Endogenous Respiration and Fatty Acids of Phialophora Dermatitidis

SUMMARY

Phialophora dermatitidis cells were grown at 37 C on Sabouraud-glucose agar for 1–35 da. At designated time intervals cell populations were characterized for endogenous respiration and fatty acid content. Young cells (1-da-old) were found to have a low level of endogenous respiration when starved in phosphate buffer. Older cell populations had increasingly higher levels of endogenous respiration. Using gas chromatography, fatty acid analysis of cells grown at 37 C for 1,5,14, and 35 da revealed little qualitative differences in major component fatty acids. The four most prominent fatty acids found were oleic acid (69–73%), palmitic acid (20–25%), palmitoleic acid (0.9-2.0%), and stearic acid (1.8-6.0%). Short chain fatty acids (C₁₂, C₁₄, C₁₅) were detected. Acids greater than C18 appeared in increasing quantities in cells incubated at 37 C for 5 da or more. Quantitative measurements of major component fatty acids of 1-da-old cells were approximately 5.1% in comparison to 5-da-old cells (6.9%), 14-da-old cells (33.2%), and 35-da-old cells (31.1%). It is believed that these large quantities of fatty acids constitute the prominent lipid bodies observed in older cells and account for the higher levels of endogenous respiration of P. dermatitidis.