Separation of scleroglucan and cell biomass from Sclerotium glucanicum grown in an inexpensive, by-product based medium  

作　　者：Arlene Fosmer William Gibbons 

机构地区：[1]Biology&Microbiology Department,South Dakota State University,Brookings,South Dakota 57007 USA

出　　处：《International Journal of Agricultural and Biological Engineering》2011年第1期52-60,共9页国际农业与生物工程学报（英文）

基　　金：supported by the South Dakota Corn Utilization Council and by the South Dakota Agricultural Experiment Station,grant no.SD00151-H.

摘　　要：Scleroglucan is an extracellular polysaccharide produced by the fungi Sclerotium.Scleroglucan is stable over a broad range of temperatures,pH and salt concentration,thus having great potential in many diverse applications.Common media for scleroglucan production contain expensive components,such as yeast extract,that make the medium cost-ineffective for some industrial applications.Thus we developed a medium which uses Condensed Corn Solubles(CCS),a nutrient-rich byproduct of corn-based ethanol production,to replace expensive components.Methods typically used to recover scleroglucan are also expensive,and can limit commercialization.To evaluate alternative processes for scleroglucan recovery,we prepared scleroglucan in a modified version of Wang’s medium and a CCS-glucose medium.Broth samples were initially subjected to the standard recovery method to develop a complete mass balance,and then we evaluated various treatments to improve scleroglucan recovery.These included heat treatments to lyse cells,using different alcohol precipitants,freezing or refrigerating before recovery,and diluting broth to enhance cell separation.The CCS medium produced 14.2 g/L scleroglucan,compared to 10.1 g/L in the modified Wang’s medium.Based on the standard recovery protocol,we determined that 96%of the scleroglucan was recovered from the initial centrifugation and precipitation.Washing the cell pellet with water and recentrifuging only recovered a minimal amount of scleroglucan,and thus it could be eliminated from protocol to save energy and costs.Lysing cells by boiling or autoclaving did not release more scleroglucan than un-heated samples,and we also found no statistical difference between ethanol,isopopanol,and methanol as scleroglucan precipitants.Refrigerating the broth prior to scleroglucan recovery had no significant effect,while freezing actually decreased scleroglucan recovery.Initially diluting the broth by 0.50 or 0.34 resulted in the greatest scleroglucan recovery,while higher or lower dilutions decreased recovery

关 键 词：SCLEROGLUCAN Sclerotium glucanicum exopolysaccharide separation condensed corn solubles 

分 类 号：Q53[生物学—生物化学]