Abstract
The fact that toxic species do not always produce toxins and that other species not known to produce toxins were found to be toxic in some environments have been previously reported. However, different fungal species behave unexpectedly in different ecosystems. That is why the main objective of this work was to detect the toxicity of some fungal species existing in some environmentally important ecosystem in Jeddah in order to find a correlation between some of these environmental factors and the detected toxicity. The aim is to use some of the isolated non toxic strains that are capable of acting upon some environmental pollutant as a bioremediation approach. Forty nine fungal isolates were isolated from six different sources and ecosystems in both terrestrial and marine environment (agricultural soil, wheat grain, sewage dump, oily sewage dump, soil around car oil dump and marine fauna). Aflatoxins were detected in 18.4% of the total isolates. All the isolates from marine environment were non toxic to brine shrimp.