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Optimization of fermentation conditions and properties of an exopolysaccharide from Klebsiella sp. H-207 and application in adsorption of hexavalent chromium.

Qiang L, Yumei L, Sheng H, Yingzi L, Dongxue S, Dake H, Jiajia W, Yanhong Q, Yuxia Z - PLoS ONE (2013)

Bottom Line: The resulting product showed good properties, such as high concentration of uronic acid (41.67%), low average molecular weight (about 1.94×10(5) Da) and porous surface structure, were very advantageous to biosorption.Therefore HZ-7 was applied to absorb hexavalent chromium (Cr(VI)).These data suggest Klebsiella sp.

View Article: PubMed Central - PubMed

Affiliation: School of Medicine and Life Sciences, University of Jinan, Jinan, China. chm_ lq@ujn.edu.cn

ABSTRACT
The novel exopolysaccharide HZ-7 is produced by Klebsiella sp. H-207, and its fermentation conditions were optimized by response surface methodology (RSM). In this study, the optimized medium consisted of sucrose 31.93 g/L, KNO(3) 2.17 g/L and K(2)HPO(4) 5.47 g/L; while the optimized culture conditions consisted of seed age 13 h, with an inoculum size of 10.6% and incubation temperature of 28.9°C. A maximum HZ-7 yield of about 15.05 g/L was achieved under the optimized conditions using RSM and single-factor experiments. Next the exopolysaccharide HZ-7 was partially purified and characterized. The resulting product showed good properties, such as high concentration of uronic acid (41.67%), low average molecular weight (about 1.94×10(5) Da) and porous surface structure, were very advantageous to biosorption. Therefore HZ-7 was applied to absorb hexavalent chromium (Cr(VI)). The maximum adsorption efficiency (99.2%) which was obtained at an initial pH of 1.0 along with an initial Cr(VI) concentration of 20 mg/L, was not affected by ordinary metal ions and temperature. These data suggest Klebsiella sp. H-207 exopolysaccharide will be promising potential for industrial application.

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Response surface plots of the effect of three variables for culture conditions on HZ-7 production.A, interaction of temperature (X1, °C) and seed age (X2, h); B, interaction of temperature (X1, °C) and inoculum size (X3, %); C, interaction of seed age (X2, h) and inoculum size (X3, %).
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pone-0053542-g005: Response surface plots of the effect of three variables for culture conditions on HZ-7 production.A, interaction of temperature (X1, °C) and seed age (X2, h); B, interaction of temperature (X1, °C) and inoculum size (X3, %); C, interaction of seed age (X2, h) and inoculum size (X3, %).

Mentions: The fit of the model was verified by the determination of R2, which was 0.9964 for HZ-7 production, indicating that 99% of the variability in the response could be explained by this model. As shown in Table 4, the ‘Model F-value’ of 212.84 and the CV of 1.62% indicated that the model was significant. Due to less than 0.05 of P values, X1 and X2 were significant model terms. Moreover, the interactions between each pair of the three variables were significant, which was well supported by the fact that their strong interaction increased HZ-7 production by about 15 g/L (Figure 5A, B, C). Based on the canonical analysis, the optimal conditions of inoculum size, seed age and incubation temperature were 10.6%, 13 h and 28.9°C, respectively. The maximum yield was estimated to be 15.04 g/L, and the actual yield under the optimal fermentation conditions was 15.05 g/L, which was the average value of three experiments.


Optimization of fermentation conditions and properties of an exopolysaccharide from Klebsiella sp. H-207 and application in adsorption of hexavalent chromium.

Qiang L, Yumei L, Sheng H, Yingzi L, Dongxue S, Dake H, Jiajia W, Yanhong Q, Yuxia Z - PLoS ONE (2013)

Response surface plots of the effect of three variables for culture conditions on HZ-7 production.A, interaction of temperature (X1, °C) and seed age (X2, h); B, interaction of temperature (X1, °C) and inoculum size (X3, %); C, interaction of seed age (X2, h) and inoculum size (X3, %).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3539975&req=5

pone-0053542-g005: Response surface plots of the effect of three variables for culture conditions on HZ-7 production.A, interaction of temperature (X1, °C) and seed age (X2, h); B, interaction of temperature (X1, °C) and inoculum size (X3, %); C, interaction of seed age (X2, h) and inoculum size (X3, %).
Mentions: The fit of the model was verified by the determination of R2, which was 0.9964 for HZ-7 production, indicating that 99% of the variability in the response could be explained by this model. As shown in Table 4, the ‘Model F-value’ of 212.84 and the CV of 1.62% indicated that the model was significant. Due to less than 0.05 of P values, X1 and X2 were significant model terms. Moreover, the interactions between each pair of the three variables were significant, which was well supported by the fact that their strong interaction increased HZ-7 production by about 15 g/L (Figure 5A, B, C). Based on the canonical analysis, the optimal conditions of inoculum size, seed age and incubation temperature were 10.6%, 13 h and 28.9°C, respectively. The maximum yield was estimated to be 15.04 g/L, and the actual yield under the optimal fermentation conditions was 15.05 g/L, which was the average value of three experiments.

Bottom Line: The resulting product showed good properties, such as high concentration of uronic acid (41.67%), low average molecular weight (about 1.94×10(5) Da) and porous surface structure, were very advantageous to biosorption.Therefore HZ-7 was applied to absorb hexavalent chromium (Cr(VI)).These data suggest Klebsiella sp.

View Article: PubMed Central - PubMed

Affiliation: School of Medicine and Life Sciences, University of Jinan, Jinan, China. chm_ lq@ujn.edu.cn

ABSTRACT
The novel exopolysaccharide HZ-7 is produced by Klebsiella sp. H-207, and its fermentation conditions were optimized by response surface methodology (RSM). In this study, the optimized medium consisted of sucrose 31.93 g/L, KNO(3) 2.17 g/L and K(2)HPO(4) 5.47 g/L; while the optimized culture conditions consisted of seed age 13 h, with an inoculum size of 10.6% and incubation temperature of 28.9°C. A maximum HZ-7 yield of about 15.05 g/L was achieved under the optimized conditions using RSM and single-factor experiments. Next the exopolysaccharide HZ-7 was partially purified and characterized. The resulting product showed good properties, such as high concentration of uronic acid (41.67%), low average molecular weight (about 1.94×10(5) Da) and porous surface structure, were very advantageous to biosorption. Therefore HZ-7 was applied to absorb hexavalent chromium (Cr(VI)). The maximum adsorption efficiency (99.2%) which was obtained at an initial pH of 1.0 along with an initial Cr(VI) concentration of 20 mg/L, was not affected by ordinary metal ions and temperature. These data suggest Klebsiella sp. H-207 exopolysaccharide will be promising potential for industrial application.

Show MeSH
Related in: MedlinePlus