Malaysian Applied Biology

Preliminary Survey on Population and Daily Activity Pattern of Long-Tailed Macaque (Macaca fascicularis) in Tanjung Datu National Park, Sarawak

2025-04-07T16:56:14+00:00

Long-tailed macaques (Macaca fascicularis) are an endangered species that are facing increasing threats due to habitat fragmentation and limited foraging grounds. Thus, their extensive range of behaviours requires attention from research and management perspectives for their conservation. Studying the behaviour of the M. fascicularis population in Tanjung Datu National Park (TDNP), Sarawak, one of the smallest protected areas that is rich in biodiversity, is crucial for ensuring their conservation success. The purpose of this study was to examine the demographic and behavioural ecology of the long-tailed macaques in TDNP, as there is currently insufficient information available on the M. fascicularis population in the protected area. A population estimation study was conducted using a census walk from February 23rd to March 1st, 2024. The behaviour of M. fascicularis was observed using the scan sampling method during this period. The study was conducted within an area of around 11,222 m², with a total of 181 individuals recorded from two groups. Group A (175 individuals) was recorded near the HQ area, while Group B (6 individuals) was recorded in Telok Upas. No solitary individuals were observed during the study, and due to the direct count method, no variance estimate was calculated. Present results indicated that long-tailed macaques spent most of their time moving (53.79%), followed by resting (14.48%), feeding (13.44%), other activity category (7.93%), vocalisation (5.52%) and grooming (4.83%). Data from the population census and behaviour of the long-tailed macaques can help the park's management in prioritising habitat protection areas and monitoring the population trends for effective long-term conservation of the species within TDNP.

Assessing The Potential Of Indigenous Bacillus cereus For Soil Crack Healing Via Microbiologically Induced Calcium Carbonate Precipitation

2025-10-02T05:31:56+00:00

The utilisation of indigenous ureolytic bacteria for the rehabilitation of soil slope cracks through microbial-induced calcite precipitation (MICP) is cost-effective and eco-friendly. This study was designed to assess the soil's crack-healing potential of the indigenous bacteria, Bacillus cereus. A solution containing the urease-producing B. cereus and B. megaterium (control treatment) and a cementation solution was sprayed onto the cracks; this process was repeated five times. B. cereus treatment induced soil crack repair, with an average reduction in width of 0.20 ± 0.113 mm from the initial width of 0.45 ± 0.187 mm, but the decrease in cracks was not significantly different compared to that observed for B. megaterium. Soil treated with B. cereus contained significantly more CaCO₃ per 20 g of soil (0.78 ± 0.102 g vs. 0.59 ± 0.220 g) compared to B. megaterium and provided optimal growth conditions for the native B. cereus. However, X-ray diffraction analysis revealed that only 1.5% of the precipitated CaCO₃ was in the form of calcite, while aragonite constituted 28.5% and vaterite accounted for 70% of the different crystal structures. B. megaterium was composed of 46% calcite, 24.5% aragonite, and 29.5% vaterite crystals. These findings indicate a positive outlook for the use of indigenous microbial-induced calcite precipitation, especially for fracture repair. Further research is required to determine the mechanism underlying the calcification process of native bacteria and the specific conditions necessary to initiate the formation of calcium carbonate biominerals.

Assessment of Bacterial Contamination and Health Risks Associated With Prolonged Use of Face Masks in Industry Settings

2025-03-27T10:19:46+00:00

Face masks are a critical component of Personal Protective Equipment (PPE) for occupational safety and health management. Nevertheless, prolonged usage of face masks may expose employees to biological contaminants, such as bacteria, which accumulate on the inner surface of the mask and pose potential health risks. This study involved 216 participants employed by a statutory institution in Malaysia. The participants were assigned to wear three types of face masks: cotton, surgical, and Korean filters for durations of four and eight hr during their respective work shifts, which varied across roles such as office workers, trainers, and cleaners. Bacterial isolates from the masks were analyzed using the MALDI-TOF method for species identification. Twelve bacterial species were successfully identified, including Staphylococcus hominis, Staphylococcus epidermidis, Staphylococcus ureilyticus, Bacillus velezensis, Dermacoccus nishinomiyaensis, Bacillus licheniformis, Acinetobacter variabilis, Micrococcus luteus, Bacillus pumilus, Bacillus cereus, Sporosarcina luteola, and Staphylococcus aureus. Most of these species are part of the normal human microbiota but have the potential to act as opportunistic pathogens. Additionally, other bacterial species, particularly spore-forming ones, may have originated from the work environment. To mitigate microbial risks, individuals performing strenuous physical tasks or those with compromised immunity are advised to avoid reusing face masks and to replace them every four hr.

