Our field of research primarily includes Microbial Ecology, understanding microbial community structure and metabolic diversity in ecosystems based on the nutrients and environmental conditions that primarily drive the ecosystem functions. Antarctic lakes are a perfect resource for studying microorganisms, since the food web in the lake ecosystems consists of microorganisms that have acclimatized to extreme conditions. The lakes of interest in our study are lakes Bonney and Fryxell in the McMurdo Dry Valley, Antarctica.
Photosynthesis forms the base of the food web in these lakes, hence in our study we utilize Chlamydomonas sp. ICE-MDV (pure culture), a green algal isolate from Lake Bonney, and enrichment cultures from lakes Bonney and Fryxell. The enrichment cultures are sourced from the natural communities present in the lakes. The objective of the project is to interpret the response of microorganisms isolated from Antarctica to stress conditions and compare growth and effects of stress conditions of the pure culture to enrichment cultures. The pure and enrichment cultures were grown and subjected to stress conditions namely: control (no stress), high temperature, high salinity, nutrient deficient, extreme shade, and oxidative stress. The growth and photosynthetic activity of these were then measured using Cell Countess, Spectrophotometer (Optical Density) and PhytoPAM (Fv/Fm) instruments, respectively. Our research indicates that natural communities more readily adapted to stress conditions as compared to pure cultures. Effects of stressors on pure culture can be attributed to changes on similar organisms in the natural community. Further research is necessary to confirm the results we derive in this experiment. Going forward this type of experiment could be performed on other isolated organisms from these environments to model stressor impacts on those organisms.
Authors: Rochelle Pereira, Trevor Powell
Faculty Advisors: Rachael Morgan-Kiss, Microbiology
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