#6 Symbiosis

Module 6-Symbiosis

Overveiw http://www.youtube.com/watch?v=D1aRSeT-mQE

Core Concepts
Symbiosis- unrelated organisms living in association with each other.
Endosymbiosis- a symbiotic relationship in which one organism lives inside the cells of another organism
Obligate relationship- a symbiotic relationship in which the organisms must live together and can not survive on their own.
Facultative relationship- a symbiotic relationship in which the organisms can live in association but do not have to.
 Mutualism- a symbiotic relationship in which each individual receives a benefit from the association.
Commensalism- a symbiotic relationship in which one organism receives a benefit and the other is neither harmed or receives a benefit.
Parasitism- a symbiotic relationship in which  one of the organism receives a benefit and the other is harmed
Some Examples of Symbiosis
Lichens are a complex symbiotic association that consists of a fungus (referred to as the mycobiont) with a photosynthetic partner (the photobiont). Generally the photobiont is a green alga or cyanobacterium. Occasionally, it appears that all three can also form a symbiosis. Lichens occur in some of the most extreme environments on Earth including places where not much can survive including arctic tundra, hot deserts, rocky coasts, and toxic environments. You may have seen them growing on tree branches or rocks in Minnesota. Despite their ability to tolerate harsh conditions, they are intolerant to air pollution, acid rain, and heavy metal contamination. The Lichen Song (http://www.youtube.com/watch?v=lWQaEI9fKZc&feature=related)
Anglerfish are deep sea predators. They generally have a long filament that extends in front of their mouth and is bioluminescent to attract prey. This bioluminescence is a result of symbiosis with bacteria. Anglerfish http://www.youtube.com/watch?v=9frgs8lUNac&feature=related
Ant Plants or Myrmecophyte is a plant that forms a symbiosis with ant colonies. The plants have structural adaptations that house the ants. The plant provides the ants with food and shelter in return for the nutrients from the ants.  The ant plant http://www.youtube.com/watch?v=F4JtQylW9ZY
Oxpeckers are birds found on the backs of mammals in Africa. These birds feed on ticks and other parasites found on their animal host. In addition, they feed on insects around the area where the host is foraging and sometimes on the wounds of the host. Oxpecker  http://www.youtube.com/watch?v=Qqa0OPbdvjw&feature=fvwrel

Bacterial Symbiosis

Microorganisms are estimated to make up most of the biomass found on Earth. It appears that have been evolving for almost 4 billion years. They are found every environment where we have looked for them. From deep sea ocean vents to inside arctic ice, even inside and on the human body. The diversity and range of microorganism’s adaptations indicate that they long ago “solved” many problems that we do not have solutions to. Throughout these modules, hopefully you have learned that microorganisms are an integrated part of all process that takes place on Earth.

The difficult part of working with bacteria is that they are tricky to get out of their environment and into isolation. It is estimated that less than 1% of the bacterial species are in culture. In order to manipulate a bacteria and maintain it in culture we must mimic it’s natural environment. For example, if we want to find bacteria that can use cellulose as a food source, we would make media that contained cellulose. Although it is difficult to identify, purify, and maintain pure cultures of bacteria, it is necessary in order to identify potential uses for compounds they make.  

Potential Microbial Applications-from DOE Micro project

Researchers have only scratched the surface of microbial biodiversity. Knowledge about the enormous range of microbial capacities has broad and far-reaching implications for environmental, energy, health, and industrial applications.

• Cleanup of toxic-waste sites worldwide.
• Production of novel therapeutic and preventive agents and pathways.
• Energy generation and development of renewable energy sources (e.g., methane and hydrogen).
• Production of chemical catalysts, reagents, and enzymes to improve efficiency of industrial processes.
• Management of environmental carbon dioxide, which is related to climate change.
• Detection of disease-causing organisms and monitoring of the safety of food and water supplies.
• Use of genetically altered bacteria as living sensors (biosensors) to detect harmful chemicals in soil, air, or water.
• Understanding of specialized systems used by microbial cells to live in natural environments with other cells.

Visit the link below and check out some research that is going on in the field of symbiosis. Many of their experimental designs are simple and can be adapted to other systems. When you are in Costa Rica, what questions about symbiosis, nutrient cycling, plant/insect/microbial interactions are you interested in answering?
What tools will you have to answer these questions?
Can you design a simple experiment to answer your questions?
http://web.uconn.edu/mcbstaff/graf/Sym.html