title: Diverse Exopolysaccharide Producing Bacteria Isolated from Milled Sugarcane: Implications for Cane Spoilage and Sucrose Yield.
abstract: Bacterial deterioration of sugarcane during harvesting and processing is correlated with significant loss of sucrose yield and the accumulation of bacterial polysaccharides. Dextran, a homoglucan produced by Leuconostoc mesenteroides, has been cited as the primary polysaccharide associated with sugarcane deterioration. A culture-based approach was used to isolate extracellular polysaccharide (EPS) producing bacterial strains from milled sugarcane stalks. Ribosomal RNA sequencing analysis grouped 25 isolates into 4 genera. This study identified 2 bacterial genera not previously associated with EPS production or sucrose degradation. All isolates produced polysaccharide when grown in the presence of sucrose. Monosaccharide analysis of purified polymers by Gas Chromatography revealed 17 EPSs consisting solely of glucose (homoglucans), while the remainder contained traces of mannose or fructose. Dextranase treatment of polysaccharides yielded full digestion profiles for only 11 extracts. Incomplete hydrolysis profiles of the remaining polysaccharides suggest the release of longer oligosaccharides which may interfere with sucrose crystal formation.
authors.affiliation: Institute for Plant Biotechnology, Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
authors.forename: Stanton
authors.initials: S
authors.lastname: Hector
authors.affiliation: Institute for Plant Biotechnology, Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
authors.forename: Kyle
authors.initials: K
authors.lastname: Willard
authors.affiliation: LaunchLab, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
authors.forename: Rolene
authors.initials: R
authors.lastname: Bauer
authors.affiliation: Institute for Plant Biotechnology, Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
authors.forename: Inonge
authors.initials: I
authors.lastname: Mulako
authors.affiliation: Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.|Central Analytical Facility, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
authors.forename: Etienne
authors.initials: E
authors.lastname: Slabbert
authors.affiliation: Institute for Plant Biotechnology, Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
authors.forename: Jens
authors.initials: J
authors.lastname: Kossmann
authors.affiliation: Institute for Plant Biotechnology, Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
authors.forename: Gavin M
authors.initials: GM
authors.lastname: George
mesh_terms: D001419:Bacteria / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism*; D044822:Biodiversity; D003910:Dextranase / Q000378:metabolism; D055595:Mechanical Phenomena; D009005:Monosaccharides / Q000032:analysis; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D031786:Saccharum / Q000378:metabolism* / Q000382:microbiology*; D013395:Sucrose / Q000737:chemistry / Q000378:metabolism*
chemical_list: D009005:Monosaccharides; D011135:Polysaccharides, Bacterial; D013395:Sucrose; D003910:Dextranase