Stress-driven metabolites of desert soil fungi

Microorganisms produce secondary metabolites to survive under stressful conditions. The effect of drought and heat stress on fungi isolated from Arabian desert soil during the hot (ca 40 degrees C) and cool (ca 10 degrees C) seasons was studied using the genome mining approach. The presence of three stress-related genes (calmodulin, polyketide synthase and beta tubulin) was analyzed molecularly using specific primers. The presence of the genes in desert fungi was compared to their antimicrobial (ten bacterial or fungal pathogens) and anticancer (liver, cervical and breast) properties and the production of thermostable enzymes (phytase and xylanase). The genes appeared to be present in the fungal sequence obtained during the summer, while none of the genes were present during winter. Appreciable differences were observed in enzyme activities, with summer activities high and winter low. The antagonistic activities of A. niger were relatively stable and varying, while those of P. chrysogenum were consistently higher in summer than in winter. The presence of the three genes seemed to correlate with the highly antagonistic activities of P. chrysogenum, while A. niger had relatively active winter isolates without any of the genes. The hot season in deserts yields fungal isolates with biological activities useful in biotechnological solutions.

Automated summary

Microorganisms in desert soil produce secondary metabolites to survive under drought and heat stress. The presence of stress-related genes in desert fungi was analyzed and compared to their antimicrobial, anticancer, and enzyme production properties. Differences in enzyme activities and antagonistic activities were observed between summer and winter isolates. The presence of certain genes seemed to correlate with highly antagonistic activities. Fungal isolates from the hot season in deserts have potential biotechnological applications.