title: Alginate-deriving oligosaccharide production by alginase from newly isolated Flavobacterium sp. LXA and its potential application in protection against pathogens.
abstract: OBJECTIVE
  To examine algino-oligosaccharide production by alginase from newly isolated Flavobacterium sp. LXA and its elicitor and antibacterial activity.
  
  
  RESULTS
  Algino-oligosaccharide production from alginate was carried out using alginase obtained from a newly isolated Flavobacterium sp. LXA. When alginase was partially purified by dual ammonium sulfate precipitation and used for alginate degradation, the viscosity loss correlated well with the release of reducing terminals. The optimal temperature and pH for alginate degradation was 40 degrees C and pH 7.0, respectively. When alginate was added at an initial concentration of more than 0.8%, the maximal degradation rate of alginate was obtained. Under these optimal reaction conditions and with partially purified alginase, the average degrees of polymerization (DP) of alginate-degraded products was about 6.0, which favoured algino-oligosaccharide production. The algino-oligosaccharides showed an elicitor activity stimulating the accumulation of phytoalexin and inducing phenylalanine ammonia lyase in soybean cotyledon, and antimicrobial activity on Pseudomonas aeruginosa.
  
  
  CONCLUSIONS
  Algino-oligosaccharide could be degraded from alginate by the partially purified alginase and its maximal bioactivity occurred on the oligosaccharide with average DP 6.8.
  
  
  CONCLUSIONS
  Algino-oligosaccharide was first reported to have elicitor and antibacterial activity and have potential as a biological agent for protection against plant or human disease.
authors.affiliation: Department of Chemical and Material Engineering, Dalian College of Light Industry, Dalian, PR China.
authors.forename: Q-D
authors.initials: QD
authors.lastname: An
authors.forename: G-L
authors.initials: GL
authors.lastname: Zhang
authors.forename: H-T
authors.initials: HT
authors.lastname: Wu
authors.forename: Z-C
authors.initials: ZC
authors.lastname: Zhang
authors.forename: G-S
authors.initials: GS
authors.lastname: Zheng
authors.forename: L
authors.initials: L
authors.lastname: Luan
authors.forename: Y
authors.initials: Y
authors.lastname: Murata
authors.forename: X
authors.initials: X
authors.lastname: Li
mesh_terms: D000464:Alginates / Q000378:metabolism* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D018548:Cotyledon / Q000187:drug effects; D005417:Flavobacterium / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D009844:Oligosaccharides / Q000378:metabolism* / Q000494:pharmacology; D011133:Polysaccharide-Lyases / Q000032:analysis / Q000302:isolation & purification; D013025:Glycine max; D013696:Temperature
chemical_list: D000464:Alginates; D000900:Anti-Bacterial Agents; D009844:Oligosaccharides; D011133:Polysaccharide-Lyases; C016158:poly(beta-D-mannuronate) lyase