Please use this identifier to cite or link to this item:
https://ptsldigital.ukm.my/jspui/handle/123456789/499694Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.advisor | Abdul Munir Abdul Murad, Prof. Madya Dr. | - |
| dc.contributor.author | Noor Adila Abdul Karim (P48199) | - |
| dc.date.accessioned | 2023-10-13T09:33:51Z | - |
| dc.date.available | 2023-10-13T09:33:51Z | - |
| dc.date.issued | 2015-08-16 | - |
| dc.identifier.other | ukmvital:81646 | - |
| dc.identifier.uri | https://ptsldigital.ukm.my/jspui/handle/123456789/499694 | - |
| dc.description | Pencuraian biojisim lignoselulosa oleh enzim daripada kulat selulolitik dapat ditingkatkan dengan memanipulasi sistem penghasilan selulase dan hemiselulase di peringkat molekul. Objektif kajian ini ialah untuk membangunkan mutan Trichoderma virens UKM1 yang berupaya menghasilkan selulase dan hemiselulase yang lebih baik daripada strain liar serta menentukan keupayaan enzim tersebut untuk mencurai tandan kosong kelapa sawit (TKKS) kepada gula ringkas. Didapati bahawa T. virens UKM1 berupaya menghasilkan selulase dan hemiselulase walaupun aktiviti β- glukosidase yang dihasilkan telah dikesan mengalami kesan perencatan bermula dari hari ketiga pengkulturan T. virens UKM1 di dalam medium pertumbuhan. Selain itu, penentuan keupayaan enzim daripada T. virens UKM1 terhadap hidrolisis TKKS juga ditentukan di mana kulat ini telah dikultur di dalam medium mengandungi Avicel dan enzim terhasil telah diuji terhadap pencuraian TKKS. Hasil menunjukkan selulase daripada T. virens UKM1 berupaya untuk mencurai TKKS setanding dengan enzim daripada beberapa kulat lain yang telah dilaporkan. Bagi meningkatkan keupayaan enzim daripada T. virens UKM1 untuk mencurai TKKS, mutan membawa salinan tambahan gen cbh1, eg1, bglA, abf1 dan xyn2 masing-masing mengekod selobiohidrolase, endoglukanase, β-glukosidase, α-ʟ-arabinofuranosidase dan xilanase telah dibangunkan. Kesemua gen tersebut diekspres secara berasingan dalam T. virens di bawah kawalan promoter gen gliseraldehid-3-fosfat dehidrogenase (gpd) T. virens. Enzim yang dihasilkan oleh kesemua mutan telah diuji untuk pencuraian TKKS. Hasil yang diperoleh menunjukkan enzim daripada mutan T. virens yang membawa gen abf1 dan xyn2 tambahan telah menghasilkan gula penurun yang lebih tinggi berbanding enzim daripada T. virens UKM1 jenis liar dan juga Celluclast komersil. Namun penghasilan glukosa oleh enzim daripada kedua-dua mutan tersebut tidak menunjukkan peningkatan yang signifikan berbanding dengan hasil hidrolisis daripada enzim T. virens UKM1 jenis liar dan Celluclast komersil. Selain daripada itu, bagi membantu pembinaan mutan seterusnya yang tidak bergantung kepada saringan berasaskan kerintangan antibiotik semasa proses transformasi, mutan auksotrof T. virens UKM1 telah dibangunkan. Gen pyrG mengekod orotidin-5'-monofosfat dekarboksilase yang terlibat dalam penghasilan asid amino urasil telah diganggu secara rekombinasi homologus bagi menghasilkan mutan T. virens PYRG - . Seterusnya, gen mengekod protein penindas yang mengawal atur pengekspresan gen selulase dan hemiselulase kulat, creA, telah diganggu di dalam T. virens PYRG - . Hasil analisis pengekspresan gen cbh1, egl, bgl, xyn dan abf1 di dalam T. virens CREA - menunjukkan bahawa pengekspresan kesemua gen tersebut adalah lebih tinggi berbanding pengekspresan gen tersebut di dalam T. virens UKM1 apabila dikulturkan di dalam medium minimum yang menggunakan glukosa atau selulosa sebagai sumber karbon. Analisis terhadap produk hidrolisis TKKS menggunakan enzim daripada T. virens CREA - mendapati bahawa penghasilan gula penurun dan glukosa adalah lebih tinggi berbanding enzim daripada T. virens UKM1 dan setanding dengan Celluclast komersil. Sebagai kesimpulan, kajian ini telah berjaya membangunkan mutan T. virens yang dapat menghasilkan selulase dan hemiselulase berupaya untuk menghidrolisis TKKS dengan lebih baik berbanding enzim daripada T. virens strain liar dan setanding dengan selulase komersil.,Degradation of lignocellulosic biomass using enzymes from cellulolytic fungi