about it. Ultimately, your question is: How do studies in bacterial evolution inform our understanding of bacteria?