Mutation Breeding Of High Extracellular Polysaccharides Strain By Ultraviolet And Study Of Culture Conditions

Polysaccharides exist in animal membranes, plants and micro-organism cliffsextensively,and are one of the four basic materials constructing life.The special marineenvironment leads to the distinction of the synthesis process between the ocean and landorganisms. People pay close attention to various bioactive substances with novel functionsand stuctures.In this paper,marine microorganism producing extracellular polysaccharides wasscreened from marine soil and lured complexly.The individual shape,fermentation conditionswere researched,and the polysaccharide extraction was also studied．Marine bacteria S-12was lured by UV and LiCl after purely,the mutagesis bacteria wasisolated and pured.The highly producing polysaccharides bacteria was isolated and namedmarine B106.The cultivated characteristic and cell shape were analysised.Through determining extracellular polysaccharides content by phenol-sulfuric acidmethod，better fermentate cultivation and culture condition of marine lured microorganismstrain B106which produce extracellular polysaccharides respectively were:cane sugar6%,yeast0.4%,maize starch0.8%,sea water40%； temperature26℃、 liquid-installed30mL/100mL、inoculate quantity8%, cultivation initial pH8，fermentation time120h. Underthese conditions，the yield of extracellular polysaccharides was497.41mg/100mL,17%morethan the starting bacteria. Raw polysaccharides yield were45%.The highest producingpolysaccharides were graded by75%alcohol.The main component of polysaccharides werefructose,2-methyl rock algae candy,3,4-2methyl glucose and4-methyl rhamnose by ThinLayer Chromatography.