Wednesday, February 22, 2012

Carbon cycling in Antarctic psychrophilic yeasts: A new collaborative study


This winter, we started a new study investigating the unique metabolism of a couple of species of psychrophilic yeasts (Dioszegia cryoxerica and Cryptococcus vishniacii). Psychrophilic organisms are restricted to growth below 20oC, and these particular yeasts use unique metabolic carbon pathways. The yeasts used in this study may be of interest to the energy industry as potentials for the production of biofuels due to their unique metabolism.

This collaborative study consists of two parts: we handle the culturing and the “quenching” of the yeasts, and then the samples are sent to Dr. Joseph Dalluge at University of Minnesota so that he can study how growth at different temperatures affected their metabolism. Quenching refers to suddenly stopping the metabolism of the entire yeast culture by flushing it with large volumes of 60% methanol solution. Then the yeast cells are removed from both the quenching solution and the media in which they grew by centrifugation. The yeast cells, and samples of the quenching solution and the media were then sent to Joe for further analysis. We’re excited to find out how our little critters did!


Dr. Joseph Dalluge, Director of the Mass Spectrometry Facility at the University of Minnesota


Adding the quenching solution to the yeast culture


Keeping the quenched culture (left) and 60% methanol solution for future quenching (right) cool at -50oC


Now that the culture has been quenched, we need to centrifuge the cells out of the solution. We do this in a pre-chilled centrifuge to make sure our samples stay cold.