Temperature Stress

Abstract:  Acanthamoeba castellanii (A. castellanii) is a common soil‐ or water‐borne protozoon that feeds on bacteria by phagocytosis. A. castellanii can grow between 4 and 32°C and has to adapt quickly to chilling in order to survive. We have identified a Δ12‐fatty acid desaturase as key to low temperature adaptation. The activity of this enzyme is mainly increased through gene expression and new protein synthesis. Interestingly, the activity can also be altered independently by dissolved oxygen levels. In addition, we have identified a gene for the Δ12‐desaturase, which, when expressed in yeast, catalyses Δ15‐desaturation also. Moreover, it is also capable of producing very unusual n‐1 polyunsaturated products.

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