title: Isolation and physico-chemical characterisation of extracellular polymeric substances produced by the marine bacterium Vibrio parahaemolyticus.
abstract: A marine bacterial strain identified as Vibrio parahaemolyticus by 16S rRNA gene (HM355955) sequencing and gas chromatography (GC) coupled with MIDI was selected from a natural biofilm by its capability to produce extracellular polymeric substances (EPS). The EPS had an average molecule size of 15.278 μm and exhibited characteristic diffraction peaks at 5.985°, 9.150° and 22.823°, with d-spacings of 14.76661, 9.29989 and 3.89650 Å, respectively. The Fourier-transform infrared spectroscopy (FTIR) spectrum revealed aliphatic methyl, primary amine, halide groups, uronic acid and saccharides. Gas chromatography mass spectrometry (GCMS) confirmed the presence of arabinose, galactose, glucose and mannose. (1)HNMR (nuclear magnetic resonance) revealed functional groups characteristic of polysaccharides. The EPS were amorphous in nature (CI(xrd) 0.092), with a 67.37% emulsifying activity, thermostable up to 250°C and displayed pseudoplastic rheology. MALDI-TOF-TOF analysis revealed a series of masses, exhibiting low-mass peaks (m/z) corresponding to oligosaccharides and higher-mass peaks for polysaccharides consisting of different ratios of pentose and hexose moieties. This is the first report of a detailed characterisation of the EPS produced by V. parahaemolyticus, which could be further explored for biotechnological and industrial use.
authors.affiliation: Discipline of Marine Biotechnology and Ecology, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research, Bhavnagar, Gujarat, India.
authors.forename: Kumari
authors.initials: K
authors.lastname: Kavita
authors.forename: Avinash
authors.initials: A
authors.lastname: Mishra
authors.forename: Bhavanath
authors.initials: B
authors.lastname: Jha
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification; D018441:Biofilms; D057219:Biofouling; D045703:Emulsifying Agents / Q000737:chemistry / Q000302:isolation & purification; D005110:Extracellular Space / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D019906:Nuclear Magnetic Resonance, Biomolecular; D009696:Nucleic Acids / Q000737:chemistry / Q000302:isolation & purification; D010316:Particle Size; D010743:Phospholipids / Q000737:chemistry / Q000302:isolation & purification; D011108:Polymers / Q000737:chemistry* / Q000302:isolation & purification; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017550:Spectroscopy, Fourier Transform Infrared; D014736:Vibrio parahaemolyticus / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D001426:Bacterial Proteins; D045703:Emulsifying Agents; D009696:Nucleic Acids; D010743:Phospholipids; D011108:Polymers; D011135:Polysaccharides, Bacterial