Pusat Pengajian Sains Kajihayat - Tesis

Browse

Now showing 1 - 20 of 69

Anti-Apoptotic Proteins Mcl-1 And Bcl-Xl Are Crucial For Nasopharyngeal Carcinoma Cell Survival
(2022-11)
Abdul Rahman, Siti Fairus
Malaysia has one of the highest national incidences of Nasopharyngeal carcinoma (NPC) in South-East Asia. Treating patients with metastatic NPC is often a challenge as patients develop resistance to systemic anti-cancer therapies such as chemotherapy and retreating local recurrence with radiotherapy have many limitations. Hence, improved treatment strategies are needed for better patient outcome. Upregulation of the anti-apoptotic protein BCL-2 is one of the strategies that cancer cells adopt to evade cell death. Hence, these proteins have become attractive therapeutic targets. Given that different cell population rely on different anti-apoptotic proteins for survival, it is crucial to determine which proteins are important for NPC cell survival. Previous study reported that co-inhibition of BCL-2 and BCL-XL did not induce cell killing in NPC cells, which indicate that either MCL-1 or BFL-1 may play an important role in the survival the NPC cells. Given that the roles of MCL-1 and BFL-1 for NPC cell survival are under-explored, this study will primarily focus on delineating the functional roles of these two molecules for cell survival using gene editing and pharmacological approaches.
Antibacterial Activity Of Prodigiosin Extract Against Opportunistic Shrimp Gut Bacteria Isolated From Litopenaeus Vannamei
(2022-03)
Mohamad Suhaimi, Nurul Syakirah
Disease in cultivated shrimp nowadays has seen as the critical problem to the aquaculture world production. The excessive and abusive used of antibiotic to treat bacterial infection, however, have driven the development of antimicrobial resistant. These issues have raised many problems to the shrimp aquaculture industry and nearby environment. Therefore, searching of new treatment method is important especially from natural substances against opportunistic and pathogenic bacteria. The objective of this research study was to assess the antibacterial activity of prodigiosin extract of marine bacterium Serratia marcescens IBRL USM84 against opportunistic bacteria isolated from the infected shrimp gut of L. vannamei. Extracellular crude extract was selected as it showed a better inhibitory effect with faster killing rate on tested bacteria compared to intracellular crude extract.
Antimycobacterial Potential Of Secondary Metabolites Of Actinobacteria From A Tropical Mangrove In Northern Peninsular Malaysia
(2023-07)
Adanan, Norshamiera
Actinobacteria play a crucial role in discovery of new antibiotics for diseases with known antimicrobial resistance, such as multidrug-resistant tuberculosis (TB) caused by Mycobacterium tuberculosis (MTB), which is becoming a major impediment to TB control worldwide. In this study, novel actinobacterial secondary metabolites with antimicrobial potential against MTB surrogate organisms were isolated from tropical mangroves in the northern region of Peninsular Malaysia. The objectives of this study were to 1) isolate and screen for antimycobacterial-producing actinobacteria in sediment and water samples from mangrove environments, 2) conduct crude extract evaluation using tetrazolium microplate assay (TEMA), checkerboard assay and time-kill assay to determine minimum inhibition and bactericidal concentration (MIC, MBC) and fractional inhibition concentration index (FICI), and 3) identify compounds through gas chromatography mass spectrometry (GCMS) analysis. A total of 54 mangrove actinobacterial isolates were isolated from three mangrove environments in Balik Pulau, Pulau Pinang, and Merbok, Kedah from water and sediment samples of four sites: crab holes, rhizosphere area, undisturbed area, and disturbed area.
Behavioural Ecology And Conservation Management Of Dusky Langurs (Trachypithecus Obscurus) In Penang, Malaysia
(2022-10)
Yap Jo Leen
In this study, the activity budget, habitat use, and diet of four habituated study groups in different habitat types in Penang were assessed to better understand how langurs behave in anthropogenic environments. This study was conducted between January 2016 and December 2019 using behavioural sampling techniques such as scan, focal sampling, vegetation plotting, home range assessment, and camera trapping.
Behavioural, Morphological And Chemical Strategies In Social Integrations Of Myrmecophilidae Crickets To Host Ants, Paratrechina Longicornis And Anoplolepis Gracilipes
(2021-11)
Mark Ooi Chuan Sen
This thesis focusses on the integration strategies of ant crickets from the family Myrmecophilidae in colonies of invasive ants, Paratrechina longicornis (Latreille, 1802) and Anoplolepis gracilipes (Smith, 1857) (Hymenoptera: Formicidae) through behavioural, morphological, and chemical integration strategies.
