Isolation And Identification Of Moulds From Raw-Furs Of Raccoon Dog/Fox/Rex Rabbit And Screening Of Anti-Mould Pharmaceutical Preparation

Fur animal farming is an important part of the livestock farming industry,mainly providing the raw material of hides and skins needed for the production of high-grade clothing.With the development of society,people’s requirements for fur products are becoming higher and higher,among which the quality of raw hides directly affects the quality of finished fur products.The aim of this study is to isolate and identify the predominant moulds that cause mildew in raccoon and fox hides,and to analyse their biological characteristics,so as to screen for highly effective mould inhibiting agents that can inhibit their growth and provide a theoretical and methodological basis for extending the storage time of hides and protecting their economic value.Firstly,the moulds were isolated and purified from the raw hides of raccoon,fox,rex rabbit,and their DNA was extracted and molecularly identified using 18s r DNA primers,and the sequencing results were compared with Blast in the NCBI database to find sequences with high homology and construct a phylogenetic tree to identify the dominant moulds causing the moulds.Secondly,to understand the growth characteristics of the dominant moulds,the growth of the dominant strain was observed by adjusting the culture conditions and studying the mycelial growth of the dominant moulds after 72 h of incubation under different temperature,light and p H,etc.The optimum growth conditions of the dominant moulds were selected and the biological characteristics of the dominant moulds were analysed.Thirdly,the mycelial growth rate method was used to determine the inhibition of mycelial growth of the dominant moulds by six anti-mycorrhizal agents,and the mycelial growth of the dominant moulds in the medium containing different concentrations of anti-mycorrhizal agents was observed.anti-mould agents.Fourthly,the screened anti-mould preparations were sprayed onto the raw hides of the otters inoculated with the dominant moulds and the hides were observed daily to analyse the effect of the anti-mould preparations on the inhibition of the hides and to select the most effective and suitable anti-mould preparations for production.Finally,the screened anti-mould preparations were prepared and sprayed on the raw hides of the rabbits,while the control group was sprayed with an equal amount of pure water and stored at room temperature.The hides were checked monthly for preservation and analysed by mould isolation,PCR identification and visual observation to determine the effectiveness of the anti-mould preparations in preventing and prolonging the preservation of the raw hides of the rabbits.The results show that the dominant moulds causing mould in rex rabbit hides are Trichoderma,Aspergillus and Mucor.The most suitable conditions for the growth of the dominant moulds were found to be 25°C and p H 7.Trichoderma spp.grew fastest under 12h/12 h alternating light and dark conditions,while Aspergillus flavus and A.longicornis grew best under 72 h total darkness.According to the EC₅₀ value,the mould inhibiting effect of the six mould inhibiting agents in descending order were OIT,mycotoxin,IPBC,salicylic acid,sodium diacetate and potassium sorbate.Mycotoxin,IPBC and OIT were selected for the rawhide mould inhibition test,which showed that when the concentration was EC₅₀/mg·L^-1,mycotoxin could be preserved for 14 days for rawhide sprayed with Trichoderma,15 days for sprayed with Aspergillus and 17 days for sprayed with A.longum;IPBC could be preserved for 8 days for rawhide sprayed with the three dominant moulds;OIT could be preserved for 8days for rawhide sprayed with Trichoderma or OIT can be preserved for 10 days when sprayed with Trichoderma or Xylella,and for 8 days when sprayed with Aspergillus.At a concentration of EC₉₅/mg·L^-1,mycotoxin can be preserved for 20 days on raw hides sprayed with Trichoderma,18 days with Aspergillus and 22 days with A.longum;IPBC can be preserved for 13 days on raw hides sprayed with Trichoderma or A.longum and 11 days with Aspergillus;OIT can be preserved for 15 days on raw hides sprayed with Trichoderma and 22days with A.longum.The raw hides can be preserved for 16 days when sprayed with Aspergillus flavus or A.longum.This led to the selection of IPBC and OIT for the application of raw rabbit hides.The results showed that mould could be isolated in the control group at day 90 of storage and mould spots were observed with the naked eye at day 120;mould was isolated in the IPBC and OIT groups at 120 days of storage and mould spots were seen with the naked eye at day 150.The above results show that Trichoderma,Aspergillus and A.longum are the predominant moulds that cause mould in the raw hides of Rex Rabbits,and it was determined that the anti-mould preparations IPBC and OIT are effective in preventing and controlling mould in the raw hides of rex rabbits,providing a scientific basis for controlling mould in the production of raw hides and extending the shelf life of raw hides.