Mitigating Toxicity: Clinical and Pathological Effects of Ensiled Brachiaria decumbens in Sheep

2025-08-04T04:57:00+00:00

Brachiaria decumbens, commonly known as signal grass, is widely used as livestock feed in tropical regions due to its high nutritional value and availability. However, its high concentration of steroidal saponins poses toxicity risks, raising concerns for small ruminant farmers. Therefore, this study aimed to evaluate the effect of feeding ensiled B. decumbens on the health and performance of sheep under tropical conditions. A total of eighteen six-month-old male Dorper cross sheep were used in a feeding trial and assigned to three treatment groups: the control group (T1), fed Pennisetum purpureum; Treatment 2 (T2), fed fresh B. decumbens; and Treatment 3 (T3), fed ensiled B. decumbens. Over the 98-day experimental period, clinical data were collected weekly. At the end of the study, all 18 sheep were slaughtered for morphometric, gross morphology, and histopathological analyses of their organs. The results revealed significant differences (p<0.05) in the health performance of sheep across feeding groups. Sheep in the T3 group, fed ensiled B. decumbens, exhibited slightly higher body weight gain compared to both the T2 group fed fresh B. decumbens and the control group (T1). Additionally, only T2 sheep exhibited pale ocular mucous membranes during the final 21 days of the study. In terms of organ morphometrics, T1 and T3 sheep had lower organ width, length, and weight compared to T2 sheep. Most vital organs appeared grossly normal across all treatments; however, post-mortem examination of T2 sheep revealed lung lesions, including congestion and pus accumulation in the caudal lobes. Histopathological analysis indicated mild to moderate lesions in various organs of T2 sheep fed fresh B. decumbens, whereas no lesions were observed in the T1 and T3 groups. This study concludes that incorporating ensiled B. decumbens into the diet of small ruminants yields more favorable health and performance outcomes than feeding fresh B. decumbens.

Synergistic Cytotoxicity of Natural Gallic Acid from Vitis vinifera and Tamoxifen in Human Osteosarcoma U2OS

2025-10-14T08:10:53+00:00

Osteosarcoma is a prevalent and aggressive bone malignancy, primarily affecting children and adolescents. While tamoxifen (TAM) is a commonly used chemotherapeutic agent, its application is often limited by adverse side effects. Gallic acid (GA), a naturally occurring polyphenol, has demonstrated promising anticancer properties and may offer a safer alternative or adjunct in cancer therapy. This study investigates the effects of GA alone and in combination with TAM on the viability and morphology of human osteosarcoma (U2OS) cells. An in vitro model was employed using the MTT assay to assess cell viability after 72 hr of treatment. The half maximal inhibitory concentration (IC₅₀) and combination index (CI) were calculated to evaluate cytotoxicity and drug interaction. Three combination ratios of GA:TAM (75:25, 50:50 & 25:75) were tested. GA and TAM alone exhibited IC₅₀values of 8.258 ± 1.047 µg/mL and 1.814 ± 1.205 µg/mL, respectively. The 25:75 combination yielded the lowest IC₅₀ (1.475 ± 1.189 µg/mL) and a CI of 0.637, indicating a synergistic effect. Other combinations showed higher IC₅₀ and CI values, suggesting reduced efficacy. Morphological analysis using phase contrast microscopy revealed apoptotic features such as cell shrinkage and rounding in treated cells, particularly in the 25:75 combination group. In conclusion, GA, especially when combined with TAM at a 25:75 ratio, enhances therapeutic efficacy while potentially reducing toxicity. This combination may represent a promising strategy for improving osteosarcoma treatment outcomes.

Vocal Signatures For Species Identification Among Eight Microhylid Frogs in Sarawak, Malaysia

2025-06-21T17:56:28+00:00

The advertisement calls of frogs serve as vital communication signals, playing a significant role in species recognition and mate attraction, representing a critical aspect of their behavioural ecology. This study aims to document and analyse the advertisement calls of eight Microhylidae species in various habitats across Sarawak. Using field recordings and acoustic analysis, distinct call characteristics were identified, including frequency, note repetition rate, and pulse structure. Advertisement calls were recorded and analysed using SoundRuler Acoustic Analysis and Praat Acoustic Software. Call characteristics were subsequently compared for species differentiation. The results showed that each species exhibits distinct call characteristics, likely reflecting adaptations to habitat acoustics and conspecific interactions. Among them, Microhyla nepenthicola Das & Haas, 2010 demonstrated the highest rate of note repetition, the greatest number of pulsed notes per call, and the highest dominant frequency, suggesting unique acoustic adaptations within its ecological niche. These findings can contribute to the understanding of species-specific vocalisations and their potential role in mate selection, territorial defence, and environmental adaptation.

