Hussain, Azieyati Hani (2025) Production Of Polyhydroxybutyrate (Phb) From Biomass Of Scenedesmus Sp. By Priestia Megaterium. Masters thesis, Universiti Sains Malaysia.
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Abstract
The high cost of carbon substrate for microbial production of polyhydroxybutyrate (PHB) currently remained as one of the obstacles in the industry, hampering the transition of conventional plastic to bioplastics. To address this situation, the biomass of Scenedesmus sp. was investigated as an alternative carbon substrate for PHB production by Priestia megaterium. First, carbohydrate content from biomass of Scenedesmus sp. was extracted using hydrothermal dilute-acid pretreatment. Among different H2SO4 concentration, temperature and treatment duration that were studied, it was found that pretreatment with 4% (v/v) H2SO4 at temperature of 105C for 30 min has released maximum total carbohydrate and total sugar of 10.66% (w/w) ± 0.05 and 8.11% (w/w) ± 0.08, respectively. Then, the growth of P. megaterium and the production of PHB in medium using sugar hydrolysate from Scenedesmus sp. (PM-MH) was evaluated for 120 h and compared to medium using glucose (PM-GLU). The maximum CDW of P. megaterium in PM-MH was 3.41 g/L, and total sugar consumed was 83.78%, which were comparable to PM-GLU (3.56 g/L, 75.7%). However, PHB yield in PM-MH was lower than PM-GLU, with value of 0.74 g/L and 1.51 g/L, respectively. Lastly, the properties of PHB produced from PM-MH (PHB-MH) was characterized and compared to the commercial PHB (PHB-C). FTIR analysis of PHB-MH confirmed the presence of functional groups unique to PHB, meanwhile DSC analysis result revealed the melting point (Tm) of PHB-MH to be 153.45°C, which is lower compared to PHB-C. All these findings demonstrate the potential use of microalgae as alternative carbon source in the production of PHB.
| Item Type: | Thesis (Masters) |
|---|---|
| Subjects: | T Technology > T Technology (General) > T1-995 Technology(General) |
| Divisions: | Pusat Pengajian Teknologi Industri (School of Industrial Technology) > Thesis |
| Depositing User: | Mr Aizat Asmawi Abdul Rahim |
| Date Deposited: | 11 Sep 2026 02:02 |
| Last Modified: | 11 Sep 2026 02:02 |
| URI: | http://eprints.usm.my/id/eprint/64926 |
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