Biodegradation Of Waste Cooking Oil And Waste Engine Oil By Locally Isolated Microfungus, Aspergillus Spp. USM-Ar1
(2022-07)
Jasme, Nurshafiqah
Large amounts of waste cooking oil and waste engine oil from residential areas and automotive industry, respectively, can impose adverse impact if not disposed off properly. Fungi have a higher tolerance to hydrocarbon toxicity due to their physiology and adaptation to the environment, subsequently equipped with the mechanism for oil utilisation. Therefore, bioremediation using fungi can be employed for waste oil reduction in the environment. In the present study, a filamentous fungus was isolated from used charcoal coated with animal fats, identified morphologically as Aspergillus sp. USM-AR1. The highest oil removal and fungal biomass of waste cooking oil in shake flasks obtained were 81.93 ± 14.22% and 81.67 ± 11.08 g/L, respectively at 144 h in a medium containing 9.83% (v/v) waste cooking oil, 1 g/L ammonium nitrate, 16.32% (v/v) NaCl, 10% (v/v) inoculum concentration and with the initial pH of 8.32 after optimisation studies.
Biomass Production Of Aureispira Sp. Ccb-qb1 And Its Application As A Novel Bioflocculant
(2022-05)
Rahman, Nur Hasyimah Abdul
Bioflocculants are important to remove pollutants, especially organic particles and heavy metals from wastewater. Previous study showed that Aureispira sp. CCB-QB1 demonstrated cell aggregation when calcium ions are available. This suggested that these bacterial cells are capable to adsorb the waste materials and have a great chance to be a novel bioflocculant. Therefore, in this research, the methods for cultivation of Aureispira sp. CCB-QB1 inside a bioreactor was studied. Then, the biosorption activity of the dead cells toward heavy metals (Fe3+ and Cu2+) was tested. The QB1 dead cells were prepared by treating the living cells using 0.5 % of formaldehyde. The dead cells were discovered to show robust flocculating activity toward kaolin (initial concentration 0.2 %) in the presence of 7 mM CaCl2. For cultivation inside flasks, 5 ml of the dead cell suspension showed overall of 96 % of flocculating activity after shaken using both 150 and 200 rpm agitation speeds. Besides, both tryptone and peptone were found to highly supported the growth of QB1 cells. The presence of peptone in the cell culture also helps in the aggregation of the QB1 cells. For cultivation inside a bioreactor, QB1 culture conditions were optimized using Response Surface Methodology (RSM). The optimized conditions were 3.39 % of sea salt concentration, 0.9 % of peptone concentration, and 29 h of incubation period. Additionally
Biosynthesis And Characterization Of Poly(3-Hydroxybutyrate-Co-3- Hydroxyvalerate) From Cupriavidus Malaysiensis Usmaa1020 Using Glycerin Pitch As Main Carbon Source
(2022-11)
Rozina, Rozina
Plastics are used in almost every part of modern life, from making aeroplanes, cars, and buildings to making clothes, shoes, packaging for food and drinks, and medical devices. As a result, plastic waste is gathered globally, worsening the effects on the ecosystem. Synthetic plastics/conventional plastics takes many years to disintegrate in nature, and incineration produces toxic substances and raises CO2 levels in the atmosphere, causing issues like global warming. As a result, alternatives to petrol-based polymers are being sought. Polyhydroxyalkanoates (PHAs) have been proposed as a feasible substitute for petrochemical-based polymers because of their biodegradable nature. In the present study, Cupriavidus malaysiensis USMAA1020, a Gram-negative bacterium was able to produce biodegradable polymer P(3HB-co- 3HV) by utilizing glycerin pitch which is a by-product of the biodiesel synthesis obtained during the transesterification as low-cost feedstock. The aim of the research was to screen various concentrations of glycerin pitch (5 g/L, 10 g/L, 15 g/L, 20 g/L, 25 g/L), 1-pentanol (0.03 wt% C, 0.06 wt% C, 0.09 wt% C, 0.12 wt% C), ammonium sulfate (0.8 g/L, 1.1 g/L, 1.4 g/L, 1.7 g/L, 2.0 g/L), and different precursors nonaoic acid, valeric acid, propionic acid, with respect to 1-pentanol at concentration of 0.06 wt%C. To enhance the production of PHA, oleic acid concentrations was used as a secondary carbon source.
