Pusat Pengajian Sains Kajihayat - Tesis

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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.
Antibacterial And Antibiofilm Activities Of Ethyl Acetate Extract Of Nigrospora Sphaerica Cl-Op30 Isolated From Swietenia Macrophylla Leaf
(2019-07)
Ahmad Mokhtar, Nur A’fina
This research was aimed to study antibacterial and antibiofilm activities of an endophytic fungus Nigrospora sphaerica CL-OP30 isolated from Swietenia macrophylla plant. Quantitative measurement of antibacterial activity revealed that this endophyte produced the highest antibacterial activity at day 12 of cultivation.
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.
Assessment Of Bornean Orangutans Based On Nest Structure Using Unmanned Aerial Vehicle (UAV), Nesting Site Preferences And Parasitic Prevalence
(2019-08)
Kamaruszaman, Salniza Akmar
In the current developing era, the importance of orangutans is being forgotten. The function of rehabilitation centres in conserving the animals need to be monitored and supported. Orangutans nesting skill and parasitic prevalence illustrate an important role in a rehabilitation centre. Hence, this study aims to determine the variation of nest structure quantitatively, the nesting site preference and the prevalence of gastrointestinal parasite in orangutans.
Bacterial Population Of Pteris Vittata With Potentials For Bioremediation Of Arsenic Rich Soils And Plant Growth Promotion
(2024-03)
Salisu, Muazu Aminu
In soil environments, certain bacteria can withstand arsenic-induced stress and play vital roles in agriculture as plant growth-promoting rhizobacteria (PGPR). The bacteria enhance plant growth and contribute to the bioremediation of toxic arsenic in soils. This process also involves a selected group of plants known as hyperaccumulators, such as Pteris vittata, which enhance the efficiency of arsenic removal from the soil. Various methods are being used to cleanse the environment from the adverse effects of arsenic pollutant, but most of these methods are not cost-effective and have very poor performance. Bioremediation is used as a practical approach to address pollution caused by arsenic. This study aims to determine the bacterial population of P. vittata with the potential for bioremediation of arsenic-rich soils and plant growth promotion. The 16S amplicon metagenomics analysis was employed to determine the composition, functions, and bacterial diversity of soils from arsenic-rich and natural mineral sites. Conventional methods were employed to isolate, screen, and identify bacteria potentials for plant growth promotion, arsenic and other metals tolerance, detoxification, and bioremediation abilities. The selected isolates were evaluated for their efficiency in mitigating the toxic effects of arsenic, plant growth promotion and enhancement of the hyperaccumulation ability of P. vittata under different arsenic stress condition.
Basal Stem Rot Of Oil Palm Disease Development Planted On Mineral And Peat Soils And Pathogenicity Of Ganoderma
(2024-06)
Virdiana, Ike
Oil palm (elaeis guineensis jacq.) has high economic value and contributes to the economy of many producing countries, especially indonesia and malaysia as the leading producers in the world. Oil palm is infected by ganoderma fungus causing basal stem rot (bsr) disease, a serious disease affecting oil palm productivity in indonesia and malaysia. In indonesia, a high incidence of bsr has been reported in oil palm planted in mineral and peat soils particularly in second generation plantings. The objectives of the present study were to identify ganoderma isolates associated with bsr in both mineral and peat soils, to conduct pathogenicity tests of ganoderma isolates from mineral and peat soils and to observe and monitor bsr disease development in infected areas in peat and mineral soil plantings. Sixteen ganoderma basidiocarps were successfully collected and isolated from infected oil palm in both simalungun (mineral soil) and south labuhan batu (peat soil) plantations in north sumatra, indonesia. The morphological characteristics of basidiocarps fall within the description for ganoderma boninense. In order to accurately identify the fungal isolates, dna sequencing of internal transcribed spacer (its) region was applied and 600 bp band were produced. Based on blast search, the isolates showed 99 – 100% similarity with the g. Boninense sequences deposited in the genbank. Phylogenetic analysis indicated the isolates from mineral soil and peat soil were grouped together along with g. Boninense reference which confirmed the isolates from both soil types as g. Boninense.
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.
