ABSTRACT
Background and Purpose: Keratinolytic fungi [KF] are among the fungi existing in the soil, whose enzymatic activity causes the decomposition of keratinized material in the soil; they are also considered as one of the pathogenic factors. The present study was conducted to determine the enzymatic activity of the KF, and to evaluate the effect of climatic conditions on their activity
Methods and Materials: This descriptive cross-sectional study was conducted on 90 isolates of KF randomly selected from different regions in Iran and other countries in 2004. The samples were cultured in Modified Czaspex-dextrose liquid medium [MCDLM]. Their enzymatic activity was measured using Azocazein, the general subtilisin of serin proteinase, and chromogenic substrates including N-Suc-Ala-Ala-Pro-Phe-NA, N-Suc-Ala-Ala-Pro-Leu-NA and N-Bz- Phe-Val-Arg- NA. The obtained data were summarized using two-dimensional tables, and were analyzed using non-repeating one-way ANOVA and Tukey test in SPSS
Results: The results indicated that Myriodontium keratinophilum [94.6 micro/ml] and Microsporum coockei [81.66 micro/ml] had the highest Azocaseinolytic activity, and hydrolysed N-Suc-Ala-Ala- Pro-Phe-NA, N-Bz- Phe-Val-Arg- NA and N-Suc-Ala-Ala-Pro-Leu-_NA respectively. Statistically significant differences were onserved to exist between methods of determining enzymatic activity [P<0.05]
Conclusion: The results indicated that the enzymes secreted in these fungi were of a proteinase nature and belong to the subtilisin-like serin proteinase