Characterisation Of Fungi Associated With Diseased Cocoa (Theobroma Cacao) In West Coast Of Peninsular Malaysia
(2023-07)
Abd Rahim, Huda Shakirah
Cocoa (Theobroma cacao) is an evergreen tree belonging to the Malvaceae family. The cacao plant has contributed significantly to the country's economy and has also become a source of income for smallholder farmers. However, fungal diseases are one of the major problems in cocoa plantations, where the spread of uncontrollable infections can lead to significant yield losses. The objective of this study was to identify and characterise the fungal isolates associated with diseased T. cacao in Malaysia through morphological, molecular, and pathogenicity analyses. Diseased samples of leaves, stems, and pods of T. cacao were collected from different plantations in Malaysia. Morphological and molecular analyses were carried out to identify the fungal isolates. Phylogenetic analysis was carried out to accurately identify and characterise the fungal isolates using various genes such as internal transcribed spacer (ITS), translational elongation factor 1-alpha (tef1-α), β-tubulin (tub2), glyceraldehyde-3-phosphate dehydrogenase (gapdh), and RNA polymerase subunit II (rpb2). To assess the pathogenic capabilities of the fungal isolates, pathogenicity tests were carried out on healthy leaves, stems, and pods of T. cacao using mycelial plugs with wound treatment. A total of 116 fungal isolates were isolated from diseased leaves, stems, and pods of T.
Characterisation, Pathogenicity, And Mycotoxin Analysis Of Fungal Endophytes Of Corn (Zea Mays L.) In Peninsular Malaysia
(2022-06)
Paul, Terna Tersoo
Endophytes are microbes that infect internal tissues of host plants for all or part of their life cycles, without causing any visible symptoms of disease. Depending on a number of factors such as the developmental stage of both host plant and fungus, environmental factors, and host defence responses, fungal endophytes indwelling tissues of host plants may become latent plant pathogens. In Peninsular Malaysia, works on endophytic fungi carried out so far have focused mainly on their ecological and functional roles in enhancing plant growth and other survival attributes, while much remains unknown regarding the disease initiation, and mycotoxin-producing potentials of fungal endophytes especially of corn and other cereal crops. Thus, the present study was carried out to identify, evaluate the pathogenicity, and investigate the mycotoxin-producing potentials of endophytic fungi resident in corn plants grown on different fields in Peninsular Malaysia. Using a combination of morphological and molecular techniques, endophytic fungi recovered from tissues of corn plants were identified in seven genera, namely Fusarium, Penicillium, Aspergillus, Aureobasidium, Cladosporium, Epicoccum, and Curvularia. Based on BLAST search and phylogenetic analysis of combined β-tubulin and TEF-1α sequences, endophytic Fusarium species isolated from corn plants were molecularly identified as F. pseudocircinatum, F. verticillioides, F. andiyazi, F. sacchari, F. mangiferae, F. fujikuroi, F. proliferatum, and F. incarnatum. Endophytic Penicillium species were identified as P. oxalicum, P. polonicum, and P. citrinum, based on ITS region and β- tubulin gene. Combined sequences of ITS region, β-tubulin, and Calmodulin genes were used to identify endophytic Aspergillus species as A. flavus, and A. tubingensis, ITS region and β-tubulin gene for the identification of A. pullulans, ITS region and ACT gene for identification of C. tenuissimum, while combined ITS region and LSU gene were used for identification of E. sorghinum and C. lunata.
Characterization Of CTP Synthase In Zebrafish (Danio Rerio)
(2019-08)
Abdul Wahab, Nurul Wahidah
CTPS is an enzyme that catalyzes the synthesis of cytidine triphosphate (CTP), one of the four basic nucleotide triphosphates that make up DNA and RNA. CTPS dysregulation has been implicated in many different diseases and cancers. It was also shown previously that CTPS can form filamentous structures called cytoophidia. This structure was found on yeast, fruit flies and human. Nevertheless the mechanism behind cytoophidia formation is still vague. To date, there are no in depth studies yet on characterizing CTPS on Danio rerio (zebrafish) and as there are two CTPS genes in zebrafish i.e ctpsla and ctpslb utilizing zebrafish as model organism can further help to understand the CTPS and its cytoophidia. In this studies, the antibody staining results shows that in developing embryos, CTPS is concentrated on the pronephric duct area and the notochord at the end tail area.
