title: Enhanced fructooligosaccharides and inulinase production by a Xanthomonas campestris pv. phaseoli KM 24 mutant.
abstract: Xanthomonas campestris pv phaseoli produced an extracellular endoinulinase (9.24 +/- 0.03 U mL(-1)) in an optimized medium comprising of 3% sucrose and 2.5% tryptone. X. campestris pv. phaseoli was further subjected to ethylmethanesulfonate mutagenesis and the resulting mutant, X. campestris pv. phaseoli KM 24 demonstrated inulinase production of 22.09 +/- 0.03 U mL(-1) after 18 h, which was 2.4-fold higher than that of the wild type. Inulinase production by this mutant was scaled up using sucrose as a carbon source in a 5-L fermenter yielding maximum volumetric (21,865 U L(-1) h(-1)) and specific (119,025 U g(-1) h(-1)) productivities of inulinase after 18 h with an inulinase/invertase ratio of 2.6. A maximum FOS production of 11.9 g L(-1) h(-1) and specific productivity of 72 g g(-1) h(-1) FOS from inulin were observed in a fermenter, when the mutant was grown on medium containing 3% inulin and 2.5% tryptone. The detection of mono- and oligosaccharides in inulin hydrolysates by TLC analysis indicated the presence of an endoinulinase. This mutant has potential for large-scale production of inulinase and fructooligosaccharides.
authors.affiliation: Faculty of Applied Sciences, Department of Biotechnology and Food Technology, Durban University of Technology, 1334, Durban, 4000, South Africa.
authors.forename: Kameshnee
authors.initials: K
authors.lastname: Naidoo
authors.forename: Manimaran
authors.initials: M
authors.lastname: Ayyachamy
authors.forename: Kugen
authors.initials: K
authors.lastname: Permaul
authors.forename: Suren
authors.initials: S
authors.lastname: Singh
mesh_terms: D024861:Genetic Enhancement; D007339:Insulysin / Q000378:metabolism*; D009154:Mutation; D009844:Oligosaccharides / Q000378:metabolism*; D013045:Species Specificity; D016959:Xanthomonas campestris / Q000145:classification / Q000235:genetics* / Q000378:metabolism*
chemical_list: D009844:Oligosaccharides; C116580:fructooligosaccharide; D007339:Insulysin