This presentation is about production of Dextran from sucrose by using Leuconostoc Mesenteroides bacteria. First of all, the properties of dextran are discussed and then the production is explained through flowchart. The applications of dextran is also discussed in this presentation.

1. By -
Ishanee Sharma (15/252)
Nilim Kumar Sarma (15/256)
Dhritiman Bhuyan (15/263)
Department of Chemical Engineering
Assam Engineering College, Jalukbari

2. Dextran
 Branched poly-α-d-glucosides of microbial origin having glycosidic
bonds predominantly C-1 → C-6
 H(C6H10O5)xOH
 Chain length – 3 to 2000
kilodaltons; defined as Mw &
Mn
 Discovered by Louis Pasteur,
mass produced by Allen Jeanes
Fig. Structure of dextran

3. Properties
 Biodegradable
 Water soluble, as well as methyl sulphoxide, formamide, ethylene
glycol
 Produced by fermentation
1
 Stability ∝ Thermal conditions and branching
 Storable pH range – 4 to 10

4. Precipitator
Broth
Germ-free water
Methanol
Hydrolyzers
Filter and Wash
Crystallization
Mixing
Solution
Solids disposal
HCl
Filter aid
Methanol
Germ-free water
Methanol
recovery
Germ-free water
Production Microbe used: Leuconostoc
Mesenteroides
Medium: Sucrose

5. Ionizer
Evaporator
Filter
Spray Dryer
Dextran
Filter
Fig. Dextran manufacture

6. Applications
 1. In Medical field
• Dextran is used to decrease vascular thrombosis.
• It is occasionally used to replace lost blood in emergency
situations where replacement of blood is no available.
• The iron dextran solution is applied for treatment of human
anaemic deficiency.
 2. In food Industry
• Dextran improves softness, crum texture and loaf volume in
bakery products.
• Dextran is used as a stabilizer for confectionery as it prevents
crystallisation, increases viscosity and maintains flavour.

7. • Dextran prevents frozen foods from oxidation and also help to
preserve texture or flavour.
 3. Laboratory uses
• Fluorescently labelled dextran can be used to visualise
endosomes under a fluorescent microscope as it binds to early
endosomes.
• It can also be used as stabilising coating to potent nanoparticles
from oxidation and improve biocompatibility.
 4. Wastewater Treatment
• Dextran offers many useful features like stable alkali and acids. It
binds with metal ions in alkali pH and is biodegradable. It is used
during the flocculation process in wastewater treatment.