Effect of carbon sources on xanthan production by Xanthomonas spp. isolated from pepper leaves

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.

Screening of Local Wild Xanthomonas Species for Xanthan Production on Crude Glycerol-based Medium

“…On the other side, the results presented in Table 1 also show that producing strain and combination of producing strain and cultivation time have a statistically significant effect on xanthan concentration in cultivation media when biosynthesis is performed by X. euvesicatoria strains isolated from pepper leaves (p < 0.05). This result is in accordance with previous research findings where it is confirmed that selection of Xanthomonas strains isolated from pepper leaves have statistically significant effect on xanthan concentration in media [13]. However, if attention is paid to the mean square values presented in the same table, it can be concluded that the combination of producing strain and cultivation time has a greater effect on this group of results for xanthan concentration in media, while the effect of X. euvesicatoria strains is lower.…”

“…The chemical structure of this biopolymer is composed of glucose, mannose and glucuronic acid units and its molecular weight usually ranges from 2 × 10 5 g/moL to 2 × 10 7 g/moL [11,12]. Commercial production of xanthan is generally conducted by aerobic submerged batch cultivation of reference strain Xanthomonas campestris ATCC 13951 on the appropriate medium under optimal conditions [13]. Glucose and sucrose are most commonly used carbon sources in cultivation media for xanthan production but rise in prices and the growing demand for mentioned sugars indicate that more economical carbon sources are needed in order to reduce the overall production costs [14].…”

Xanthan Production Using Wastewaters from Rose Wine Industry: Screening of Xanthomonas euvesicatoria Isolates

“…The results presented in Table 2 show that the p-values for all analyzed parameters are much lower than 0.05, which indicates that applied X. euvesicatoria isolates have a statistically significant effect on the xanthan concentration in cultivation medium, its molecular weight, as well as on apparent viscosity of the xanthan aqueous solution. These results are in accordance with previous research findings where xanthan production was performed by Xanthomonas strains isolated from pepper leaves on the media with different carbon sources (glucose, lactose and starch), and it is confirmed that selection of producing microorganism have statistically significant effect on xanthan concentration in media and apparent viscosity of its aqueous solution [38]. Moreover, findings from this study are in agreement with results from another previous research where Xanthomonas strains isolated from pepper leaves were cultivated on the medium containing glucose, commercial glycerol and crude glycerol from biodiesel industry, and it is also confirmed that variation of Xanthomonas strains have statistically significant effect on xanthan quantity and its molecular weight [39,40].…”

Eco-friendly Modified Biopolymers for Enhancing Oil Production: A Review

“…Consequently, a pentasaccharide is the main repeating structure. The mannose at the end of the branch has a pyruvate group, while the mannose next to the backbone has an acetyl group linked to C 6 [27][28][29]. Thus, the glucuronic and pyruvic acid groups are accountable for the extremely negative charge of this natural polymer.…”