Consumer Perception and Acceptance of Pasteurised Pineapple Juice With Encapsulated Probiotics

2025-08-17T12:48:45+00:00

Fresh pineapple juice is widely appreciated for its numerous health benefits derived from the nutrients in the fruit. Current busy lifestyles have caused many people to prefer ready-to-drink commercial functional juices, such as probiotic-added juice. The probiotics are encapsulated to preserve their bioavailability and survivability in the acidic juice. However, consumer acceptance of this enhanced juice remains uncertain, as the heating process and the addition of encapsulated probiotics may change the juice's sensory parameters (taste, texture, and colour). Therefore, focus group discussion (FGD) sessions (n=18) were conducted to assess consumer perception and acceptance of pasteurised pineapple juice with encapsulated probiotics. The FGD sessions assessed general fruit consumption, safety concerns, and health benefits of taking probiotics. The findings revealed that 100% consumers preferred the safety provided by pasteurisation and the additional health benefits associated with the addition of encapsulated probiotics to the juice. The acceptance of this experimental juice formulation indicates its potential for commercial applications.

Antifungal Activity of Roselle Decoction Residue Extract Against Pestalotiopsis sp.: Valorization of Agro-Industrial Waste

2025-07-04T02:20:45+00:00

This study investigates the antifungal activity of crude ethanolic extracts derived from roselle decoction residues, generated during calyx cordial and juice processing, against Pestalotiopsis sp., a postharvest fungal pathogen associated with fruit rot in wax apples. Valorizing this agro-industrial by-product presents an opportunity to develop sustainable antifungal agents. The experiment evaluated the efficacy of extracts prepared from both fresh and freeze-dried residues, namely roselle calyx (RC), decocted cordial residue (DCR), and decocted juice residue (DJR), at eight different concentrations (10 to 100,000 mg/L) using in vitro and in vivo assays. In vitro results revealed that freeze-dried samples exhibited significantly higher antifungal activity than fresh samples, with complete inhibition observed at lower concentrations (30,000 mg/L) for freeze-dried RC and DCR. DJR showed the lowest efficacy among all calyx sources. In vivo evaluation confirmed that coating wax apples with the most effective extracts reduced disease severity index (DSI) compared to both untreated and chitosan-treated controls. Notably, freeze-dried RC resulted in the lowest DSI, indicating strong protection against fungal infection. The antifungal effects were found to be dose-dependent and involved both fungistatic and fungicidal mechanisms. The superior efficacy of freeze-dried samples is attributed to the better retention of bioactive compounds such as anthocyanins and phenolics, which may disrupt fungal cell integrity and activate plant defense responses. This study supports the use of roselle decoction residues as a low-cost, eco-friendly alternative to synthetic fungicides, aligning with sustainable postharvest disease management strategies.

Floral Trichomes Micromorphology of Selected Hoya R.Br. Species (Apocynaceae) in Peninsular Malaysia

2025-09-02T00:11:48+00:00

Trichomes, which are specialised structures found in the epidermis, are essential for the protection of plants and the secretion of secondary metabolites. This study examines the structures and density of trichomes on the flowers of five selected Hoya species: Hoya callistophylla T.Green., Hoya caudata Hook.f., Hoya elmeri Merr., Hoya maingayi Hook.f. and Hoya parviflora Wight. Through the application of light microscopy (LM) and scanning electron microscopy (SEM), we identified the types, morphology and localisation of trichomes in relation to floral glands. The findings indicated the existence of glandular trichomes, simple trichomes and papillae exhibiting various shapes, including conical, filamentous, finger-like, falcate and stalked capitate apical prostrusion located on the adaxial epidermis of corolla petals and pedicels. This investigation deepens the comprehension of Hoya's floral structure and adds to the taxonomic and ecological insights regarding the genus in Peninsular Malaysia.

