ENZYMATICALLY PRODUCED CELLULOSE
Compositions are disclosed herein comprising cellulose that has (i) a weight-average degree of polymerization (DP w ) of about 10 to about 1000, (ii) a cellulose II crystal structure, and that is (iii) insoluble in an aqueous composition. Further disclosed are cellodextrin phosphorylase enzymes that synthesize this cellulose material. Methods of using cellulose for viscosity modification or film/coating applications are also disclosed.
1 . A composition comprising cellulose, wherein said cellulose:
(i) has a weight-average degree of polymerization (DP w ) of about 10 to about 1000,
(ii) has a cellulose II crystal structure, and
(iii) is insoluble in an aqueous composition.
2 . The composition of claim 1 , wherein the DP w of the cellulose is about 10 to about 100.
3 . The composition of claim 1 , wherein said cellulose is a product of a cellodextrin phosphorylase enzyme comprising an amino acid sequence that is at least 90% identical to SEQ ID NO:2 or SEQ ID NO:6, wherein the substrates for said enzyme comprise cellodextrin and glucose-1-phosphate.
4 . The composition of claim 3 , wherein the cellulose as produced by the enzyme has not been subjected to a mercerization or derivatization process.
5 . The composition of claim 1 , wherein the composition is a film or coating.
6 . The composition of claim 5 , wherein the film or coating has a uniform thickness of at least about 4 nm.
7 . The composition of claim 5 , wherein the film or coating exhibits low permeability to, or is impermeable to, an aqueous composition, lipophilic composition, or gaseous composition.
8 . The composition of claim 5 , wherein the film or coating is on paper.
9 . The composition of claim 1 , wherein the composition is an aqueous composition, optionally having a viscosity of at least about 100 cPs.
10 . The composition of claim 9 , wherein the aqueous composition is a colloidal dispersion.
11 . The composition of claim 9 , wherein the concentration of the cellulose in the aqueous composition is less than about 10 wt %.
12 . The composition of claim 9 , wherein the composition is a food product, personal care product, pharmaceutical product, household product, or industrial product.
13 . The composition of claim 1 , wherein the cellulose is soluble in a solvent comprising DMSO and/or DMAc.
14 . A method for increasing the viscosity of an aqueous composition, the method comprising:
contacting cellulose with the aqueous composition, wherein said cellulose is insoluble in the aqueous composition and has:
(i) a weight-average degree of polymerization (DP w ) of about 10 to about 1000, and
(ii) a cellulose II crystal structure,
wherein the viscosity of the aqueous composition is increased by said cellulose compared to the viscosity of the aqueous composition before the contacting step.
15 . The method of claim 14 , wherein the shear thinning behavior of the aqueous composition is increased by said cellulose compared to the shear thinning behavior of the aqueous composition before the contacting step.
16 . A method of treating a material, said method comprising:
(a) contacting a material with an aqueous composition comprising cellulose,
wherein the cellulose is insoluble in the aqueous composition and has:
(i) a weight-average degree of polymerization (DP w ) of about 10 to about 1000, and
(ii) a cellulose II crystal structure; and
(b) drying the aqueous composition,
wherein the drying step leaves a deposit of said cellulose on the surface of the material.