Articles
Zamrisham, N.A.F.,
Idrus, S.,
Ismail, S.F.,
Razak, M.S.A.,
Hosseini abari, A.,
Jaman, K.,
Suhartini, S.,
Harun, M.R. Publication Date: 2026
Bioenergy Research (19391242)19(1)
The efficiency of anaerobic digestion (AD) is often constrained by limited microbial attachment surfaces and suboptimal environmental conditions. This study investigates the effectiveness of sodium hydroxide (NaOH)-activated and zinc chloride (ZnCl₂)-activated ceramic bio-rings (CBR) in enhancing biogas production. The objectives are threefold: (1) to evaluate biogas production from landfill leachate (LFL) and food waste (LFW) using Biomethane Potential (BMP) tests with non-activated, NaOH-activated and ZnCl₂-activated CBRs; (2) to compare the performance of NaOH-activated and ZnCl₂-activated CBR in a semi continuous study under varying organic loading rates (OLRs); and (3) to assess the forecasting accuracy of artificial neural networks (ANN) and support vector machines (SVM) in predicting biogas production. NaOH-activated CBR and ZnCl₂-activated CBR underwent sequential thermal treatment at 103 °C and 700 °C to enhance their surface area and pore structure, thereby improving their effectiveness as support media in anaerobic digestion. BMP test C (NaOH-activated CBR) produced a maximum of 5531 mL biogas, a 29% increase over BMP test A (without support). In the semi-continuous study, the NaOH-activated CBR achieved 34% and 32% increases in SMP and biogas yield, respectively, compared to the ZnCl₂-activated CBR. A stable ratio of intermediate-to-partial alkalinity (IA/PA) ratio of 0.25 indicated effective buffering. NaOH activation notably improved surface area (2.56 m2/g) and pore size (2159.03 nm), leading to superior biogas output. In forecasting, SVM outperformed ANN with higher accuracy (R2 = 0.9306 vs. 0.8846). These findings demonstrate that an integrated approach through activated CBR, a novel activation method, and machine learning prediction can enhance anaerobic digestion efficiency for high-strength organic waste. © The Author(s) 2025.
Publication Date: 2025
International Journal of Biological Macromolecules (01418130)331
Upcycling fruit waste into health-promoting ingredients is an urgent sustainability challenge. In this work, a microbial degradation is described that converts apple pectin into bioactive pectic oligosaccharides (POS) using Bacillus subtilis HA1, a strain isolated from traditional yogurt. HA1 is γ-hemolytic, lecithinase-negative, and free of nhe/hbl enterotoxin genes, yet endures acid/bile and adheres to intestinal cells, confirming its safety and probiotic aptitude. The bacterium cleaves pectin within 6 h of incubation, and under optimum conditions (50 °C, pH 6), the extracellular pectinase showed a maximum activity of ≈18 IU/mL. TLC, LC–ESI–MS, and FTIR verify the formation of low-methylated mono- to tri-galacturonic acids. Crude POS scavenge up to 90 % of DPPH radicals at 10 mg/mL, which is five-fold higher than untreated pectin. POS also act selectively against tumor cells: MCF-7 breast cancer viability drops to 17 %, while healthy L-929 and HUVEC cells remain ≥95 % viable. Flow cytometry and qRT-PCR confirm apoptosis via Bax up-regulation and galectin-3 suppression. Altogether, probiotic candidate strains belonging to the B. subtilis afford a safe, eco-friendly route to high-value POS with potent antioxidant and anticancer activities, opening avenues for functional foods, nutraceuticals, and sustainable pectin valorization. © 2025 The Author(s)