An Investigation On The Bacteriostasis And Mechanisms Of Hirsutella Sinensis Along Different Growth Stages

Ophiocordyceps sinensis is a rare medicinal fungus which is formed by asexual fungus Hirsutella sinensis and its host larva of Ophiocordyceps sinensis.A large number of modern clinical medical research results have found that Ophiocordyceps sinensis has various pharmacological activities such as reducing blood sugar,anti-oxidation,anti-tumor,anti-fibrosis,anti-inflammatory,and anti-bacterial.Nowadays,the research on Ophiocordyceps sinensis mainly focuses on anti-oxidation,anti-tumor and chemical components analysis,but there is little research on the mechanism of producing anti-bacterial substances.In this study,the anamorphic type of Hirsutella sinensis was used as the research object to explore the antibacterial metabolic mechanism of Ophiocordyceps sinensis.The main conclusions are as follows: First,The bacteriostatic experiment found that liquid-cultured Hirsutella sinensis and its secondary metabolites were not bacteriostatic,while solid-cultured Hirsutella sinensis began to show antibacterial phenomena when cultured at 18℃ for 14 days.Second,Transcriptome sequencing was carried out at different culture stages of H.sinensis,and the differentially expressed genes at different stages of antibacterial phenomena were analyzed.Through genome sequencing and NECAT software assembly annotations,the research group obtained the third-generation genome data of H.sinensis.The total genome is 6.86 G,the sequencing depth is 61.74 X,and finally 8,197 genes are obtained.The genome measured by the research group is used as the reference genome.The transcriptome data of each stage of H.sinensis obtained in this study were analyzed for differentially expressed genes in the parametric genome.Based on whether there is antibacterial phenomenon as the boundary,comparative transcriptome analysis results found that the Phenylpropanoid biosynthesis pathway（Phenylpropanoid biosynthesis）may be related to the production of bacteriostatic substances in H.sinensis,and cctP,bglA and KatG genes jointly regulate phenylpropanine Material biosynthesis.The metabolism of phenylpropanine substances is turned on by the phenylalanine ammonia lyase（PAL） synthesized by cctP.The high expression of bglA and KatG promotes the synthesis of antibacterial substances.At the same time,cctP is regulated by the biochemical reaction products mediated by bglA and KatG.The research results lay a foundation for understanding the law of bacteriostatic substances produced by H.sinensis under different culture conditions and related gene expression patterns,and provide important theoretical support for the application of the pharmacological activity of bacteriostasis of H.sinensis.