title: Small scale production and characterization of xanthan gum synthesized by local isolates of Xanthomonas campestris.
abstract: Xanthan gum is a commercially important microbial exopolysaccharide (EPS) produced by Xanthomonas campestris. X. campestris is a plant pathogen causing various plant diseases such as black rot of crucifers, bacterial leaf blight and citrus canker disease resulting in crop damage. In this study, we isolated efficient local bacterial isolates which are capable to produce xanthan gum utilizing different sources of carbon (maltose, sucrose and glucose). Bacterial isolates from different plant leaves and fruits were identified as Xanthomonas campestris based on their morphological and biochemical characteristics. Among the 23 isolates, 70% were capable of producing gum. Taro plant, considered as new bacterial host, also have the capability to produce xanthan gum. Production conditions of xanthan gum and their relative viscosity by these bacterial isolates were optimized using basal medium containing commercial carbon and nitrogen sources and various temperature and rotation. Highest level of xanthan gum (18.286 g/l) with relative viscosity (7.2) was produced (Host, Citrus macroptera) at 28 degrees C, pH 7.0, 150 rpm using sucrose as a carbon source at orbital shaker. Whereas, in lab fermenter, same conditions gave best result (19.587 g/l gum) with 7.8 relative viscosity. Chilled alcohol (96%) was used to recover the xanthan gum. FTIR studies also carried out for further confirmation of compatibility by detecting the chemical groups.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Barua
authors.forename: Md Jahangir
authors.initials: MJ
authors.lastname: Alam
authors.forename: Mohammad
authors.initials: M
authors.lastname: Salim
authors.forename: Tamzida Shamim
authors.initials: TS
authors.lastname: Ashrafee
mesh_terms: D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014774:Virulence; D016959:Xanthomonas campestris / Q000378:metabolism* / Q000472:pathogenicity
chemical_list: D011135:Polysaccharides, Bacterial; C002563:xanthan gum