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1 Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

1 2003

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Nowe, wielofunkcyjne biopolimery na bazie celulozy bakteryjnej i chitozanu

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Ciechańska D. , Struszczyk H. , Kazimierczak J.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

2003

tom Vol. 52, nr 25

413-415

There are some kinds of bacteria e.g. Acetobacter, Rhizobium, Agrobacter, known for their ability to produce cellulose extracellularity. A single cell can polymerize up to 200 000 glucose residues per second into a cellulose chain. Chemically, bacterial cellulose is identical with cellulose of plant origin and differs from latter only in supermolecular structure. Glucan chains of bacterial cellulose, transverse dimensions are about 3-4 x 100 nm and their length about 1-9 um [5]. Bacterial cellulose is characterised by high chemical purity, high crystallinity index (above 60%) and average polymerization degree of 2000-6000 [3]. Because of its structure composed of [Beta]- 1,4-glucan chains stabilised by extensive hydrogen bonding, bacterial cellulose is highly hydrophilic, has high absorption capability as well as very good mechanical parameters. Parameters of bacterial cellulose can be modified at the biosynthesis step, by addition of modifiers such as polyaminosaccharides (chitosan and its derivatives) to the culture medium [1,5]. Chemical modification of bacterial cellulose consist in building glucosoamine residues into glucan chains. The number of degraded chitosan segments introduced into glucan chains depends on type and quality of chitosan modifier and on culture conditions such as time, pH and temperature. Studies on bacterial cellulose biosynthesis are focused on application of that biopolymer in medicine as modern hydrogel wound dressings and in electronic industry as loudspeaker membranes.