METHODS AND RESULTS: The POME final discharge, upstream (unpolluted by POME), and downstream (effluent receiving point) parts of the rivers from two sites were physicochemically characterized. The taxonomic and gene profiles were then evaluated using de novo metatranscriptomics, while the metabolites were detected using qualitative metabolomics. A similar bacterial community structure in the POME final discharge samples from both sites was recorded, but their composition varied. Redundancy analysis showed that several families, particularly Comamonadaceae and Burkholderiaceae [Pr(>F) = 0.028], were positively correlated with biochemical oxygen demand (BOD5) and chemical oxygen demand (COD). The results also showed significant enrichment of genes regulating various metabolisms in the POME-receiving rivers, with methane, carbon fixation pathway, and amino acids among the predominant metabolisms identified (FDR 4, and PPDE > 0.95). This was further validated through qualitative metabolomics, whereby amino acids were detected as the predominant metabolites.
CONCLUSIONS: The results suggest that genes regulating amino acid metabolism have significant potential for developing effective biomonitoring and bioremediation strategies in river water influenced by POME final discharge, fostering a sustainable palm oil industry.
METHODS: Young shoots of E. crassipes, L. flava, and N. oleracea were collected from shallow channels of Puchong (3°00'11.89″N, 101°42'43.12″E), Ladang 10, Universiti Putra Malaysia (2°58'44.41″N, 101°42'44.45″E), and Kampung Alur Selibong, Langgar (06°5'50.9″N, 100°26'49.8″E), Kedah, Peninsular Malaysia. The nutritional values of these macrophytes were analysed by using a standard protocol from the Association of Official Analytical Chemists. Eight replicates of E. crassipes and L. flava and four replicates of N. oleracea were used for the subsequent analyses.
RESULTS: In the proximate analysis, N. oleracea possessed the highest percentage of crude protein (29.61%) and energy content (4,269.65 cal g-1), whereas L. flava had the highest percentage of crude fat (5.75%) and ash (18.31%). The proximate composition trend for each species was different; specifically, all of the species possessed more carbohydrates and fewer crude lipids. All of the species demonstrated a similar mineral trend, with high nitrogen and potassium and lower copper contents. Nitrogen and potassium levels ranged from 12,380-40,380 mg kg-1 and from 11,212-33,276 mg kg-1, respectively, and copper levels ranged from 16-27 mg kg-1. The results showed that all three plant species, i.e., E. crassipes, N. oleracea, and L. flava are plant-based sources of macro- and micronutrient beneficial supplements for human consumption.