Chitooligosaccharides--preparation with the aid of pectinase isozyme from Aspergillus niger and their antibacterial activity.
An isozyme of pectinase from Aspergillus niger with polygalacturonase activity caused chitosanolysis at pH 3.5, resulting in low-molecular weight chitosan (86%), chitooligosaccharides (COs, 4.8%) and monomers (2.2%). HPLC showed the presence of COs with DP ranging from 2 to 6. Charcoal-Celite chromatography and re-N-acetylation of the COs followed by CD, IR, MALDI-TOF-MS and FAB-MS analyses revealed an abundance of chitobiose, chitotriose and chitotetraose. The COs-monomeric mixture showed a bactericidal effect towards Bacillus cereus and Escherichia coli more efficiently than native chitosan. Among the chitooligomers, the hexamer showed maximum antibacterial effect followed by the penta-, tetra-, tri- and dimers. Of the two monomers, only GlcN showed slight bacterial growth inhibition. SEM revealed bactericidal action patterns of COs-monomeric mixture towards B. cereus and E. coli.
Kittur
Farooqahamed S
FS
Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Mysore 570 020, India.
Vishu Kumar
Acharya B
AB
Varadaraj
Mandyam C
MC
Tharanathan
Rudrapatnam N
RN
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D001234:Aspergillus niger / Q000201:enzymology*; D001409:Bacillus cereus / Q000187:drug effects / Q000648:ultrastructure; D048271:Chitosan / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D004926:Escherichia coli / Q000187:drug effects / Q000648:ultrastructure; D007527:Isoenzymes / Q000378:metabolism; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D011096:Polygalacturonase / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared
D000900:Anti-Bacterial Agents; D007527:Isoenzymes; D009844:Oligosaccharides; D048271:Chitosan; D011096:Polygalacturonase