title: Studies on production of fructo-oligosaccharides (FOS) by gamma radiation processing of microbial levan.
abstract: Microbial levan, a natural polymer of fructose, was produced and purified by alcohol precipitation from culture supernatants of Bacillus megaterium type 1 grown in an optimized liquid sucrose medium. GPC analysis showed that the yield of the major fraction of levan having molecular weight ~5000 D increased with increase in sucrose concentration in the broth. Levan subjected to (60)Co-gamma radiation as well as acid hydrolysis was investigated by rheometry, UV-visible spectrophotometry and gel permeation chromatography (GPC) techniques. Unlike most of the polysaccharides, levan powder exhibited good radiation degradation stability up to 150 kGy. Gamma irradiation of 10% levan aqueous solution at 250 kGy yielded 63.0% fructo-oligosaccharide (FOS) with an average molecular weight of 1250 D. Acid hydrolysis of levan using 0.5 N HCl for 60 min treatment time gave rise to the desired FOS with lower yield (23.1%) as compared to that obtained in gamma radiolysis process.
authors.affiliation: Department of Microbiology, Bhavan's College, Andheri (W), Mumbai 400058, India.
authors.forename: N
authors.initials: N
authors.lastname: Jalan
authors.forename: Lalit
authors.initials: L
authors.lastname: Varshney
authors.forename: Nilanjal
authors.initials: N
authors.lastname: Misra
authors.forename: Jhimli
authors.initials: J
authors.lastname: Paul
authors.forename: D
authors.initials: D
authors.lastname: Mitra
authors.forename: D D
authors.initials: DD
authors.lastname: Rairakhwada
authors.forename: Z
authors.initials: Z
authors.lastname: Bhathena
authors.forename: Virendra
authors.initials: V
authors.lastname: Kumar
mesh_terms: D001410:Bacillus megaterium / Q000378:metabolism* / Q000528:radiation effects; D058491:Bacterial Load; D005630:Fructans / Q000096:biosynthesis / Q000528:radiation effects*; D005720:Gamma Rays; D009844:Oligosaccharides / Q000737:chemistry*; D010316:Particle Size; D014783:Viscosity
chemical_list: D005630:Fructans; D009844:Oligosaccharides; C072599:levan