Screening,Breeding And Application Research Of Qiongglulyase Strain

Seaweeds,including laver,kelp,wakame,etc.,are algae that grow in the ocean and produce energy through photosynthesis.Seaweed is rich in polysaccharides,and as a natural biopolysaccharide,agar is affected by its high viscosity,good gel performance,and difficult to decompose,resulting in its application in medical and health,food additives,pharmaceutical industries,etc.restricted.Agar lyase can hydrolyze agar polysaccharides,and its degradation product agar oligosaccharides has many biological activities,such as anti-aging,anti-disease and antibacterial,enhancing immunity,anti-starch aging,etc.It is used in new drugs and new functional foods.The research and development field of high-end cosmetics has shown good application prospects.By screening high-yielding agar lyase strains and optimizing their fermentation conditions,the research on the enzymatic hydrolysis of Asparagus spp.and the application of its product agar oligosaccharides have important practical significance.In this paper,the intestinal tissues of abalone were ground and screened by the screening medium,and the strain was inoculated on the solid medium by the streaking method.After cultivation,the agar lyase strain M1-M22 was obtained.A single strain M19 was selected and amplified by 16S r DNA-PCR to obtain the 16S r DNA sequence of the strain.After verification by agarose gel electrophoresis,the amplified samples were taken and sent to the gene sequencing company for sequence determination.Use Gen Bank to perform BLAST comparison of the sequencing results and perform nucleotide sequence analysis to confirm that the species of bacteria M19 is Vibro sp.CF4-11.The response surface design method was used to optimize the medium composition of agar lyase-producing strains,and a quadratic regression model of Ca Cl₂ concentration,agar concentration,and peptone concentration on the agar lyase activity was established.The best medium group was Na Cl 40 g/L,Ca Cl₂ 1.1 g/L,agar 4.4 g/L,protein 2.3 g/L,Mg SO4 6 g/L,yeast extract 8 g/L.Under this condition,the enzyme activity is 55.60 U/ml,which is 89%higher than before.The strain can be cultivated as a new strain with potential application value,can efficiently produce agar lyase,provide new microbial resources for the industrial production of agar oligosaccharides,and play an important role in promoting the deep processing and utilization of marine resources.The agar oligosaccharides were prepared by the agar lyase enzymatic hydrolysis method with Asparagus as raw material.The enzymatic hydrolysis time was 4h,the substrate concentration was 0.5%,the p H value was 6.5-7.5,and the enzymatic hydrolysis temperature was determined by a single factor test.40-50℃,the amount of enzyme added is 25-35U/m L,and on the basis of single factor experiment,orthogonal test is used to optimize the preparation process to determine the best agar lyase to prepare agar oligosaccharide by enzymatic hydrolysis of Asparagus The process conditions are:temperature 45℃,p H value 7.0,adding enzyme amount 35U/m L,time4h,substrate concentration 0.5%,under these conditions,the hydrolysis degree of Asparagus is 33.3%.The mass-to-charge ratio of the product obtained from the enzymatic hydrolysis was measured,and the molecular weight distribution of the enzymatic hydrolysis product was determined to be 500-1000,the degree of polymerization was 3-5,and trisaccharides were the main ones.The single-factor experiment proved that the asparagus oligosaccharides have a significant promoting effect on the growth of Discus hannai,and the growth effect of the compound feed with different proportions of aspartame oligosaccharides and the full compound feed was compared,The growth rate of Haliotis discus wrinkled with Asparagus oligosaccharides increases,the survival rate rises,and the quality is improved mainly in the increase of protein and fat content.In addition,different soaking solutions were used to study the effect of agar oligosaccharides on the water retention and freshness of abalone and scallops during freezing.Three indicators were studied,namely,thawing loss rate,cooking loss rate,and texture.Compared with the sodium alginate immersion group,Asparagus oligosaccharide soaking group has obvious advantages in water preservation and freshness preservation.