Characterization Of Pyricularia Oryzae Causing Rice Blast From Rice Granary In Peninsular Malaysia
(2021-12)
Siti Norsuha Binti Misman
The objectives of this study were to characterize P. oryzae isolates based on their morphological characteristics, identify P. oryzae pathotypes based on disease reaction to Malaysian Differential Varieties (MDVs), determine the genetic diversity of P. oryzae isolates based on molecular characterization and identify the virulence pattern of identified selected P. oryzae isolates (pathotypes) against specific gene for resistance harbored in the IRRI bred blast monogenic lines (IRBLs).
Control Of House Fly, Musca Domestica L. (Diptera: Muscidae) Population In Poultry Farms
(2017-08)
Ong, Song Quan
House flies is the most important pest in poultry units. This study aimed to predict the population changes of house fly population and propose a control threshold, to evaluate the effectiveness of selected insecticide by comparing their LC50 between susceptible and wild strain, to determine the half-life and degradation rates of insecticides by spiking these insecticides into poultry manure, and to study the interaction between the Metarhizium. anisopliae (MET.) and the insecticides in order to control the house fly population. Population changes of house fly was first defined the knee points of a known population growth curve as a control threshold by comparing the rm of five densities of house flies in a simulated condition. Later, to understand the interactions between the larval and adult populations, the correlation between larval and adult capacity rate (rc) was studied.
Cyanobacterial Diversity In Selected Tropical And Polar Environments
(2019-04)
Abdul Rahman, Nur Fadzliana
Cyanobacteria are the most ancient and widespread group of photosynthetic prokaryotes and had a major role in the evolution of the plant kingdom and Earth’s atmosphere. They are primary producers in a wide variety of habitats and are able to thrive in harsh environments. This study explored the cyanobacterial communities in sediment and soil samples collected from selected areas from Antarctic (Browning Peninsula, Dee Island, Greenwich Island and Reeve Hill), Arctic (Kvartsitsletta and Polish Polar Station) and Tropical (Air Terjun River, Air Itam River, Dondang River, Jelutong River and Pinang River) regions, by identifying taxa via 16S rRNA gene amplicon sequence data. 16S rRNA gene amplicons generated from 11 samples were sequenced using illumina Miseq, with the targeted V3 and V4 regions yielding approximately 1 million reads per sample. East Antarctica (Browning Peninsula and Reeve Hill) recorded nine genera of cyanobacteria and west Antarctica (Dee Island and Greenwich Island) recorded seven genera. The two Arctic sampling sites recorded the lowest number of genera, five.
Development Of Alginate-Gelatin Hydrogel Beads: A Baiting Tool For Dengue Vectors As Mosquito Control Strategy
(2023-03)
Noor Muokhni Binti Ayub
We found that the mosquitoes achieved total mortality after consumption, and the number of female attempts to blood-feed also reduced after 6 hour of exposure. We conclude that the AGHBs are applicable as a baiting tool to carry the liquid bait in achieving mosquito mortality and at the same time reduced in blood-feeding.
Development Of An Efficient Protocol For The Production Of Phalaenopsis Hybrid Orchid Plantlets
(2022-09)
Rajasegar, Arulvilee
As a monopodial plant, Phalaenopsis is traditionally propagated by off-shoot cutting or division. However, this resulted in a low multiplication rate and hinders the growth of the mother plant and therefore inefficient for large-scale production. Micropropagation has provided a valuable alternative method for the large-scale production of identical orchid plantlets within a short period. The study aimed to improve the proliferation of protocorm-like bodies (PLBs) of Phalaenopsis Fuller’s Light × Phalaenopsis Purple Heart through the micropropagation method. The thin cell layer culture (TCL) approach generated a 2.16 times higher neo-PLB formation rate than the conventional half-PLB explants. The medium composition of full MS medium supplemented with 3% sucrose, 2% banana extract, and 15% coconutwater significantly produced the highest PLB fresh weight (2.499 g) after 4 weeks of culture. The Phalaenopsis PLBs further developed into shoot and root using 1.0 mg/L BAP and NAA mg/L. The incorporation of 1.5 mg/L of glutamine resulted shoot formation with 70% while 1.5 mg/L of arginine increased root formation by 87%, wherein the cultures were differentiated into complete plantlets.
