The aim of this research was to assess the antibacterial and antioxidant properties as well as the variation in metabolites of the cell-free supernatant (CFS) produced by lactic acid bacteria (LAB) from local plants: Lactiplantibacillus plantarum ngue16, L. plantarum ng10, Enterococcus durans w3, and Levilactobacillus brevis w6. The tested strains exhibited inhibitory effects against pathogens, including Bacillus cereus, B. subtilis, Cronobacter sakazakii, Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus using the agar spot assay and well diffusion method. The CFS from all four strains displayed antibacterial activity against these pathogens with minimum inhibitory concentration (MIC) values ranging from 3.12 to 12.5 mg/mL and minimal bactericidal concentration (MBC) values ranging from 6.25 to 25.0 mg/mL. Moreover, the CFS demonstrated resilience within specific pH (3–8) and temperature (60–100 °C) ranges and lost its activity when treated with enzymes, such as Proteinase K and pepsin. Furthermore, the CFS exhibited antioxidant properties as evidenced by their ability to inhibit the formation of two radicals (1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) compared to the negative control, De Man, Rogosa, and Sharpe (MRS) broth. The use of proton-based nuclear magnetic resonance (¹H-NMR) spectroscopy revealed the presence and quantification of 48 metabolites in both the CFS and MRS broths. Principal Component Analysis (PCA) effectively differentiated between CFS and MRS broth by identifying the specific metabolites responsible for the observed differences. The partial least squares (PLS) model demonstrated a significant correlation between the metabolites in the LAB supernatant and the tested antibacterial and antioxidant activities. Notably, anserine, GABA, acetic acid, lactic acid, uracil, uridine, propylene glycol, isopropanol, serine, histidine, and indol-3-lactate were identified as the compounds contributing the most to the highest antibacterial and antioxidant activities in the supernatant. These findings suggest that the LAB strains investigated have the potential to be utilized in the production of functional foods and the development of pharmaceutical products.

Xanthone is an organic compound mostly found in mangosteen pericarp and widely known for its anti-proliferating effect on cancer cells. In this study, we evaluated the effects of xanthone crude extract (XCE) and α-mangostin (α-MG) on normoxic and hypoxic human hepatocellular carcinoma (HepG2) cells and their toxicity towards zebrafish embryos. XCE was isolated using a mixture of acetone and water (80:20) and verified via high performance liquid chromatography (HPLC). Both XCE and α-MG showed higher anti-proliferation effects on normoxic HepG2 cells compared to the control drug, 5-fluorouracil (IC₅₀ = 50.23 ± 1.38, 8.39 ± 0.14, and 143.75 ± 15.31 μg/mL, respectively). In hypoxic conditions, HepG2 cells were two times less sensitive towards XCE compared to normoxic HepG2 cells (IC₅₀ = 109.38 ± 1.80 μg/mL) and three times less sensitive when treated with >500 μg/mL 5-fluorouracil (5-FU). A similar trend was seen with the α-MG treatment on hypoxic HepG2 cells (IC₅₀ = 10.11 ± 0.05 μg/mL) compared to normoxic HepG2 cells. However, at a concentration of 12.5 μg/mL, the α-MG treatment caused tail-bend deformities in surviving zebrafish embryos, while no malformation was observed when embryos were exposed to XCE and 5-FU treatments. Our study suggests that both XCE and α-MG are capable of inhibiting HepG2 cell proliferation during normoxic and hypoxic conditions, more effectively than 5-FU. However, XCE is the preferred option as no malformation was observed in surviving zebrafish embryos and it is more cost efficient than α-MG.

Kajian mengenai kepelbagaian hidupan akuatik air tawar adalah penting untuk memelihara dan memulihara ekosistem mereka. Pelbagai pembangunan infrastruktur telah dijalankan di sekitar kawasan UKM sejak kebelakangan tahun ini boleh menjejaskan keseimbangan ekosistem dan kawasan persekitaran tersebut. Tujuan kajian ini dilakukan adalah untuk mengenalpasti taburan hidupan akuatik di Tasik Ghazali, UKM yang ditangkap menggunakan tiga alatan tangkapan ikan aktif dan pasif. Sebanyak 1,268 sampel hidupan akuatik air tawar berjaya dikumpulkan pada lima aktiviti persampelan yang berbeza. Hasil pencerapan morfologi mengkategorikan hasil tangkapan ini kepada lapan spesies iaitu Poecilia reticulata, Gambusia affinis, Puntius sp., Betta pugnax, Clarias batrachus, Macrobrachium lanchesteri, Macrobrachium malayanum dan Gyraulus sp.. Daripada jumlah ini, spesies ikan yang paling banyak ditangkap adalah Puntius sp.(464) manakala Clarias batrachus merupakan spesies ikan yang paling kurang ditangkap (7). Akhir sekali, jumlah tangkapan hidupan akuatik lain adalah Macrobrachium sp. (294) dan Gyraulus sp. (7).

Super-intensive shrimp culture systems have gained increasing attention due to their ability to support high biomass production under limited water exchange conditions while improving biosecurity and reducing environmental discharge. This study evaluated the growth performance and water quality dynamics of Pacific white shrimp (Penaeus vannamei) cultured under different stocking densities in a commercial-scale super-intensive pond system supplemented with probiotics. Shrimp post-larvae were stocked at 150 PL m⁻² (SD1), 200 PL m⁻² (SD2) and 250 PL m⁻² (SD3) and cultured for 120 days under minimal water exchange conditions. Shrimp growth performance, survival, feed conversion ratio (FCR), alkalinity, nitrogen compounds, biological oxygen demand (BOD) and total suspended solids (TSS) were monitored throughout the culture period. The highest production performance was recorded under SD3 where shrimp achieved a final average body weight of 28.57 g, growth rate of 0.21 g day⁻¹, survival rate of 89.0% and production yield of 41.0 mt ha⁻¹ crop⁻¹. Although greater fluctuations in most of the water quality parameters (alkalinity, ammonia, nitrite, nitrate, BOD, and TSS) were observed in SD2 and SD3, prolonged deterioration of water quality was not evident throughout the culture period. Most ammonia and nitrite concentrations remained below suggested threshold levels despite the substantially higher biomass produced under SD3. Elevated BOD and TSS concentrations observed during the middle culture stage were gradually stabilised towards the later culture period; this suggests that the system retained functional stability under increased organic loading. The relatively stable nitrogen dynamics observed throughout the study indicate that the combined effects of aeration, sludge removal, central drainage, limited water exchange and probiotics-based microbial management contributed to maintaining acceptable environmental conditions under super-intensive culture conditions.