초록 ▼

The present invention relates to a method to recover, purify and isolate polyhydroxyalkanoate (PHA) biopolymers from PHA-containing cell mass, which includes: (a) solubilizing the non-PHA cell mass in an acidic solution, leaving a suspension of partially crystallized PHA granules; (b) adjusting the

The present invention relates to a method to recover, purify and isolate polyhydroxyalkanoate (PHA) biopolymers from PHA-containing cell mass, which includes: (a) solubilizing the non-PHA cell mass in an acidic solution, leaving a suspension of partially crystallized PHA granules; (b) adjusting the pH of the suspension to 7-11 and separating the PHA solids from the dissolved non-PHA cellular mass; (c) re-suspending the PHA solids in a bleaching solution for decolorization; and (d) drying the resulting PHA solids. About 95% or greater of original PHA in cell mass is recovered, and the purity of PHA solids is about 97% or above. The weight average molecular mass of the purified biopolyesters is about 500 kDa or greater.

대표청구항 ▼

What is claimed is: 1. A method to recover, purify and modify polyhydroxyalkanoate (PHA) biopolymer solids from PHA-containing cells, which comprises the sequential steps of: (a) solubilizing non-PHA cell mass (NPCM) in an acidic solution, resulting in a suspension of partially crystallized PHA sol

What is claimed is: 1. A method to recover, purify and modify polyhydroxyalkanoate (PHA) biopolymer solids from PHA-containing cells, which comprises the sequential steps of: (a) solubilizing non-PHA cell mass (NPCM) in an acidic solution, resulting in a suspension of partially crystallized PHA solids; (b) adjusting the pH of the suspension to 7-11,-and separating the PHA solids from the dissolved NPCM by filtration or centrifugation; (c) resuspending the PHA solids in a bleaching solution for decolorization; and (d) drying the resulting PHA solids, wherein hydrogen ions (H+) released from an inorganic acid added to a slurry of PHA-containing cells are used to recover the PHA biopolymer solids from the PHA-containing cells. 2. The method as recited in claim 1, wherein the inorganic acid is sulfuric acid. 3. The method as recited in claim 1, wherein the concentration of hydrogen ion (H+) is 0.01 to 0.5 mole per liter. 4. The method as recited in claim 1, wherein the temperature of the acidic solution is 80-130° C. 5. The method as recited in claim 4, wherein the treatment time is 0.54-4 hours. 6. The method as recited in claim 1, wherein a base is added to the suspension of PHA solids. 7. The method as recited in claim 6, wherein the base is sodium hydroxide. 8. The method as recited in claim 5, wherein the pH of the suspension is adjusted to 7-10. 9. The method as recited in claim 1, wherein the bleaching solution comprises hypochlorite. 10. The method as recited in claim 1, wherein one part of hypochlorite is added per 0.5 to 10 parts of PHA solids. 11. The method as recited in claim 1, wherein the color of PHA solids is removed under ambient conditions. 12. The method as recited in claim 1, wherein the time for decolorization is 1 to 5 hours. 13. The method as recited in claim 1, wherein the PHA solids are dried at 60° C.-120° C. 14. The method as recited in claim 1, wherein the dried PHA solids are soluble in chloroform. 15. The method as recited in claim 1, wherein the purity of the PHA solids is about 97% or greater. 16. The method as recited in claim 1, wherein at least about 95% of PHA solids are recovered from the PHA-containing cells. 17. The method as recited in claim 1, wherein the PHA solids are biopolyesters. 18. The method as recited in claim 17, wherein the molecular weight of the biopolyesters is 500 kDa or greater.