رسالة جامعية
Process development for mannitol production by lactic acid bacteria
| العنوان: | Process development for mannitol production by lactic acid bacteria |
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| المؤلفون: | Weymarn, Niklas |
| المساهمون: | Department of Chemical Technology, Kemian tekniikan osasto, Laboratory of Bioprocess Engineering, Bioprosessitekniikan laboratorio, Aalto-yliopisto, Aalto University |
| بيانات النشر: | Helsinki University of Technology Teknillinen korkeakoulu |
| سنة النشر: | 2002 |
| المجموعة: | Aalto University Publication Archive (Aaltodoc) / Aalto-yliopiston julkaisuarkistoa |
| مصطلحات موضوعية: | Biotechnology, D-mannitol, mannitol dehydrogenase, Lactobacillus, Leuconostoc, membrane cell-recycle bioreactor, resting cells, metabolic engineering, lactate dehydrogenase, acetate kinase, fructokinase, L-lactate, pyruvate |
| الوصف: | D-Mannitol (here: mannitol) is a naturally occurring sugar alcohol with six carbon atoms. It is only half as sweet as sucrose. However, mannitol and other sugar alcohols exhibit reduced caloric values compared to the respective value of most sugars, which make them applicable as sweeteners in so-called "light" foods. Moreover, sugar alcohols are metabolized independently of insulin and are thus also applicable in diabetic food products. Besides applications in the food industry, mannitol is also used in the pharmaceutical industry. In medicine, mannitol is used to decrease cellular edema (excessive accumulation of fluid) and increases the urinary output. In this doctoral thesis, the development of a new bioprocess for the production of mannitol is described. For this purpose, aspects such as strain selection, choice of process method, optimization of process parameters, scale-up, and metabolic engineering were studied. At present, mannitol is produced commercially by catalytic hydrogenation of fructose-containing syrups. The existing chemical production methods are, however, characterized by several drawbacks. The uppermost being that when fructose is catalytically hydrogenated only about 50 % of it is converted into mannitol, whereas the rest is converted into another sugar alcohol, sorbitol. In addition, ultra-pure (expensive) raw materials (fructose and hydrogen gas) are required for efficient conversion. When more cost-effective raw materials, such as glucose-fructose syrups are used as starting material for catalytic hydrogenation, the main product is sorbitol and mannitol is formed as a by-product. Hence, mannitol production becomes very dependent on the market demand of sorbitol. Furthermore, mannitol is relatively difficult to purify from sorbitol. In addition, ion exchange is required for removal of the metal catalyst from the production solution. This results in even higher production costs and decreased yields. The microbial mannitol production process described in this thesis is based on high cell ... |
| نوع الوثيقة: | doctoral or postdoctoral thesis |
| وصف الملف: | application/pdf |
| اللغة: | English |
| ردمك: | 978-951-22-5885-7 951-22-5885-4 |
| تدمد: | 0359-6621 |
| العلاقة: | Technical biochemistry report; 1/2002; Teknillisen biokemian tiedote; 951-22-5885-4; https://aaltodoc.aalto.fi/handle/123456789/2167Test; urn:nbn:fi:tkk-001370 |
| الإتاحة: | https://aaltodoc.aalto.fi/handle/123456789/2167Test |
| رقم الانضمام: | edsbas.EB7901B |
| قاعدة البيانات: | BASE |
| ردمك: | 9789512258857 9512258854 |
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| تدمد: | 03596621 |