Assessing how biotic and abiotic factors impact survival of Batrachochytrium dendrobatidis zoospores
Location
SU-217
Department
Biology
Abstract
Batrachochytrium dendrobatidis, the amphibian chytrid fungus known as Bd, is one of the greatest threats facing amphibians. Bd has been the leading cause of frog deaths in the rainforests of Australia and Panama since it was first described in 1993. The disease associated with Bd, chytridiomycosis, is fatal in post-metamorphic frogs. In this study, we aim to understand how abiotic and biotic environmental factors impact Bd zoospore survival, and how climate change may be a driving force behind increased chytrid spread. Abiotic factors related to global warming such as rising temperatures and CO2 were examined first. Zoospores were incubated in the experimental environment and live zoospore counts were assessed at days 4, 8, and 12. Zoospores thrived from 17-35 degrees Celsius, with modest inhibition at 35 degrees, suggesting that as climate change warms environments, the Bd zoospores will persist in the environment. We found that a CO2 rich environment does not inhibit the free-swimming zoospores but enhances survival. We also tested four soil Bacillus species that have some antifungal properties to determine their impact on Bd zoospores. Each Bacillus species was cultured in BHI broth and Bd zoospores were directly exposed to the conditioned supernatant to yield qualitative and quantitative impacts on zoospore survival. Bacillus thuringiensis was the most consistent inhibitor suggesting that it may provide a protective effect to amphibians. Together, these findings suggest that climate change, its causes and effects, are increasing zoospore survival, but may also enhance inhibitors in some environments. Future work consists of exposing zoospores to common fertilizer components as well as combining abiotic factors.
Faculty Sponsor
Emily Rumschlag-Booms
Assessing how biotic and abiotic factors impact survival of Batrachochytrium dendrobatidis zoospores
SU-217
Batrachochytrium dendrobatidis, the amphibian chytrid fungus known as Bd, is one of the greatest threats facing amphibians. Bd has been the leading cause of frog deaths in the rainforests of Australia and Panama since it was first described in 1993. The disease associated with Bd, chytridiomycosis, is fatal in post-metamorphic frogs. In this study, we aim to understand how abiotic and biotic environmental factors impact Bd zoospore survival, and how climate change may be a driving force behind increased chytrid spread. Abiotic factors related to global warming such as rising temperatures and CO2 were examined first. Zoospores were incubated in the experimental environment and live zoospore counts were assessed at days 4, 8, and 12. Zoospores thrived from 17-35 degrees Celsius, with modest inhibition at 35 degrees, suggesting that as climate change warms environments, the Bd zoospores will persist in the environment. We found that a CO2 rich environment does not inhibit the free-swimming zoospores but enhances survival. We also tested four soil Bacillus species that have some antifungal properties to determine their impact on Bd zoospores. Each Bacillus species was cultured in BHI broth and Bd zoospores were directly exposed to the conditioned supernatant to yield qualitative and quantitative impacts on zoospore survival. Bacillus thuringiensis was the most consistent inhibitor suggesting that it may provide a protective effect to amphibians. Together, these findings suggest that climate change, its causes and effects, are increasing zoospore survival, but may also enhance inhibitors in some environments. Future work consists of exposing zoospores to common fertilizer components as well as combining abiotic factors.