can be improved by the manipulation of the cellulase and hemicellulase production systems at the molecular level. The objectives of this study are to develop Trichoderma virens UKM1 mutants that are capable of producing better cellulases and hemicellulases than the wild-type and to determine the ability of the mutant enzymes to degrade oil palm empty fruit bunches (OPEFB) to simple sugars. The T. virens UKM1 was capable to produce cellulase and hemicellulase enzymes even though the β-glucosidase activity produced was detected to have inhibitory effect starting from the third day of culturing the T. virens UKM1 in the growth medium. Besides that, the ability of the T. virens UKM1 enzymes towards EFB hydrolysis was also determined where by the fungus was cultured in medium containing Avicel and the enzymes produced were tested for OPEFB degradation. The result showed that cellulases from T. virens UKM1 was able to degrade OPEFB comparable to the previously reported fungal enzymes. To enhance the ability of enzymes from T. virens UKM1 to degrade OPEFB, mutants with additional cbh1, eg1, bglA, abf1 and xyn2 that encode for cellobiohydrolase, endoglucanase, β-glucosidase, α-ʟ-arabinofuranosidase and xylanase, respectively, has been developed. All genes were expressed separately in T. virens under the regulation of T. virens glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter. Subsequently, enzymes produced by the mutants were tested for OPEFB degradation. Results showed that enzyme from T. virens mutants carrying the additional abf1 and xyn2 genes produced higher reducing sugars compared to the enzyme produced by the wild-type and the commercial Celluclast. Nevertheless, there is no significant increment in glucose production when enzymes from both mutants were used as compared to the enzymes produced by the wild-type and the commercial Celluclast. In addition, to assist in the subsequent mutant development that is not dependent on an antibiotic resistance screening during transformation, an auxotrophic T. virens mutant has been developed. The pyrG gene encodes for orotidine-5'-phosphate decarboxylase that is involved in amino acid uracil biosynthesis has been disrupted via homologous recombination to produce T. virens PYRG - mutant. Subsequently, gene encodes for a repressor protein that regulate the expression of cellulase and hemicelulase genes, creA, has been disrupted in T. virens PYRG - . Expression analysis of cbh1, egl, bgl, xyn and abf1 genes showed that their expression is higher in T. virens CREA - as compared to T. virens UKM1 when grown in minimal media containing glucose or cellulose as the carbon sources. Analysis of the hydrolytic products of OPEFB degradation using enzymes from T. virens CREA - showed an increment in reducing sugars and glucose production when compared to the enzymes produced by T. virens UKM1 and comparable to the commercial Celluclast. As a conclusion, this study has developed T. virens mutants capable of producing cellulases and hemicellulases that can hydrolyse OPEFB better than the enzymes from the wild-type T. virens and comparable to the commercial cellulase, Celluclast,Ph.D | - |
| dc.language.iso | may | - |
| dc.publisher | UKM, Bangi | - |
| dc.relation | Faculty of Science and Technology / Fakulti Sains dan Teknologi | - |
| dc.rights | UKM | - |
| dc.subject | Trichoderma | - |
| dc.subject | Pencuraian biojisim lignoselulosa | - |
| dc.subject | Kelapa sawit | - |
| dc.subject | Trichoderma. | - |
| dc.title | Pembangunan mutan Trichoderma virens untuk meningkatkan penghasilan enzim selulolitik bagi mencurai tandan kosong kelapa sawit | - |
| dc.type | Theses | - |
| dc.format.pages | 246 | - |
| dc.identifier.callno | QK625.M7 N645 2015 | - |
| dc.identifier.barcode | 001450 | - |
| Appears in Collections: | Faculty of Science and Technology / Fakulti Sains dan Teknologi | |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| ukmvital_81646+SOURCE1+SOURCE1.0.PDF Restricted Access | 4.54 MB | Adobe PDF |  View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.