title: Growth, keratinolytic proteinase activity and thermotolerance of dermatophytes associated with alopecia in Uyo, Nigeria.
abstract: Mycological research was conducted on the mycelial growth, keratinolytic proteinase activity and thermotolerance ofdermatophytes associated with alopecia patients in Uyo, Nigeria. The results revealed that Microsporum sp. - AP1, Epidermophyton sp. - AP2, Trichophyton rubrum - AP4, Trichophyton mentagrophytes - AP5 and a yeast Candida albicans - AP3 isolated exhibited variable growth and keratinase activity at different temperatures. Microsporum sp. - AP1 and T. mentagrophytes - AP5 survived heat treatment at 90 degrees C but exhibited best mycelial growth at 30 degrees C (with 53.41 mg/50 ml biomass dry weight) and 40 degrees C (with 61.32 mg/50 ml biomass dry weight) respectively, after incubation for 2 weeks. Trichophyton rubrum - AP4 and Epidermophyton sp. - AP2 could not survive heat treatment at 90 degrees C but grew better at 40 degrees C (with 38.52 mg/50 ml biomass dry weight) and 30 degrees C (with 48.32 mg/50 ml biomass dry weight) respectively, over the same incubation period, while C. albicans - AP3 grew better at 30 degrees C with 38.7 mg/50 ml biomass dry weight after 2 weeks, but failed to survive at 70 degrees C. All the isolates except Candida albicans - AP3 survived at 80 degrees C and exhibited great potential to elaborate keratinolytic enzymes, with T. mentagrophytes demonstrating the best potential at 30 degrees C and 40 degrees C. Higher temperatures tended to reduce keratinolytic activities and there were significant (P < 0.05) relationships between biomass weight and enzyme productivities of all the isolates except T. mentagrophytes. This indicates that in some dermatophytes keratinolytic proteinase activity is not a function of cell multiplicity. This plus the high thermostability of the enzymes are important attributes in the consideration of preventive and therapeutic methods against dermatophytes in the tropics.
authors.affiliation: Department of Microbiology, University of Uyo, P.M.B. 1017, Uyo, Nigeria. jomato652003@yahoo.com
authors.forename: J P
authors.initials: JP
authors.lastname: Essien
authors.forename: A A
authors.initials: AA
authors.lastname: Umoh
authors.forename: E J
authors.initials: EJ
authors.lastname: Akpan
authors.forename: S I
authors.initials: SI
authors.lastname: Eduok
authors.forename: A
authors.initials: A
authors.lastname: Umoiyoho
mesh_terms: D000505:Alopecia / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology*; D003883:Arthrodermataceae / Q000201:enzymology / Q000254:growth & development / Q000472:pathogenicity*; D003881:Dermatomycoses / Q000150:complications / Q000453:epidemiology / Q000382:microbiology*; D004795:Enzyme Stability; D018859:Hair Follicle / Q000382:microbiology; D006358:Hot Temperature; D006801:Humans; D003904:Mitosporic Fungi / Q000201:enzymology / Q000254:growth & development / Q000472:pathogenicity*; D009549:Nigeria / Q000453:epidemiology; D010447:Peptide Hydrolases / Q000378:metabolism*
chemical_list: D010447:Peptide Hydrolases; C035855:keratinase