Stoichiometry And Homeostasis Of Terrestrial Fungi Obtained Near Irvine, California

Transcript

The carbon, nitrogen, and phosphorus (C:N:P) ratios of 43 terrestrial fungal isolates acquired near Irvine, California, were analyzed and compared to the Redfield ratio (106:16:1) and global soil microbial biomass (60:7:1). To evaluate level of homeostasis or plasticity (non-homeostasis), three of the isolates (Davidiella, Mucor flavus, Helotiales) were grown in malt-yeast extract treatments with modified nutrient ratios. Carbon and nitrogen levels were measured using combustion analysis. Soluble organic phosphorus was extracted using heated HCL and analyzed with a molybdenum reagent indicator and spectrophotometer. The average C:N:P of the 42 fungal strains was 153:31:1. The three isolates grown in nutrient-modified media exhibited weak homeostasis with respect to C:N, weak plasticity with respect to N:P, and strong plasticity with respect to C:P. These results suggest that the local terrestrial fungi around Irvine are controlled by environmental conditions, and their growth is both nitrogen- and phosphorus-limited. Research paper for an REU internship under Dr. Adam Martiny at the University of California, Irvine.