Volume 10, Issue No 3, September 2023

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Issues in Volume 10
I No 1 II No 2 II No 2-2 II No 3 (this issue) II No 4 I

Cover Page and Table of Contents

In silico analysis and structure modelling of heat shock protein HSP70 from Glaciozyma antarctica PI12 as a model system to understand adaptation strategies of Antarctic organisms amid adverse climates
Wan Nur Shuhaida Wan Mahadi; Clemente Michael Wong Vui Ling; Hyun Park; Nur Athirah Yusof. 2023. Transactions on Science and Technology, 10(3), 122 - 149.
Abstract The 70-kDa heat-shock proteins (HSP70) are integral components of the cell’s folding catalysts. Glaciozyma antarctica PI12 is an obligate psychrophilic yeast that possesses six HSP70 genes in its genome. The functions of these HSP70s in G. antarctica in terms of similarities and differences are yet to be discovered. The purpose of this study is to determine the structure and function of HSP70 from G. antarctica, which will lead to understanding this organism's adaptation strategies through structural and functional annotation. In this study, we utilize the HSP70 genes derived from genome data of Glaciozyma antarctica PI12 isolated from the Casey Research Station to characterize and compare structural characteristics which may contribute to their adaptation strategies during global warming. Computational tools such as Expasy’s ProtParam, MEGA 11, SWISS-MODEL, AlphaFold2, and SAVES were used to analyze all the genes via physicochemical analysis, phylogenetic study, homology modelling and structure validation, and superimposition of models. Results showed that reliable 3D models of HSP70 were successfully generated via the homology modelling approach using SWISS-MODEL and AlphaFold2 programs. The proposed model was evaluated as reliable with high confidence based on the structural stereochemical property, verification of protein patterns of non-bonded atomic interactions, compatibility of a 3D model with its amino acid sequence and determination of the protein's native fold. Among the new findings are the molecular signatures such as ionic, aromatic-aromatic, aromatic-sulphur and cation-pi interactions that are lesser in the buried residues when compared to their homologs. These interactions are important for maintaining structure stability, flexibility and packing in proteins. This may reflect the yeast response and adaptation strategies during the adverse climate. By studying the structural adaptations of HSP70 proteins in psychrophilic yeast, researchers can gain insights into how these proteins maintain their functionality in changing temperature conditions. This knowledge can inform the development of strategies to mitigate the impact of global warming on cold-adapted organisms and potentially guide the design of novel enzymes with improved thermal stability for biotechnological applications. In conclusion, this comprehensive study provides an in-depth understanding of the structural adaptation and evolution of HSP70 about their thermal resistance to global warming.
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Herbs recognition based on chemical properties using machine learning algorithm
Nur Fadzilah Mohamad Radzi; Azura Che Soh; Asnor Juraiza Ishak; Mohd Khair Hassan. 2023. Transactions on Science and Technology, 10(3), 150 - 155.
Abstract For decades, the headspace Gas Chromatography Mass Spectrometry (GCMS) technique has been employed to analyse Volatile Organic Compounds (VOCs), extracting chromatographic signals and identifying chemical components. In practical scenarios, identifying major chemical compounds has been a useful approach for herb experts to recognize and differentiate species. However, this process has been manual and lacked an automated herb recognition system that incorporates GCMS technology. To address this gap, a GCMS herb recognition system has been proposed, integrating the GCMS system with a pattern recognition approach. Innovatively, a new feature extraction method using the Weighted Histogram Analysis Method (WHAM) has been introduced. This method employs a reweighting technique that utilizes the peak area and peak height of VOCs to generate a unique pattern for each herb species. A comparison of classification performance between systems with WHAM shows that the Support Vector Machine (SVM) method achieves a higher percentage of accuracy, ranging from 92.32% to 95.67%, compared to without WHAM, which achieves an accuracy ranging from 57.43% to 62.11%. This method has demonstrated promising results in identifying herb species, and the classification method based on machine learning algorithms has proven successful in recognizing and distinguishing herb species.
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Epoxy-Graphene composite reinforced with bamboo biochar powder: Effect on mechanical properties
Mazlan Mohamed; Nor Rohimah Abdullah; Jidon Janaun; Hasyiya Karimah Adli; Mohamad Faiz Mohd Amin; Arman Shah; Muhammad Iqbal Ahmad. 2023. Transactions on Science and Technology, 10(3), 156 - 163.