Biochemical Characterization And Analysis Of Moringa Oleifera Seeds On Mcf7 Cells
(2019-07)
Ismail Abiola, Adebayo
In this study, the antioxidant activity of the plant seed and its antiproliferative effect against Michigan Cancer Foundation-7 (MCF7) breast cancer cells were investigated, and the underlying mechanisms of actions involved were unravelled using molecular biological methods such as 2-dimensional gel electrophoresis (2- DE), western blotting and reverse transcription polymerase chain reaction (RT-PCR). l,l-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6- sulphonic acid (ABTS) tests showed that all the extracts and fractions from the seeds have antioxidant capacities.
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 And Pathogenicity Of Fungi Causing Sooty Blotch And Flyspeck (Sbfs) Disease Of Mango (Mangifera Indica L.) In Peninsular Malaysia
(2024-09)
Tham, Khai Xin
The sooty blotch and flyspeck (SBFS) disease complex, caused by multiple fungal species, leads to black smudges and clusters of black spots on various fruits, including mango, impacting their marketability as fresh fruit. Although not previously reported in Malaysia, field visits in 2018 found similar SBFS disease symptoms on mango in various orchards in Perak. Therefore, this research aimed to: 1. Isolate and identify SBFS fungi on mango collected from Perak, Pahang, and Perlis based on morphological and molecular approaches; 2. Assess the phylogenetic relationship among the SBFS fungal isolates; 3. Determine the pathogenicity of the SBFS fungi isolated from mango. A total of 87 mango fruit showing SBFS disease symptoms were collected, and the number of SBFS colonies on each mango (CPM) and the percentage area of SBFS infection were determined. Subsequently, 2106 mango peel samples were obtained and subjected to isolation. Morphological characterization resulted in the identification of 33 pure cultures belonging to SBFS fungal genera, such as Zasmidum, Peltaster, Exophiala, Pseudocercospora, and Ochroconis. The DNA sequencing of the internal transcribed spacer (ITS) and large subunit (LSU) confirmed 18 representative isolates as distinct species, including Z. citrigriseum, Z. aporosae, Peltaster-like species, ‘Pseudopeltaster’, E. bergeri, E. spinifera, Pseudocercospora species, and O. cordanae. Phylogenetic analyses using maximum parsimony (MP) and maximum likelihood (ML) approaches indicated that the SBFS fungal complex on mango was related to both known SBFS members globally and non-SBFS taxa.
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 Aerophytic Oxyphototrophs Isolated From Gua Tempurung, Malaysia: Polyphasic And Biochemical Approaches
(2024-03)
Abdullahi, Zulaihat Hamza
Caves are among the extreme oligotrophic environments with limited nutrients and low light intensity, but some aerophytic microalgae find this environment suitable for their growth and survival. Gua Tempurung is the largest limestone caves in Malaysia, but unfortunately no study was conducted on its algal diversity, taxonomic information, adaptation, physiological, and biochemical composition. This study aimed to assess the characteristics and adaptation of aerophytic oxyphototrophs isolated from Gua Tempurung.
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).
Compatibility And Biodegradability Of Biopolyester-Based Blends With Poly(3-Hydroxybutyrate-Co-3-Hydroxyhexanoate) (Phbh) As A Blend Matrix
(2024-07)
Jeepery, Iffa Farahin
Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (phbh) has been evaluated to have excellent degradability in marine environment. However, its performance for application is still limited. A series of properties enhancement is deemed necessary to improve the potential of phbh being both a high-performance material and readily biodegradable. In this study, phbh containing 5 and 17 mol% 3-hydroxyhexanoate (3hh) were blended with atactic poly(3-hydroxybutyrate) (phb), polycaprolactone (pcl), and polybutylene succinate (pbs) at different ratios by the solvent-casting method. Phbh-5%/atactic phb and phbh-17%/atactic phb showed a single glass-transition temperature (tg), indicating miscibility in the amorphous state. Immiscibility was observed in the phbh-5%/pcl and phbh-17%/pcl blends based on the non-transitioning tg of the phbh component, presence of two distinct tg values for some of the blend films, and individual crystallization manner. The thermal properties and spherulitic morphologies of the phbh-5%/pbs blend films suggested partial miscibility. The enzymatic degradability of the three types of blends by ralstonia pickettii t1 phb depolymerase and burkholderia cepacia lipase was investigated. Depending on the enzyme–substrate specificity, miscibility, and phase structure of the blend, the enzymatic erosion rate was different among the three types of blends.

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