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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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Scanning electron microphotograph of HZ-7L.
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pone-0053542-g006: Scanning electron microphotograph of HZ-7L.

Mentions: The infrared spectrum of HZ-7L displayed a broad and intense stretching peak at 3425 cm−1, characteristic of hydroxyl groups, C–H stretching band at 2920 cm−1, an asymmetrical stretching band at 1724 cm−1, and a symmetrical stretching band at 1616 cm−1 was characteristic of C = O stretching vibration. The absorption peak at 1053 cm−1 is characteristic for all sugar derivatives. Since the specialization of absorption peak at 1650 cm−1 was not seen, we can conclude that there is no amino sugar, which is in accordance with the element analysis for N and chemical detection for amino sugar. The scanning electron microscopy observations (Figure 6) indicate that the surface morphology of HZ-7L is a porous structure with randomly distributed small pores and interconnected channels, which makes its specific surface area larger and more beneficial for biosorption.


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)

Scanning electron microphotograph of HZ-7L.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0053542-g006: Scanning electron microphotograph of HZ-7L.
Mentions: The infrared spectrum of HZ-7L displayed a broad and intense stretching peak at 3425 cm−1, characteristic of hydroxyl groups, C–H stretching band at 2920 cm−1, an asymmetrical stretching band at 1724 cm−1, and a symmetrical stretching band at 1616 cm−1 was characteristic of C = O stretching vibration. The absorption peak at 1053 cm−1 is characteristic for all sugar derivatives. Since the specialization of absorption peak at 1650 cm−1 was not seen, we can conclude that there is no amino sugar, which is in accordance with the element analysis for N and chemical detection for amino sugar. The scanning electron microscopy observations (Figure 6) indicate that the surface morphology of HZ-7L is a porous structure with randomly distributed small pores and interconnected channels, which makes its specific surface area larger and more beneficial for biosorption.

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