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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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The effects of various culture constituents on HZ-7 production.A, inoculum size (%); B, seed age (h); C, medium volume (mL); D, agitation rate (rpm); E, initial pH; F, incubation temperature (°C). Each bar represented the mean± SD of three replicates.
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pone-0053542-g004: The effects of various culture constituents on HZ-7 production.A, inoculum size (%); B, seed age (h); C, medium volume (mL); D, agitation rate (rpm); E, initial pH; F, incubation temperature (°C). Each bar represented the mean± SD of three replicates.

Mentions: Seed age and inoculum size were the two crucial biological parameters to be optimized. These experiment parameters generally affected the length of the lag phase. In order to a healthy inoculum, different seed ages (6, 9, 12, 15 and 18 h) were used. Maximum HZ-7 (13.31 g/L) was obtained with 15-h-old inoculum (Figure 4A). Similarly the fermentation medium was inoculated with different inoculum sizes of 5, 8, 10, 12 and 15% v/v and the results are shown in Figure 4B. Maximum yield of HZ-7 (13.63 g/L) was achieved with 12% (v/v) of 15 h old inoculum. General studies have been carried out using 10% (v/v) 24-h-old inoculums [27], [28].


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)

The effects of various culture constituents on HZ-7 production.A, inoculum size (%); B, seed age (h); C, medium volume (mL); D, agitation rate (rpm); E, initial pH; F, incubation temperature (°C). Each bar represented the mean± SD of three replicates.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0053542-g004: The effects of various culture constituents on HZ-7 production.A, inoculum size (%); B, seed age (h); C, medium volume (mL); D, agitation rate (rpm); E, initial pH; F, incubation temperature (°C). Each bar represented the mean± SD of three replicates.
Mentions: Seed age and inoculum size were the two crucial biological parameters to be optimized. These experiment parameters generally affected the length of the lag phase. In order to a healthy inoculum, different seed ages (6, 9, 12, 15 and 18 h) were used. Maximum HZ-7 (13.31 g/L) was obtained with 15-h-old inoculum (Figure 4A). Similarly the fermentation medium was inoculated with different inoculum sizes of 5, 8, 10, 12 and 15% v/v and the results are shown in Figure 4B. Maximum yield of HZ-7 (13.63 g/L) was achieved with 12% (v/v) of 15 h old inoculum. General studies have been carried out using 10% (v/v) 24-h-old inoculums [27], [28].

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