Screening Of Marine Microorganisms Producing Extracellular Polysaccharides And Researching Of Fermentation Conditions

With the development of suger chemistry、glycobiology、glucose engineering，peoplehave recognized that polysaccharides have important function in biological． Marinemicroorganism can always produce special products what is different from land due to marineeco-environment’s high salt、high pressure、low temperature and special illumination．Atpresent，marine microorganisms have receive much concern because of their stable structureand function、 inexpensive price and short production cycle． In this paper， marinemicroorganism that can produce extracellular polysaccharides were screened from marinesoil，marine algae and sea water．Their growth characters，fermentation conditions wereresearched，and strains also have been preliminary identified．In this paper，139strains that can produce extracellular polysaccharides werescreened．Two of them were high yield，so denominate them S-10、S-12．Their culturalcharacteristics、cell morphology、physiological and biochemical characteristics were analysedand studied．Based on identification，the strain S-10is steady bacillus and S-12is bacillus．In this article，the growth character of strain S-10and strain S-12can be studied bymeasuring biomass．Their initial pH value of medium were pH7.0and pH6.0respectively，tolerance of salinity were4%and3%．They could produce extracellular polysaccharides wellin the sea-water medium；Through determining extracellular polysaccharide content byphenol-sulfuric acid method，better culture condition of marine microorganism strain S-10andS-12what produce extracellular polysaccharides respectively were：temperature30℃、liquid-installed30mL/100mL、inoculate quantity10%、shaking speed120r/min；temperature30℃、liquid-installed40mL/100mL、inoculate quantity10%、shaking speed140r/min．Underthese conditions， the yield of extracellular polysaccharides were564.9mg/100mL and445.5mg/100mL， respectively； raw polysaccharides yield were58.1%and54.2%，respectively．Molecular weight were preliminary measured by using viscosimetry，they were14167Da、23548Da, respectively．...