ABSTRACT

Xanthan is the most important microbial exopolysaccharide used in different branches of food and non-food industry. Due to high consumption of glucose and sucrose, usually utilized carbon sources in many bioprocesses, the most prominent research  in xanthan production is related to the isolation of new xanthan producing strains capable to metabolize other carbon sources and to produce xanthan  with  characteristics  appropriate  for  usage  in  food  industry.  The  aim  of  this  study  was  to examine  the  effect  of  variation  of  carbon  sources  in  cultivation  media  on  xanthan  production  by reference strain Xanthomonas campestris ATCC 13951 and five Xanthomonas strains isolated from infected  pepper  leaves.  Bioprocess  efficacy  was  estimated  based  on  the  quantity  and  quality  of biosynthesized xanthan. The obtained results show that both, the selection of the carbon source and selection of producing strain have a statistically significant effect on bioprocess efficacy whereby the influence of carbon sources on the analyzed parameters is more pronounced. It was confirmed that Xanthomonas strains responsible for the production of a large amount of xanthan are not suitable for biosynthesis of good-quality biopolymer. Taking into account all results it can be concluded that the greatest potential in biotechnological xanthan production has strain PFNS PL4 and glucose or starch containing media which is the basis for further research.