Improvement of Sodium Gluconate Production using a Thermo-tolerant Acetic Acid bacterium, Acetobacter Senegalensis
<strong>Introduction:</strong> Nowadays, gluconic acid and its derivatives usages have been broadening in food industry. However, there are still many studies to optimize the production of gluconic acid by fermentation methods. The main goal of the present study was to assess the influen...
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| Format: | Article |
| Language: | English |
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University of Isfahan
2019-06-01
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| Series: | Biological Journal of Microorganism |
| Subjects: | |
| Online Access: | http://bjm.ui.ac.ir/article_23577_17418e6d29d1a7beb8a278ce22228c68.pdf |
| Summary: | <strong>Introduction:</strong> Nowadays, gluconic acid and its derivatives usages have been broadening in food industry. However, there are still many studies to optimize the production of gluconic acid by fermentation methods. The main goal of the present study was to assess the influences of temperature and pH on some fermentation kinetic parameters and activity of total cellular dehydrogenase.
<strong>Materials and methods:</strong> <em>Acetobacter senegalensis </em>was cultured in batch mode fermentation in different conditions (different concentrations of carbohydrates, temperatures and pH<sub>s</sub>). In addition, the effect of pH onsub-population formation and by-product production was studied by flow cytometry and different chromatography techniques, respectively.
<strong>Results:</strong> Flow cytometric assessment showed that bacterial cells segregated during stationary phase, and two sub-populations were appeared based on the activity of total cellular dehydrogenases. Culture medium pH affected the sub-populations formation and the percentage of each sub-population. As culture medium pH decreased, higher percentage(up to 61% of inactive cells) were formed during stationary phase. In addition, it was proved that at low pH (4.5), the percentage of by-products such as keto-gluconic acids increased more than 6 times. Based on the obtained results, the optimum pH for <em>A. senegalensis</em> to ferment 95 g/L glucose to sodium gluconat at 38°C was 5-5.5.
<strong>Discussion and conclusion:</strong> <em>Acetobacter senegalensis</em> can be used as a potential microorganism to produce gluconic acid. However, cell segregation during fermentation seems to result in decreased active producing cells and decreased maximum glucose consumption rate. In future studies, it is necessary either to find a method to prevent cell population from segregation or to resuscitate them into functional cells. |
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| ISSN: | 2322-5173 2322-5181 |