Synthesis and Physico-Chemical Analysis of Dextran from Maltodextrin via pH Controlled Fermentation by <i>Gluconobacter oxydans</i>
Dextran is an exopolysaccharide (EPS) with multifunctional applications in the food and pharmaceutical industries, primarily synthesized from <i>Leuconostoc mesenteroides</i>. Dextran can be produced from dextrin through <i>Gluconobacter oxydans</i> fermentation, utilizing it...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
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| Series: | Foods |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2304-8158/14/1/85 |
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| Summary: | Dextran is an exopolysaccharide (EPS) with multifunctional applications in the food and pharmaceutical industries, primarily synthesized from <i>Leuconostoc mesenteroides</i>. Dextran can be produced from dextrin through <i>Gluconobacter oxydans</i> fermentation, utilizing its dextran dextrinase activity. This study examined how jar fermentor conditions impact the growth and enzyme activity of <i>G. oxydans</i>, with a focus on the effects of pH on dextran synthesis via bioconversion (without pH control, pH 4.5, and pH 5.0; Jp-UC, Jp-4.5, and Jp-5.0). After 72 h, the cell density (O.D. at 600 nm) was 7.2 for Jp-4.5, 6.5 for Jp-5.0, and 3.7 for Jp-UC. Flow property analysis, indicating dextran production, showed that Jp-4.5 had the highest viscosity (30.99 mPa·s). <sup>1</sup>H-NMR analysis confirmed the formation of α-1,6 glycosidic bonds in bioconversion products, with bond ratios ranging from ~1:0.17 to ~1:2.84. The distribution of molecular weights varied from 1.3 × 10<sup>3</sup> Da to 5.1 × 10<sup>4</sup> Da depending on pH. The hydrolysis rates to glucose differed with pH, with the slowest rate at pH 4.5 (53.96%). These results suggest that the production of dextran by <i>G. oxydans</i> is significantly influenced by the pH conditions. This dextran could function as a slowly digestible carbohydrate, aiding in postprandial glycemic regulation and mitigating chronic metabolic diseases like diabetes. |
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| ISSN: | 2304-8158 |