Temperature tolerance of filamentous cyanobacteria from Indiana Dunes State Park

Abstract

Biological soil crusts (BSCs) are associations between microorganisms and the surface of the soil that occur in relatively undisturbed soils exposed to sunlight. They have been shown to stabilize soils and contribute to nutrient cycling in otherwise barren soils. Cyanobacteria are important microorganisms in BSCs because they initiate their development, serve as primary producers, and provide stability for the BSC microbial ecosystem. BSCs are known for their presence in open areas such as deserts, although they can be found in the more temperate environment of the Indiana Dunes State Park in the sand dunes along the Lake Michigan Lakeshore. With increasing temperatures, it is unknown as to how BSC microbial communities will respond and how a changing climate will specifically impact the cyanobacteria within these soils. Therefore, the objective of this research is to isolate cyanobacteria from BSCs of the Indiana Dunes and observe their temperature tolerance in comparison to cyanobacteria from arid deserts of the western US. It is hypothesized that strains from the Indiana Dunes will be more psychrotolerant and respond more similarly to Microcoleus vaginatus from the Colorado Plateau, than Microcoleus steenstrupii from the Sonoran Desert. Two strains of cyanobacteria were isolated from the Indiana Dunes and, following PCR and sequencing, were determined to most likely be strains of Leptolyngbya and Pseudophormidium. These two isolates, M. vaginatus, and M. steenstrupii were allowed to grow for 20 days at 10, 25 and 35oC. Their growth and survival will be determined by changes in the amount of chlorophyll and statistically compared to identify any significant difference in temperature tolerance between these strains. If Leptolyngbya and Pseudophormidium are unable to grow in warmer temperatures then their ability to colonize BSCs may be affected and this will have unknown consequences to the microbial ecosystems they harbor as temperatures increase.http://opus.ipfw.edu/stu_symp2017/1036/thumbnail.jp