PoIi(3-hidroksibulirat-c0-4-hidroksibulirat) daripada bacteria pencilan tempatan
| dc.contributor.author | Amirul AI-Ashraf Abdullah | |
| dc.date.accessioned | 2017-08-02T07:34:54Z | |
| dc.date.available | 2017-08-02T07:34:54Z | |
| dc.date.issued | 2007 | |
| dc.description.abstract | A Gram negative bacterium, Cupriavidus sp. USMAA 1020 with an ability to produce poly(3- hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] when grown on y-butyrolactone as the sole carbon source was isolated from Malaysian environment. It accumulated P(3HB-co-4HB) copolyester with a higher 4HB fraction (53 mol%) when grown in a nitrogen-free mineral medium containing y-butyrolactone through a two-step cultivation process. The biosynthesis of P(3HB-co- 4HB) was also achieved by using 4-hydroxybutyric acid and alkanediols with even carbon numbers such as 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,1 O-decanediol, and 1, 12-dodecanediol. The composition of copolyesters varied from 10 to 51 mol% 4HB, depending on the carbon sources supplied. When y-butyrolactone was used as the sole carbon source, the 4HB fraction in copolyester increased from 25 to 60 mol% as the concentration of y-butyrolactone in the culture medium was increased. However, this lowered the P(3HB-co-4HB) content and molecular weight significantly. Manipulating the culture conditions were affected the production of P(3HB-co-4HB) and 4HB composition. P(3HB-co-4HB) copolymer with 4HB compositions ranging from 23 to 75 mol% 4HB were successfully produced by varying the medium aeration. The physical and mechanical properties of P(3HB-co-4HB) copolymers were characterized by NMR spectroscopy, gel-permeation chromatography, and tensile test. The number-average molecular weights (Mn) of copolymers ranged from 260 x 103 to 590 X 103 Dalton, and the polydispersities (M~n) were between 1.8 and 3.0. Increases in the 4HB composition lowered the molecular weight of these copolymers. The P(3HB-c0-4HB) copolymers exhibit a wide variety of characteristics from crystalline thermoplastic to strong elastomer when 4HB composition increases. In addition, the increase in 4HB composition affected the randomness of copolymer, tensile strength, and elongation to break. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/4295 | |
| dc.title | PoIi(3-hidroksibulirat-c0-4-hidroksibulirat) daripada bacteria pencilan tempatan | en_US |
| dc.type | Technical Report | en_US |
Files
License bundle
1 - 1 of 1
Loading...
- Name:
- license.txt
- Size:
- 1.71 KB
- Format:
- Item-specific license agreed upon to submission
- Description: