Fungal Solid-state Fermentation Teas And Its Teadenol-producing Potentiality

Black tea is one of the six major teas,with obvious functions such as lipidlowering blood pressure,anti-oxidation and other pharmacological and health care functions.The change of bioactive substances in black tea is the main reason why black tea has a variety of biological functions.Therefore,research on the formation and variation of the basic substances and quality of black tea is a research hotspot and a difficult point.The characteristic substances in black tea are studied.The combination of which microorganisms acts on the research and development of the functional materials of black tea is of great significance for improving the quality and commercialization of black tea.The aim of this thesis is to screen out strains of highly productive functional Teadenol compounds.Studies have shown that Teadenol is derived from the catechins in tea by metabolic products of Aspergillus genus.It has significant lipid-lowering,anti-oxidation and other functions to study high yields.Compounds provide potential value for industrialized microbial fermentation of tea,while at the same time selecting strains for artificial controllable fermentation of black tea,selecting fermentation parameters and methods for chemical analysis,and providing a method for studying the effects of alfalfa microorganisms on the chemical quality of dark tea from the level of small molecule compounds.Kinds of ideas.In this paper,the traditional separation and identification methods were used to isolate and identify the fungi from different sources.The optimum temperature of fungi and the temperature of solid fermentation of single strain were screened.The sensory evaluation and physicochemical analysis of the selected strains of fermented tea were screened out.For tea,the single-strain solid-state fermented tea that was selected was analyzed for the production of the target compound by HPLC-MS and other techniques to obtain a strain with a high yield of the target compound,and then the target compound Teadenol was isolated by high-throughput HPLC-MS,NMR and other methods.Identification and analysis finally led to the achievement of high-yield strains of Teadenol compounds.The research results of the paper are as follows:(1)Isolated from Puerh tea and Hunan black tea fungus and 13 exogenous fungi.After traditional methods of isolation and identification,a total of 34 strains of fungi were isolated from 6 different genera,belonging to Aspergillus(Aspergillus oryzae,Ranaria spp.,Aspergillus niger).),Penicillium,Rhizopus,Curvularia,Rhizoctonia,and Yeast.(2)Select the optimum temperature for separating the fungus from the tea broth and common medium at 30 °C and 37 °C.Through a single strain of solid state fermentation,37 °C was determined as the fermentation temperature,and the strains with poor treatment effect and strains were screened out.The sensory evaluation of the selected strains,the water extracts,and the crude polysaccharide values were measured.The strains with poor sensory results were screened and 20 strains of fungi were selected as fermentation strains.(3)HPLC-MS methods were used to compare the content of target compounds in solid-state fermented teas of different strains of fungi.Aspergillus strains D17B35,D17B50,D17 DA,D17DB,D17 HA,D17HB,D17A3,D17 DC,and D17A2 were used to detect target compounds A and B.Aspergillus genus D17A3 produced the highest amount of target compounds when fermented at a water content of 50% for 20 days.As a target strain,strain D17A3,which produces a higher yield of the target compound Teadenol compound,was finally selected.(4)The target compounds A and B produced by the high-yield strain D17A3 were analyzed by HPLC-MS,NMR and other methods,and the results showed that the retention time was 15.5 min at the mass-to-charge ratio of the [MH]-1 275.05 mass spectrum.The compound A was Teadenol A and the compound B produced was Teadenol B with a retention time of 18.7 min.