Studies On Hypoglycemic Activity Of Products From Bioconversion Of Kelp By Medicinal Fungus

With the deep domestic and international development and utilization of marine resources,marine microorganisms,marine plants and animals in the fields of food and medicine,have become increasingly important.Kelp is one of the most important biomass resources in China's coastal areas.It is rich in nutrients and bioactive components and has important nutritional and medicinal values.Although the production of kelp in China has been increasing,the use of kelp has been relatively modest.There are many reasons for the inadequacy of their deep utilization,such as the weaknesses of basic theoretical research,the complexity of applied research,etc.With the development of traditional medicine in our country,the biological activity of medicinal fungus,such as hypoglycemic,antihypertensive,anti-tumor,anti-oxidation,and immunomodulatory activities have received more attention.In order to explore new ways for the development of nutritional value and medicinal value of kelp,this study used medicinal fungus as tested strains to biotransform kelp and optimize product extraction conditions and solid fermentation formula,and study the hypoglycemic activity of products from bioconversion of kelp by medicinal fungus.In this article,the growth rate and hypoglycemic activity were used as indexes to select the best strains,and the extraction conditions were selected based on the extract yield and hypoglycemic activity.Then,the hypoglycemic activity was used as the screening index to optimize the design of the solid fermentation medium formulation.Optimal design for uniform design was obtained;then the hypoglycemic activity of bioconversion products was studied and high-efficiency products were screened out.Firstly,the medical fungus strains were screened with kelp solid medium.Three strains,M4,S44 and P3,were obtained based on the growth rate and the hypoglycemic activity of the product.Then,taking the hypoglycemic activity of the product as the main index and taking the product extraction rate as the consideration factor,the extraction conditions were selected to obtain the best extraction conditions for the medicinal fungi M4,S44 and P3 single transformed kelp products:the solid-liquid ratio was 1:38,extraction time was 186 min;it was preliminary determined that bioconversion products had higher hypoglycemic activity than the blank control,and the solid fermentation formula was further optimized.Secondly,through optimizing the uniform design of the solid fermentation formula with the hypoglycemic activity of the product as the index,the optimal formula for the fermentation formula of the M4,S44 and P3 strains was established.The optimized product activities of M4,S44 and P3 were 3.47,2.49 and 2.68 times higher than before.Thirdly,the hypoglycemic activity of single bioconversion products of M4,S44 and P3 strains of medicinal fungi and their optimized products were further studied.The IC₅₀ values of the hypoglycemic activity of single bioconversion products and optimized products of each strain were determined.It was found that the IC₅₀ value of the M4 fermentation product after optimization was:0.2043±0.0215 mg/mL,which was 494.71%lower than that of the untransformed kelp,and 247.38%lower than M4 single bioconversion product.The IC₅₀ value of P3 fermentation product was 0.2226±0.0421 mg/mL,which was 445.82%lower than that of untransformed kelp and 149.51%lower than P3 single b ioconversion product.The IC₅₀ value of the fermentation product of S44 was 0.2339±0.0539mg/mL,which was 419.45%lower than that of untransformed kelp and 167.59%lower than the S44 single conversion product.Then,the ultra-products were separated and purified by means of ultrafiltration,and the components with different molecular weights were tested for hypoglycemic activity.The molecular weight levels of the highly active components of the product were initially determined,which was used for the subsequent identification,characterization and hypoglycemic of the product.The study of the mechanism laid the foundation.Through the study of the solid fermentation formula of the bioconversion of kelp by medicinal fungus,and the product extraction conditions,as well as the determination of the hypoglycemic activity of bioconversion products,it was found that the products from bioconversion of kelp by medicinal fungus have a higher hypoglycemic activity,indicating that products from bioconversion of kelp by medicinal fungus have a high food and medicinal value.It is a new method for the development and utilization of high value resources for kelp,and it also provides ideas and certain scientific basis for the deep utilization and high-value resources of marine biomass.