Species Diversity Of Keratin-degrading Fungi In The Special Eco-environment

Keratin widely distributed in animal ectoderm cells,due to its structural cystine disulfide bond highly cross-linked and intermolecular hydrophobic interaction and hydrogen bonding,it has the strong resistant.It is the third most abundant polymer in nature after cellulose and chitin.Keratin-degrading fungi and their keratinases had attracted the attention of researchers all over the world,because the fungal keratinases are easy to be purified and more easy to be available than bacterial keratinases.It is reported that the distribution of keratin-degrading fungi is greatly influenced by the activities of humans and animals,and the incidence of such fungi is high in areas where humans and animals are frequently active.Therefore,we selected some specific habitats such as animal surfaces,hospitals and parks to conduct research on such resources in order to expand our understanding of these fungal biodiversity and provide a scientific basis for public health and resource utilization.The main findings are as follows:1.Diversity of keratin-degrading fungi from body surfaces of different pet dogsUsing selective media with chicken feather as sole carbon and nitrogen sources,1 100 isolates of keratin-degrading fungi were isolated from dog hair at the back of ears,abdomen,cheek,dorsum,toenail and inside of hind legs of different pet dogs living in different three habitats.Fifty-two species in 26 genera were identified by morphology,barcode of Life Data Systems and phylogenetic analysis.According to the literatures and the International Society for Human and Animal Mycology rDNA-ITS Database,Alternaria alternata,Arthrinium phaeospermum,Aspergillus flavus,Chaetomium globosum,Cladosporium sphaerospermum,Cladosporium cladosporioides,Cladosporium tenuissimum,Curvularia pseudorobusta,Epicoccum cf.nigrum and Schizophyllum commune were of potential pathogenicity to human.The results showed that the diversity of keratin-degrading fungi and potential pathogenic fungi including some non-dermatophytes are varied and rich on the surface of pet dog.Pet dog lovers and people who close contact with dog should pay attention to contagious diseases caused by these fungi.2.Diversity of keratin-degrading fungi in soil samples from several hospitals in Sichuan,Guizhou province and Chongqing city774 isolates of keratin-degrading fungi were isolated from soil samples in several hospitals by the hair-baiting technique.Fifty-eight species in thirty-one genera were identified by morphology,barcode of Life Data Systems,UNITE Database,CBS Database and phylogenetic analysis.According to the literatures and the International Society for Human and Animal Mycology rDNA-ITS Database,the results showed that 512 isolates of 20 species in 13 genera,that is,Alternaria,Aspergillus,Chaetomium,Cladosporium,Fusarium,Geomyces,Geotrichum,Microsporum,Penicillium,Purpureocillium,Talaromyces,Trichoderma and Trichophyton were of potential pathogenicity to human.3.Diversity of keratin-degrading fungi in soil samples from Qianling Park in Guizhou province1 269 isolates of keratin-degrading fungi were isolated from 20 soil samples in Qianling Park by the hair-baiting technique.One hundred and six species in fifty-eight genera were identified by barcode of Life Data Systems,UNITE Database and phylogenetic analysis.Microsporum,Myceliophthora,Aphannoascus,Penicillium,Lophiostoma,Mortierella,Trichosporon and Fusarium,etc,are the dominant genera in the total isolates,whose percentage are 14.18%,13.24%,9.38%,7.11%,6.15%,6.15%,5.04%,4.10% of the total isolates,respectively.The results showed that there are abundant keratin-degrading fungi in the soil of Qianling Mountain Park in Guiyang,Guizhou Province.4.Description and identification of some keratin-degrading fungal taxonomic unitsSome isolates of keratin-degrading fungi were isolated from soil samples by the hair-baiting technique.Based on the morphology and the phylogeny analysis of ITS,?-tubulin and EF1 A sequences,six new species and one new record were identified and described,and belonged to Microsporum,Corynascus,Ctenomyces and Geomyces,respectively.