Characterisation Of Polyhydroxyalkanoate Synthesis
Polyhydroxyalkanoate (PHA) is a biodegradable and renewable thermoplastic that has potential to replace synthetic petroleum-based plastic due to their similar properties. Azotobacter vinelandii, a Gram-negative soil bacterium, is one of the microbes that can produce PHA. Many studies have been carri...
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| Format: | Thesis |
| Language: | English |
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2019
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| Online Access: | http://eprints.usm.my/56170/ http://eprints.usm.my/56170/1/MOK%20PEI%20SHZE24.pdf |
| _version_ | 1848883281625350144 |
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| author | Mok, Pei Shze |
| author_facet | Mok, Pei Shze |
| author_sort | Mok, Pei Shze |
| building | USM Institutional Repository |
| collection | Online Access |
| description | Polyhydroxyalkanoate (PHA) is a biodegradable and renewable thermoplastic that has potential to replace synthetic petroleum-based plastic due to their similar properties. Azotobacter vinelandii, a Gram-negative soil bacterium, is one of the microbes that can produce PHA. Many studies have been carried out to increase the production or value of PHA. In this study, a wild type strain, A. vinelandii ATCC 12837, and a deletion mutant of A. vinelandii that without or lacks the S-layer, designated as ΔAvin_16040, were used to produce PHA. The PHA accumulation was evaluated under different parameters and compared with wild-type strain. Around 3-fold higher amount of PHA was obtainable by the mutant strain compared to the wild type strain and the absence of the S-layer surrounding the cell was believed to played important role on higher PHA production. Optimisation on PHA production by the mutant strain had shown increment of 6 % and 39.5 % for cell dry weight and PHA concentration, respectively. The properties of poly(3-hydroxybutyrate), [P(3HB)] between two A. vinelandii strains were similar in terms of molecular weight, thermal and tensile properties. Besides, this bacterium is known to produce PHA containing 3-hydroxybutyrate (3HB) or mixture of 3HB and 3-hydroxyvalerate (3HV). Interestingly, in this study, 4-hydroxybutyrate (4HB) monomer was discovered to be incorporated for formation of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] by both the wild type and mutant strains when structurally-related carbon source was provided. |
| first_indexed | 2025-11-15T18:48:19Z |
| format | Thesis |
| id | usm-56170 |
| institution | Universiti Sains Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T18:48:19Z |
| publishDate | 2019 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | usm-561702022-12-31T13:02:55Z http://eprints.usm.my/56170/ Characterisation Of Polyhydroxyalkanoate Synthesis Mok, Pei Shze QH1 Natural history (General - Including nature conservation, geographical distribution) Polyhydroxyalkanoate (PHA) is a biodegradable and renewable thermoplastic that has potential to replace synthetic petroleum-based plastic due to their similar properties. Azotobacter vinelandii, a Gram-negative soil bacterium, is one of the microbes that can produce PHA. Many studies have been carried out to increase the production or value of PHA. In this study, a wild type strain, A. vinelandii ATCC 12837, and a deletion mutant of A. vinelandii that without or lacks the S-layer, designated as ΔAvin_16040, were used to produce PHA. The PHA accumulation was evaluated under different parameters and compared with wild-type strain. Around 3-fold higher amount of PHA was obtainable by the mutant strain compared to the wild type strain and the absence of the S-layer surrounding the cell was believed to played important role on higher PHA production. Optimisation on PHA production by the mutant strain had shown increment of 6 % and 39.5 % for cell dry weight and PHA concentration, respectively. The properties of poly(3-hydroxybutyrate), [P(3HB)] between two A. vinelandii strains were similar in terms of molecular weight, thermal and tensile properties. Besides, this bacterium is known to produce PHA containing 3-hydroxybutyrate (3HB) or mixture of 3HB and 3-hydroxyvalerate (3HV). Interestingly, in this study, 4-hydroxybutyrate (4HB) monomer was discovered to be incorporated for formation of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] by both the wild type and mutant strains when structurally-related carbon source was provided. 2019-11 Thesis NonPeerReviewed application/pdf en http://eprints.usm.my/56170/1/MOK%20PEI%20SHZE24.pdf Mok, Pei Shze (2019) Characterisation Of Polyhydroxyalkanoate Synthesis. PhD thesis, Universiti Sains Malaysia.. |
| spellingShingle | QH1 Natural history (General - Including nature conservation, geographical distribution) Mok, Pei Shze Characterisation Of Polyhydroxyalkanoate Synthesis |
| title | Characterisation Of Polyhydroxyalkanoate Synthesis |
| title_full | Characterisation Of Polyhydroxyalkanoate Synthesis |
| title_fullStr | Characterisation Of Polyhydroxyalkanoate Synthesis |
| title_full_unstemmed | Characterisation Of Polyhydroxyalkanoate Synthesis |
| title_short | Characterisation Of Polyhydroxyalkanoate Synthesis |
| title_sort | characterisation of polyhydroxyalkanoate synthesis |
| topic | QH1 Natural history (General - Including nature conservation, geographical distribution) |
| url | http://eprints.usm.my/56170/ http://eprints.usm.my/56170/1/MOK%20PEI%20SHZE24.pdf |