Study On Extraction And Purification Of Protamine From Takifugu Obscurus And Its Preservation Effects

Protamine is mainly a basic protein extracted from the mature testis tissue of fish.It is rich in arginine and has the advantages of high safety,good corrosion resistance and high thermal stability.It is used in food antibacterial,testing,medicine and pharmacy.The field has a wide range of applications.In addition,protamine also has high nutritional and functional properties,lowering blood pressure,inhibiting tumors,antithrombotic,strengthening liver function and inhibiting blood coagulation.However,in the food field,protamine is mainly used as a preservative.In this paper,Takifugu obscurus testis was used as raw material to extract protamine,and the optimal extraction process and antibacterial activity of the spermatozoon of Takifugu obscurus were explored,and the dark-streaked oriental eel protamine complex was studied.Preservative effect of preservatives on P.vannamei.In this paper,the testis of Takifugu obscurus was used as the raw material,and the protamine was extracted by acid extraction.The extraction coefficient was used to determine the optimal extraction parameters.According to the results of orthogonal test,the importance factors of the extraction of protamine are as follows: extraction times >sulfuric acid dosage > sulfuric acid concentration > 95% ethanol;optimal extraction conditions are: sulfuric acid concentration 0.2mol/L,sulfuric acid dosage is 2.5 times,the number of extractions was 2,and the amount of 95% ethanol was 2.5 times.Under this condition,the extraction rate of protamine from Takifugu obscurus was 3.82%,and the protein content was 89.01%.According to the tricine-SDS-PAGE,the extracted crude protamine has two bands with molecular weights of 25 and 20 KDa,respectively.Analysis of its lytic acid composition found that arginine and alanine content were relatively higher,accounting for 31.40 and 17.39%,respectively.This study is of great significance for the efficient use of testes of puffer-fish(Dark-spotted oriental carp),and also lays a theoretical foundation for the application of stag beetle(Dark-spotted oriental carp)protamine in the food and pharmaceutical fields.To purify the crude extract of Takifugu obscurus protamine,and explore itsantibacterial properties.In this study,Sephadex G-50 and CM Sepharose Fast Flow were used to purify the spermatozoa of Takifugu obscurus.Identification of protamine by arginine color reaction.The effects of protamine on the minimum inhibitory concentration,inhibition zone diameter and growth curve of Staphylococcus aureus,Escherichia coli and Salmonella were determined.The results showed that the spermatozoa of Takifugu obscurus had an absorption peak at 217 and 273 nm,respectively,and the absorption peak at 217 nm was higher.The purified protamine was found to be better than the protamine before purification by SDS-PAGE electrophoresis.The strips are fine and have no tailing.The Takifugu obscurus protamine has inhibitory effects on Gram-negative bacteria(Salmonella and Escherichia coli)and Gram-positive bacteria(Staphylococcus aureus),which can delay the bacteria The growth of the species,the minimum inhibitory concentrations against Staphylococcus aureus,Escherichia coli and Salmonella were 500,1000 and 1000 ppm,respectively.Among them,the antibacterial effect against Gram-positive bacteria(Staphylococcus aureus)is more significant.In this work,food preservatives containing protamine and chitosan was developed to extend the shelf-life of P.vannamei.The preservation parameters including p H,thiobarbituric acid(TBA),water holding capacity,total bacteria count(TBC),k-value,totac volatile baice nitrogen(TVB-N),chromatic aberration and sensory evaluation was employed to investigate the effect of 1% acetic acid(CK),0.01 g/m Lchitosan(CTS),0.005 g/m L protamine(PTM),0.01 g/m L chitosan + 0.001 g/m L protamine(CP1),0.01g/m L chitosan + 0.003 g/m L protamine(CP2),0.01 g/m L chitosan + 0.005 g/m L protamine(CP3)preservatives on the preservation of P.vannamei at 4?.Compared to CK treatment group,can more effectively inhibit the increase of p H,thiobarbituric acid(TBA),total bacteria count(TBC),K-value,totac volatile baice nitrogen(TVB-N)and water holding capacity decline.The results showed CP2 treatment groups all exhibited good antibacterial and anti-oxidative activities than CP1 and CP3 ones,thus prolonging the shelf life of P.vannamei.The CP2 treatment group had the best effect.