Using Elicitors to Induce Curcuminoid Biosynthesis in Curcuma longa Via In Vitro Micropropagation

2026-01-27T05:20:44+00:00

Turmeric (Curcuma longa) is an important herbal plant used in the cosmetic and medical industries. It contains two important products: curcuminoids and volatile oils. Three types of curcuminoids exist: curcumin (the major compound), monodesmethoxycurcumin, and bisdes-methoxycurcumin. Curcuminoids can remedy various diseases such as peptic ulcers, gastric ulcers, dyspepsia, and metabolic and inflammatory conditions. However, monoculture cropping and the practice of rhizome propagation can lead to pathogen contamination, reducing the quality and quantity of curcuminoids. This study aimed to propagate in vitro C. longa plants and improve curcuminoid yield. Rhizomes were propagated using a micropropagation technique, and multiple shoot growth was induced on Murashige and Skoog media supplemented with 5 mgL^-1 kinetin and 1 mgL^-1 BA (8.00±0.58 shoots). Shoots grown on MS media with the addition of 5 µM phenylalanine, 5 µM malonic acid, and a growth retardant (ancymidol) exhibited the highest curcuminoid accumulation (2.31±0.061 µgg-1 dry weight). It can be concluded that the addition of phenylalanine and malonic acid can stimulate curcuminoid biosynthesis. Therefore, supplementing certain precursors, such as leguminous plants and green grasses, as planting material before cultivation can help increase curcuminoid levels.

Length-Weight Relationship Analysis and Condition Factor of Fish in Lake Chini: Reason For Population Depletion

2025-07-11T01:00:16+00:00

Lake Chini's fish are important as a pool of ichthyodiversity of the Pahang River drainage and a natural food resource for the native community nearby. However, the fish population was shrinking after a disastrous flood in 1995, and it is still a puzzle as to the cause of the decline of the fish population. This study aims to estimate the fish growth pattern using the length–weight relationship (LWR) analysis and condition factor. The study evaluated b and K values from the LWR analysis equation. B value is the slope of the LWR, which indicates the growth pattern (e.g., isometric or allometric), while K value refers to the condition factor, which shows the overall health of fish. Fishes were sampled using a gill net and identified to species level, and water quality was analysed using standard methods. Lake Chini was found to have a good to moderate water quality status, ranging from category A to category C according to the Malaysian Lake Water Quality Standard (NLWQS). The Carlson trophic index has classified the lake water bodies into an early eutrophic status. The LWR analysis on four selected fish species showed the mean b value ranged between 2.07 and 4.02, implying negative isometric growth for most of the species and isometric and positive growth for one species, which is K. cryptopterus and C.rapasson respectively. Fish length significantly influenced weight, with coefficients of determination ranging from 69% to 98%. The K value ranged from 1.00 to 1.08, indicating that the fish is in a moderate condition of well-being. This study indicates that water quality, food sources, and habitat are not the significant factors that cause fish depletion in Lake Chini.

Sensory Evaluation and Nutritional Analysis of Keropok Lekor Containing Okara

2025-10-12T05:43:09+00:00

Keropok lekor is a popular Malaysian snack made primarily from fish meat and contains very low fibre. Okara is a soy by-product from the production of soy milk and tofu, and is often discarded as food waste. However, okara is rich in nutrients, containing 55% fibre, 30% protein, 10% fat, and other bioactive components. The incorporation of okara into the production of keropok lekor can help to increase the nutritional content and reduce the environmental impact. This study aimed to evaluate the sensory and nutritional properties of okara-containing keropok lekor. Out of 16 formulations, 5 formulations, including the control, were selected for sensory evaluation: control, formulation 1 (2.7% okara), formulation 2 (5.4% okara), formulation 3 (6.7% okara), and formulation 4 (8.1% okara). The sensory evaluation revealed that formulation 1 received the highest scores for aroma, colour, and appearance and was within the acceptable range for all of these attributes, including overall acceptance. Formulation 1 showed no significant differences in colour, appearance, taste, texture, and overall acceptability compared to the control. Nutrient content of control and formulation 1 showed that fibre (3.25 ± 0.07 g/100 g vs 5.10 ± 0.14 g/100 g), fat (11.05 ± 0.21 g/100 g vs 14.10 ± 0.57 g/100 g) and energy content (289.00 ± 0.01 g/100 g vs 325.00 ± 2.83 g/100 g) increased after incorporation of okara, while moisture (37.20 ± 0.14 g/100 g vs 33.55 ± 0.07 g/100 g) and ash (4.30 ± 0.14 g/100 g vs 2.85 ± 0.21 g/100 g) decreased. In conclusion, keropok lekor, which contains 2.7% okara, exhibits acceptable sensory properties, suggesting that okara can be used in food development to increase dietary fibre content.