Abstract Epoxy-graphene composites have been widely used in many applications due to their exceptional properties, such as excellent mechanical strength, thermal ability, electrical conductivity, and chemical resistivity. Bamboo is a natural resource that could be regarded as a high-performance material that involves low production costs. It is grown easily and is quicker to harvest than other natural resources. Bamboo biochar (BB) can be produced using the pyrolysis method. Studies on the effects of using biochar as filler in epoxy composites have proven that this approach can increase the mechanical strength of the material. The role of BB has been studied by researchers, but only as fertilizer. Little research has been undertaken on the mechanical properties of BB, especially when used as filler in a composite material. This research aimed to determine the effects of adding BB as filler in epoxy-graphene composites. Using pure epoxy and epoxy-graphene composites (EG) for reference, the mechanical properties of an epoxy-bamboo biochar composite (EB) and an epoxy-graphene-bamboo biochar composite (EGB) were investigated. Thus, the role of BB in enhancing the mechanical properties through its matrix was properly observed and studied. The composites were fabricated using the solution blending method, whereby all the mixtures were mixed homogeneously before being degassed in a vacuum chamber. Curing took place in an oven at 70 °C for 24 hours, and post-curing occurred at room temperature for an hour before demolding. Tensile and three-point bending tests were conducted to analyze the tensile and flexural properties of the composites. The tensile strength of EB showed a 56.216% increment compared to that of pure epoxy, while BB filler increased the tensile strength of EGB by 12.350% compared to that of EG. The flexural strength of EB increased by 0.258% compared to that of pure epoxy, while EGB had 6.535% higher flexural strength compared to EG. Scanning electron microscopy (SEM) was conducted on the sample EB, EG, and EGB at magnifications of 100x, 500x, and 1000x. Graphene agglomeration could be observed on the sample containing graphene. The dispersion of graphene and BB could be observed clearly. The study indicates that bamboo biochar altered the mechanical properties of the epoxy-graphene composite by increasing the tensile strength and stiffness, although it reduced the flexibility of the material.
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Effect of ball milling time on structural properties and colour analysis of calamansi (Citrus microcarpa) peel powder
Umra Sumina Mohamed Telidi; Nora Salina Md Salim. 2023. Transactions on Science and Technology, 10(3), 164 - 169.
Abstract Calamansi (Citrus microcarpa) is a common lime widely used in food flavouring, herbal medicines and juice processing. The peel, which is the primary by-products of the juice processing industry has the potential to be utilized in powder form. This resulting powder offers versatility for use in both food and non-food applications. Therefore, drying and milling is essential unit operations for food powder production. In this study, the effect of ball milling time (30 to 120 minutes) on the morphology, structure and colour of freeze dried calamansi peel powder was investigated. The results demonstrate that extending the ball milling time from 30 to 120 minutes transforms large fragments into smaller particles, while maintaining structural integrity and enhancing the green colour of freeze-dried calamansi peel powder. These findings indicate the effective change in particle size and the resulting changes in the material's physical properties, allowing for tailored utilisation and application across a wide range of applications.
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The isolation of human intestinal parasites from American cockroach: A preliminary study
Nur Athirah Hashim; Azlinda Abu Bakar. 2023. Transactions on Science and Technology, 10(3), 170 - 174.
Abstract Human intestinal parasitic infection results from the invasion of the human gastrointestinal system by intestinal helminths and protozoan parasites, often facilitated by factors such as mechanical transmission by household insect pests, notably American cockroaches. This study is aimed at isolating parasitic pathogens responsible for human intestinal parasites from the external surfaces of cockroaches collected from both commercial and residential areas in Perak. The findings indicate a higher prevalence of parasitic infections in American cockroaches from residential areas, with a rate of 75%, as compared to commercial areas where the rate was 40%. The isolation process revealed the presence of eggs and cysts of various parasites, including cestodes, nematodes, and protozoans. Predominantly, Ascaris sp. and Entamoeba sp. were the most common parasites found on the external surfaces of cockroaches in both residential and commercial areas. Our statistical analysis revealed that, there were no significant correlation (P>0.01) between local weather conditions (temperature r=-0.68; P=0.32; rainfall r=0.77; P=0.23) and the number of isolated parasites in the study areas. this suggest that weather factors do not significantly influence the infectivity rate of these parasites on American cockroaches in the study area.
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