Characterisation of crude and partially purified peptides with antimicrobial activity from the skin of Bornean frogs

Antimicrobial peptides are one of the most promising antibiotic candidates with the effectiveness in killing the microorganisms, can be found largely in the frog skin. In this study, the antimicrobial properties of the crude and partially purified peptides from the frog skin of Bornean frogs; Chalcorana raniceps, Limnonectes kuhlii, Meristogenys jerboa, Odorrana hosii, Staurois guttatus and Limnonectes leporinus were determined. Crude peptides from the skins of these frogs were partially purified using C18 Sep Pak columns. The antimicrobial activities tested were disc diffusion, minimum inhibitory concentration and minimum bactericidal concentration test. L. leporinus and L. kuhlii peptides displayed the lowest MIC value against P. aeruginosa (62.5 µg/ mL) and S. typhimurium (125 µg/mL). Moreover, L. leporinus peptide showed the lowest MIC value against S. aureus (31.25 µg/mL). Both L. kuhlii and L. leporinus peptides share the lowest MBC value of 125 µg/mL against S. aureus and P. aeruginosa. Peptides from L. kuhlii exhibited the lowest MBC values against MRSA (125 µg/mL), E. coli (62.5 µg/mL) and S. typhimurium (125 µg/mL). It can be concluded that all extracted skin peptides have antimicrobial activity against the selected bacteria, with the skin peptides from L. kuhlii and L. leporinus frogs being more potent than other species studied. The antimicrobial characteristics of peptide samples imply that there is a potential of novel AMPs from the frog species of Borneo. For future study, the peptides of frog skin extracts should be further purified

Nutritional composition,antioxidants and antimicrobial activities in muscle tissues of mud crab,Scylla paramamosain

Mud crab, Scylla paramamosain known as a green mud crab, has become a popular seafood due to its meat quality. In addition, this marine invertebrate has been found to possess peptides with different biological activities and potentials. The aim was, first, to determine the basic nutritional content and second, to screen for the antioxidants and antimicrobials activities in the tissue of mud crab, S. paramamosain. Percentages of carbohydrate, protein and fat in S. paramamosain were 2.32%, 12.53% and 0.23% respectively. The IC50 of methanol extract of tissue S.paramamosain in DPPH scavenging assay was found to be 1.79±0.0 mg/mL. Moreover, superoxide dismutase (SOD) activity was measured as percentage inhibition by SOD was found to be 88.7% ± 2.2, followed by catalase (CAT) activity which was 44.3 ± 2.9 µmol of hydrogen peroxide (H2O2) per minute respectively.The total glutathione (GSH) in the tissues extract was 0.5 µg/mL. In antimicrobial assay, the methanolic extract of S. paramamosain revealed its potential as antimicrobial agents against three human clinical pathogens with minimal inhibitory concentration (MIC) values ranging between 7 to 62 µg/mL. Minimal bactericidal concentration (MBC) values were higher than 125 µg/mL. The study reported that muscle tissues of S. paramamosain are enriched with high protein content and possess antioxidant and antimicrobial activities. Therefore, further studies are needed to identify and isolate the bioactive compounds in the tissue extracts of S. paramamosain to add more values and potentials of mud crabs

Research based Learning through Immersive Face to Face Interaction

Group project for PRK1026 Chemistry II was implemented as researchbased learning through immersive face to face interaction among students and facilitator. The main activities include planning by writing proposal, conducting laboratory activities, interpretation of scientific data, followed by producing a scientific article. All pre-university students are required to complete this project as a team which cover topics related to Chemistry Learning Units in Semester Two

Scienceploration 2023

The Scienceploration Camp is an initiative of the Centre for Pre-University Studies, UNIMAS (PPPU), which aims to increase the interest in science among secondary school students. It is also an effort taken by PPPU towards the achievement of Sustainable Development Goals 4 in providing equal quality education and promoting lifelong learning opportunities for all. On top of that, this camp supports Sarawak’s Digital Economy Strategy in nurturing an integrated ecosystem to foster inclusive digital society, by building the right foundations to grow our local digital economy

Effect of Thermal Treatment on Kelulut Honey Towards the Physicochemical, Antioxidant and Antimicrobial Properties

Heat treatment on commercial honey could deteriorate its quality associated with physicochemical and bioactive capacities. In this study, the effects of thermal treatment (50 °C, 75 °C and 90 °C) on the physicochemical properties (i.e., pH, colour intensity), total phenolic content and total flavonoid content were investigated on the Kelulut honey. The results revealed a significant increase in TFC (0.154 mg QE/g honey) for the heat-treated Kelulut honey compared to the control (0.085 mg QE/g honey). The antioxidant activity of the heat-treated honey revealed an increase in 2, 2- Diphenyl-1-picrylhydrazyl levels by 42%, while the ferric reducing antioxidant power levels were reduced significantly by 22.4% compared to the untreated honey. The antimicrobial activities of heattreated honey declined against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Salmonella typhi bacteria at 75 °C and 90 °C. Based on the effects observed in the bioactive capacities of the heat-treated honey, it is therefore recommended to minimize thermal treatment on the honey during the processing to maintain its natural nutritional quality and benefit consumers