BS 375 Lecture Notes - Jim Wynorski, Extreme Environment, Extremophile

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wrygaard6

15 Jan 2023

School

University of the Sciences

Department

Biological Sciences

Course

BS 375

Professor

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Document Summary

Unit 2 part 4 - microbes as a component of extreme. Environmental conditions (e. g. ph, temperature, salinity, relative humidity, and nutrients) are at one of the extreme limits, i. e very low or very high. These conditions select for extremely low microbial diversity. Extremophiles: any organism that has successfully adapted to environments, where it is difficult or impossible for other organisms to survive. Extremophiles are able to grow in environments such as . Extreme environments include: high temperature (nearly boiling, low temperature (nearly freezing, low acidic values (ph values, high alkaline ph values, low water availability, high radiation, low nutrient concentration, high concentration of toxic compounds. The microbes which habitat under such conditions have special adapted features. Types of extreme environments: air-water interface, high temperature, high salt concentration, very low ph or very high ph value, high pressure. Air-water interface includes: high level of solar radiation, accumulation of toxic substances (heavy metals/pesticides, high temperature, high ph, high competition.

Related Questions

Extremophiles have been found flourishing in hot, acidic sulfur springs, around hydrothermal vents deep in the ocean, and in soil with high levels of toxic metals. What does the existence of life in such extreme environments say about the possibility of life on other planets?

I need help on this microbiology question:

Contrary to our favorite science fiction books and movies, the chances of us finding another planet with a civilization comparable to, or even more advanced than our own, seems highly unlikely. But, through your work as a microbiologist at NASA, you have been able to help change our views as to what forms of life we should be looking for on planets in our solar system and around neighboring stars. Instead of radio signals or errant transmissions, we have begun looking for planets that have environments similar to those capable of sustaining life as we know it here on Earth. To determine what we could find out there, you have begun studying different unique and atypical environments found here on Earth. Although the harsh conditions of hot springs or undersea sulfur vents seem incompatible with most forms of life, organisms known collectively as "extremophiles" have still managed to survive and adapt to these extreme conditions. You believe extremophiles may help you gain insight into the potential metabolic requirements, processes, and challenges of extraterrestrial life. Thus far in your search, you have identified some prokaryotic cells that have evolved to survive in the extreme conditions of sulfur vents on the sea floor. These vents are found at great depths, where the crushing pressure and lack of light and oxygen are prohibitive to many forms of life. Bacteria that are not considered extremophiles reside in most ecological niches on this planet. There are some common criteria for the environment that would sustain these bacteria. Availability of water, pH that lies between 5 and 9, temperatures that will remain steady and below boiling; these are some of the characteristics that bacteria will require in their environment if they are to succeed. But in the environment of the ocean floor vents, not only is the pH of the water very low, but also the water temperature is unusually high due to the geologic activity that fuels the vents. Organisms that are adapted to such harsh conditions have necessarily evolved enzymes able to function beyond average optima, as well as a chemosynthetic metabolism capable of using vent organic and inorganic compounds as energy sources.

Part A - Comparable Earth Environments to Be Found on Another Planet

You identify the prokaryotic cells you've found as a species of bacteria. These bacteria appear to be living off of nutrients and sulfur compounds released from the vents on the sea floor. Over time, the bacteria must have evolved extreme metabolic and enzymatic capabilities to allow them to tolerate and even benefit from the extreme depths, the lack of oxygen, the low pH of the surrounding waters, high temperatures due to volcanic releases, and the unique nutrient source of the vents.

Choose the characteristics and their impact on enzyme activity that are not correct from the following statements. (more than one may be chosen)

Archaea are able to tolerate highly acidic pH environments and have proteins that will not denature in the low-pH environments that the bacteria are found in.

Archaea are able to colonize water that is at or above the boiling temperature due to high levels of disulfide bridges that maintain the three-dimensional structure of the enzyme.

Archaea are only able to survive exceedingly well at high temperatures due to the amount of activation energy required by their enzymes.

Archaea are able to grow in extremely shady or low-light conditions that allow for optimal enzyme activity.