Micro Exam 3: Examples of Symbiosis Biofilms and Microbiome

Consortium/a

Freshwater microbial mutualisms. They consists of green sulfur bacteria and a flagellated rod-shaped bacterium. This gives a genus species name.

Describe the normal microbiota and the purposes its serve in the environment and human populations

Normal microbiota is important because it does make us healthier, but when the normal flora is altered it may lead to different infections and is a main cause of infections dealing with the slight change in pH or availability of nutrients can be dangerous.

Secondary

Not required for reproduction. Not always present in every individual. Can invade different cells and live extracellularly. MUST provide a benefit of some sort.

Parasitism

One member in the relationship benefits while the other is harmed

Commensalism

One species benefits and the other is neither harmed nor helped

Explain why biofilms are a concern in medicine.

Organisms on the surface of a biofilm can be difficult to break apart due to the presence of an extracellular matrix, which means antimicrobials are often not as effective. Another issue is the organisms embedded within the biofilm are protected from antimicrobial exposure, so they are especially well protected and capable of surviving an antimicrobial treatment. This also means it is also very difficult for an immune system to rid of a biofilm. These types of infection are typically then chronic infections and depending on the particular infectious agents could eventually lead to removal of the entire infected tissue or death.

Primary Symbiont

Required for host reproduction and restricted to bacteriome.

Look at all different essays we had to write summaries for!

SERIOUSLY

Microbiome

Sites of microorganisms

Symbiosis is an interaction between two different organisms living in close physical association, how could this relationship affect the microenvironment of an organism?

Symbiosis can reduce the amount of competition for food in an environment through mutualism where both organisms will benefit from one another or commensalism where one organism benefits from the environment while the other is not affected. It may also harm the environment through parasitism where one organism benefits at the other's loss

Probiotic

Live microbes applied to or ingested into the body, intended to exert a beneficial effect

Symbioses

Many microbes establish relationships with other organisms

Symbiont

Either of two organisms that live in symbiosis with one another.

Give examples of and explain symbiosis between microorganisms and plants, insects, invertebrates, and mammals

1) Algae-fungus mutualistic: Alga produces organic matter for fungus and fungus provides a way in which alga can grow protected from erosion. 2) Legumes-plants mutualistic: Nitrogen fixing bacteria grow within root nodules that are infected, but creates an increase in nitrogen in the soil. 3) Endo/ectomycorrhizae: Protect roots by forming a layer around them or in them 4) Parasites, E.Coli

Explain the role of biofilms in chronic diseases/infections

65% of all human infections are probably related to biofilms. Biofilms prevent penetrations from any antimicrobial agent or antibiotic so they are very well protected from any treatment thrown at them. It's also very hard for the immune system to rid them. They are seen in kidney stones, tuberculosis, and periodontal disease.

Predict conditions that would favor biofilm formation and where they might be found

A surface that is relatively rough will attract microbes because a flat surface may be able to be washed away more easily. They also attach more readily to hydrophobic surfaces. Bacteria with flagella also form biofilms more readily

Compare and contrast commensal, symbiotic, and pathogenic relationships

A symbiotic relationship is when one organism can survive in the present of another organism. Commensalism is a type of symbiotic relationship where one organism benefits and the other is not affected. A pathogenic relationship is also a type of symbiotic relationship, but an organism causes damage to the host it's living with or in.

Biofilm

Assemblages of bacterial cells adhered to a surface and enclosed in an adhesive matrix excreted by the cells. They trap nutrients for microbial growth and help prevent detachment of cells in flowing systems

Explain how and why biofilm development may differ in different environments

Biofilms are different in different environments because it depends on what nutrients are available in that specific microbiome and what type of surfaces they form on.

Mutualism

Both species benefit

Prebiotic

Chemicals that enhance growth of normal microbiota

Vertical Transmission

Comes from parents

Microbial Anatagonism

Competition between microbes

Horizontal Transmission

Environmental Reservoir

Explain what adaptions are necessary for a bacterium to survive in the respiratory tract, skin, intestinal tract, urinary tract

Intestinal Tract: must produce enzymes, and amino acids and be able to live in more acidic environments. Skin: Chemical composition and moisture play a big role. Depends on the hygiene of the person and environmental factors. Respiratory: Be aerobic Urinary: Live in sterile conditions with little nutrients. Female deals with slight acidity due to pH

Quorum Sensing

Intracellular communication. It is critical in the development and maintenance of a biofilm

Predict the effect on a host organism if the normal microbiota were removed

It can potentially form infections and other problems because it's more prone to them. Acidification or acidosis is one consequence of changing the microbiome.

Lichens

Leafy or encrusting microbial symbioses. Often found growing on bare rocks, tree trunks, house roofs, and the surfaces of bare soils.

Describe how the human microbiome influences the host human organism

The human microbiome describes who we are and what we eat and can digest. It has developed greatly over millions of years adjusting different diets and keeping us healthy.

Microbial Mats

Very thick biofilms and are built by phototrophic and/or chemolithotrophic bacteria.

Identify stages of biofilm development that are more susceptible to destruction

When the biofilm is in the development stage, it is the hardest to rid, and can only change in shape and size, and if it continues to multiply can cause major damage. In the attachment phase, only some bacteria cells are attached together and is the easiest to destroy.

Compare and contrast cell structure and function in a biofilm

Within a biofilm, bacterial cells are adhered to a surface and enclosed in an adhesive matrix. Biofilms trap nutrients for the growth of microbes and prevent detachment. They form to allow bacteria cells to live in close association with one another and the resist physical forces that may sweep away unattached cells and other items.

Two organisms that both benefit from each other are in a symbiotic relationship called a. Mutualism b. Commensalism c. Parasitism d. Ammensalism

a. Mutualism

Lichens are a mutualistic association of a fungus and either an alga or a cyanobacterium in which a. The fungus protects the photosynthetic partner from erosion b. The fungus slowly engulfs the photosynthetic partner c. The fungus helps collect sunlight for the photosynthetic partner d. The phototroph provides phosphorus to the fungus

a. The fungus protects the photosynthetic partner from erosion

The microbiome contains all a. Organisms within the digestive system b. Organisms present in and on the body c. Organisms present on the skin and in the digestive system d. Organisms present on the skin

b. Organisms present in and on the body

Following antibiotic therapy, patients are often administered ________ to facilitate recolonization of normal flora. a. Antivirals b. Iron c. Probiotics d. Fluoride

c. Probiotics

Plant root nodules are a. Harmful to plants because the bacteria outcompete the pants of nutrients b. Formed from gall-rotting bacteria that decompose plant roots c. Structures created by fungi and are found in all agricultural crops d. Sites where nitrogen fixation occurs

d. Sites where nitrogen fixation occurs

Which of the following is NOT true of human gut microbes? a. They are involved in the 'maturing' of the gastrointestinal tract b. They help catabolize polysaccharides c. They produce and excrete amino acids d. The population size is low, but diversity is high

d. The population size is low, but diversity is high