Proteome sequencing and analysis of Ophiocordyceps sinensis at different culture periods.

BACKGROUND: Ophiocordyceps sinensis is an important traditional Chinese medicine for its comprehensive active ingredients, such as cordycepin, cordycepic acid, and Cordyceps polysaccharide. O. sinensis zjut, a special strain isolated from O. sinensis, has similar pharmacological functions to wild O. sinensis. Currently, O. sinensis with artificial cultivation has been widely studied, but systematic fundamental research at protein levels has not been determined. RESULTS: Proteomes of O. sinensis zjut at different culture periods (growth period, 3rd day; pre-stable period, 6th day; and stable period, 9th day) were relatively quantified by relative isotope markers and absolute quantitative technology. In total, 4005 proteins were obtained and further annotated with Gene Ontology, Kyoto Encyclopedia of Genes and Genomes database. Based on the result of the annotations, metabolic pathways of active ingredients, amino acids and fatty acid were constructed, and the related enzymes were exhibited. Subsequently, comparative proteomics of O. sinensis zjut identified the differentially expressed proteins (DEPs) by growth in different culture periods, to find the important proteins involved in metabolic pathways of active ingredients. 605 DEPs between 6d-VS-3d, 1188 DEPs between 9d-VS-3d, and 428 DEPs between 9d-VS-6d were obtained, respectively. CONCLUSION: This work provided scientific basis to study protein profile and comparison of protein expression levels of O. sinensis zjut, and it will be helpful for metabolic engineering works to active ingredients for exploration, application and improvement of this fungus.

Enhancement of protoplast preparation and regeneration of Hirsutella sinensis based on process optimization.

OBJECTIVE: To explore the optimal methods for the protoplast preparation and regeneration of Hirsutella sinensis by optimizing the limiting factors. RESULTS: During the treatment of enzymatic protoplast preparation, mycelium cultured for 7 days was the optimal start material. The maximum protoplast preparation rate of 4.3 × 107 protoplasts/g fresh weight (FW) was obtained after 0.5 h treatment of 1 mg/ml mixed lytic enzymes in KH2PO4-K2HPO4 buffer (pH 5.5) with 0.6 M KCl at 18 °C. As for the protoplast regeneration, the maximum protoplast regeneration rate reached 12.32% through 5 × 103 protoplasts mL-1 cultivated for 20 days in the regeneration medium with 0.6 M mannitol and 1.5% agar. CONCLUSIONS: The preparation and regeneration of H. sinensis protoplasts was firstly established based on process optimization and it provided a foundation for the study of H. sinensis mutagenesis.