Pusat Pengajian Sains Kajihayat - Tesis

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Establishment Of Callus And Cell Suspension Cultures Of Clitoria Ternatea For The Production Of Pentacyclic Triterpenoids
(2025-01)
Teoh, Siew Chin
Clitoria ternatea, or commonly known as butterfly pea, is a perennial herbaceous plant belonging to the fabaceae family. Renowned for its medicinal properties, the flowers, leaves, stems, and roots consist of a rich array of novel phytochemical compounds associated with medicinal and pharmacological properties, including pentacyclic triterpenoids particularly taraxerol and lupeol, known for their memory-enhancing properties. The current study aims to establish callus and cell suspension cultures from cotyledon explants of c. Ternatea for production of novel plant secondary metabolites associated to the mammalian neuroprotective mechanism. The in vitro cotyledon explants were subjected to callus induction and proliferation in treatments of plant growth regulators (2,4-d, naa, bap, kinetin and tdz) and sucrose concentrations (15 g/l and 30 g/l) in half-strength murashige and skoog (1962) media. The optimal proliferation media were then used for the establishment of cell suspension cultures, followed by gc-ms analysis to identify and quantify the pentacyclic triterpenoids.
Segregation Of Microsatellite Markers, Fertility AND Pathogenicity On Hylocereus undatus (Dragon Fruits) In The Interspecific Hybrid Between Fusarium fujikuroi And Fusarium proliferatum
(2023-10)
Mohd Azmurin, Emier
The main objective of this research is to further characterize the interspecific hybrids. Continuing from the previous research, several progenies have been selected and extend the information regarding those hybrids such as pathogenicity test, fertility test and molecular approach using microsatellite marker.
The Efficacy Of Biopesticides, Ipomoea Cairica (L.) Leaf Extracts And Metarhizium Anisopliae (Metsch.) On Resistant Populations Of Aedes Aegypti (L.) And Aedes Albopictus (Skuse) In Urban And Suburban Areas Of Penang Islands, Malaysia
(2024-12)
Ng, Kin Hoong
Biopesticides, derived from natural sources like plant extracts and fungi, are eco–friendly alternatives to synthetic insecticides, offering minimal environmental and human health risks while reducing resistance development. Adult bioassays revealed that urban and suburban ae. Aegypti and ae. Albopictus were resistant to four chemical insecticides (0.05% deltamethrin, 0.75% permethrin, 5% malathion, 0.25% pirimiphos–methyl), but resistance decreased with piperonyl butoxide (pbo). This study evaluated the efficacy of ipomoea cairica leaf extracts (solvent: acetone) and metarhizium anisopliae (meta–g4) in controlling insecticide–resistant aedes populations on penang island. Ipomoea cairica leaf extracts demonstrated the highest larvicidal activity against aedes aegypti urban and suburban strains, while m. Anisopliae was most effective against aedes albopictus suburban strains, with optimal mortality achieved using 500 ppm i. Cairica extract or 1×108 conidia/ml of 14–day-old m. Anisopliae. Synergistic effects were observed when 350 ppm i. Cairica was combined with 1×106 conidia/ml m. Anisopliae, achieving a robust “dual-attack” against ae. Aegypti. The compatibility of biopesticides with insecticides also enhanced efficacy against adult aedes, particularly in ae. Albopictus. Biochemical assays confirmed metabolic resistance mechanisms, with ae. Aegypti showing susceptibility but some tolerance to biopesticides, highlighting their potential in integrated resistance management.
Biosynthesis And Optimization Of P(3hb-Co-3hv-Co-4hb) Terpolymer Using Glycerine Pitch As Carbon Source
(2024-11)
Ibn, Abbas Musa
Conventional plastics have become an essential commodity that provides comfort through their applications in the packaging, medical, agricultural, and pharmaceutical industries. However, traditional plastic is recalcitrant to microbial degradation. Bioplastics like polyhydroxyalkanoates (phas) are biodegradable and biocompatible materials that have proven to be an alternative to synthetic plastics. One of the significant problems of pha biosynthesis is the cost of carbon sources, which accounts for about 40% of production costs. The use of major food-grade oils is uneconomical and unsustainable as it may limit the availability of cooking oil and trigger an increase in the price of edible oil, leading to food-feed competition. Therefore, glycerine pitch produced pha in cupriavidus malaysiensis usmaa1020 via single-stage cultivation and optimized in a 13 l bioreactor. Two other monomers were incorporated by the addition of 1,4 butanediol and 1-pentanol, resulting in the synthesis of a terpolymer consisting of 3hb, 3hv and 4hb monomers [p(3hb-co-3hv-co-4hb)]. Effects of different concentrations of glycerine pitch, 1-pentanol, 1,4 butanediol, and oleic acid were studied.
Effect Of Soil And Microbiota Composition In Black Morel Continuous And Non-Continuous Cultures
(2024-11)
Zhang, Yan
The black morel Morchella sextelata (Morchellaceae, Pezizales) is a valuable edible mushroom cultivated on a large scale, but severe yield decline occurs during continuous cropping. The effects of long-term cropping on soil properties, microbiome imbalances, and their impact on morel yield remain unclear. To help fill this knowledge gap, this study employed an indoor experiment to assess how cropping regimes affect soil properties, microbial communities, and morel production. This study assessed the impact of non-continuous cropping (NCC) and continuous cropping (CC) systems at three developing stages of M. sextelata development (bulk soil, conidial, and primordial stage) by using rDNA metabarcoding and network analysis. CC significantly reduced morel primordia yield in the third year compared to NCC, with the former showing a 99.7% reduction. The results showed that during the first year, M. sextelata mycelium overwhelmed the resident soil fungal community by reducing the alpha diversity and niche breadth of soil fungal patterns to a greater content compared to the continuous cropping regime, leading to high crop yield, but less complex soil mycobiome. To sustain continuous cropping, exogenous nutrition bags and morel mycelial spawn were consecutively added to the soil. The additional nutrient input stimulated the growth of fungal saprotrophic decomposers.

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