Development Of Broodstock Maturation Feed With Supplementation Of Arachidonic Acid (Ara, 20:4n-6) And Docosahexaenoic Acid (Dha, 22:6n-3) For Female Giant Freshwater Prawn, Macrobrachium Rosenbergii
(2023-08)
Ibrahim, Saadiah
The giant freshwater prawn (GFP), Macrobrachium rosenbergii (de Man, 1879), is one of the important commodities in Malaysia's aquaculture industry. The main challenge in Macrobrachium farming is the supply of high-quality seeds, which has become an increasingly critical issue. To address this problem, a study was conducted to investigate the effects of feeding maturation diets containing arachidonic acid (ARA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3) at optimal levels on the maturation and breeding performance of female M. rosenbergii. The research aimed to evaluate the impact of maturation diets enriched with ARA and DHA on the maturation of female GFP, including assessments of gonad development, egg quality, larval quantity, and oocyte size. The analysis also included the examination of fatty acid content in the shrimp's body. The study employed different formulations of maturation diets with varying ARA and DHA levels, comparing them with a control diet. Parameters studied in the female GFP given the experimental diets included reproductive effort, egg quality, larval yield, gonad and hepatopancreas histology, and fatty acid content in the study samples. Three feeding trial experiments were conducted to develop the maturation diets for female M. rosenbergii. The first experiment examined the effects of different diet forms and moisture content on the reproductive performance of female M. rosenbergii. The second experiment aimed to determine the optimal dietary ARA level for enhanced reproductive performance of female GFP
Development Of V Cryo-Plate Method Of Ludisia Discolor (Ker Gawl.) A. Rich For Long-Term Germplasm Conservation
(2022-03)
Rajan, Kirutika Selva
Ludisia discolor is a jewel orchid that is well known for the striking leaves than its flowers. Other than being used as an ornamental plant, this orchid is also being exploited for its medicinal properties. Hence, L. discolor facing possible depletion in its natural habitat lately due to over-harvesting. Recently, the latest cryopreservation methods such as V cryo-plate is needed for long-term germplasm conservation. This study aims to develop a V cryo-plate cryopreservation method for L. discolor axillary buds to perform microscopy analysis of cryopreserved explants, determine the water content changes, and genetic stability between control and treated explants. Six (6) parameters have been optimized in this V cryo-plate method which are preculture concentration and duration, types of loading solution, duration on PVS2, thawing temperature, and thawing duration.
Displaying Of Green Fluorescent Protein On A Recombinant Bacteriophage Infecting Escherichia Coll Atcc 11303
(2017-03)
Ong, Jia Wei
Phage display technology allows the presentation of foreign peptides on the surface of a bacteriophage. Phage display technology is used to acquire the function of the displayed peptides which was not present on wild type bacteriophage. Using phage display technology, a recombinant phage would be constructed as a model for future manipulation. The technology was applied to display a green fluorescence protein (GFP) on tail protein of Escherichia Phage YD-2008.S to create GFP labelled recombinant bacteriophage.
Diversity Of Bacteria In Breeding Water And Midgut Of Aedes Albopictus, And Determination Of Its Paratransgenic Candidates And Ovipositional Attractant
(2023-06)
Mohd Fadzlah, Fadhlina Hazwani
Researchers have started to focus on vector management and implementation of biological control to replace the hazardous effect of excessive insecticide usage. This study was conducted to provide fundamental knowledge of bacteria diversity in breeding water and midgut of Aedes albopictus. The identification of these bacteria is important for its roles as paratransgenesis and oviposition attractant. The culture-dependent and culture-independent methods were used for the comparative assessment of bacteria from artificial containers with the presence and absence of larvae. Interestingly, the culture-dependant method showed a higher bacterial diversity in breeding water with the presence of larvae but higher operational taxonomic units (OTUs) in the absence of larvae by culture-independent method. These results highlighted the importance of a type of bacterium that is responsible for the attraction or deterrent effects towards mosquitoes. Higher microbiota diversity present in an adult mosquito’s midgut compared to larval stage concluded that both environmental and vertical inheritance are the microbiota sources in the midgut. The consistent presence of Bacillus cereus and Proteus mirabilis in breeding water and both stages of Ae. albopictus mosquito’s midgut served as potential early candidates for the paratransgenesis. The paratransgenic candidates tested for B. cereus and P. mirabilis showed that the B. cereus was beneficial and more suitable as paratransgenic candidate.

Browse

Browsing Pusat Pengajian Sains Kajihayat - Tesis by Title

Results Per Page

Sort Options