biostudies-literatureUnknown49Olayiwola OSPolyhydroxybutyrate (PHB) is a biodegradable polymer produced by bacteria under nutrient-limiting conditions, offering a sustainable alternative to petroleum plastics. This study investigated PHB production by bacterial isolates from plastic-contaminated soils. Forty isolates were screened using Sudan Black B, Nile Blue A, and Nile Red; 12 tested positive, and 11 promising strains belonging to genera, <i>Corynebacterium, Bacillus, Micrococcus, Arthrobacter</i>, and <i>Sinomonas</i> were selected for detailed study. Cultivation in nutrient-limiting medium with 2% sugars (fructose, glucose, sucrose, galactose, mannitol) or agro-wastes (cassava wastewater, cassava and potato peels) revealed strain- and substrate-dependent PHB accumulation, peaking at 24-96 h. <i>Micrococcus</i> sp<i>.</i> OO(14)-5 produced the highest PHB content (0.15 g/L) on mannitol, while <i>Corynebacterium</i> sp. FT(1)-6 and <i>Bacillus</i> sp. GO(10)-6 yielded 3.2-3.4 g/L and ∼60% PHB/CDW on cassava wastewater. Other isolates produced >2.7 g/L on peels. Fourier-transform infrared spectroscopy confirmed PHB. These findings highlight low-cost agro-wastes as effective substrates for sustainable PHB production.Biotechnology reports (Amsterdam, Netherlands)e00941https://www.ebi.ac.uk/biostudies/studies/S-EPMC12907008biostudies-literatureValorization of agricultural residues for bioplastic production by bacteria isolated from plastic dumpsites: Integrating waste streams into the circular bioeconomy.PMC12907008Olayiwola OSOyinloye GOAmoo RAOdeshi TAOdunmbaku EFadipe TOOlaniyi OOfalseValorization of agricultural residues for bioplastic production by bacteria isolated from plastic dumpsites: Integrating waste streams into the circular bioeconomy.Polyhydroxybutyrate (PHB) is a biodegradable polymer produced by bacteria under nutrient-limiting conditions, offering a sustainable alternative to petroleum plastics. This study investigated PHB production by bacterial isolates from plastic-contaminated soils. Forty isolates were screened using Sudan Black B, Nile Blue A, and Nile Red; 12 tested positive, and 11 promising strains belonging to genera, <i>Corynebacterium, Bacillus, Micrococcus, Arthrobacter</i>, and <i>Sinomonas</i> were selected for detailed study. Cultivation in nutrient-limiting medium with 2% sugars (fructose, glucose, sucrose, galactose, mannitol) or agro-wastes (cassava wastewater, cassava and potato peels) revealed strain- and substrate-dependent PHB accumulation, peaking at 24-96 h. <i>Micrococcus</i> sp<i>.</i> OO(14)-5 produced the highest PHB content (0.15 g/L) on mannitol, while <i>Corynebacterium</i> sp. FT(1)-6 and <i>Bacillus</i> sp. GO(10)-6 yielded 3.2-3.4 g/L and ∼60% PHB/CDW on cassava wastewater. Other isolates produced >2.7 g/L on peels. Fourier-transform infrared spectroscopy confirmed PHB. These findings highlight low-cost agro-wastes as effective substrates for sustainable PHB production.2026-01-01T00:00:00Z2026 Mar2026-07-09T11:00:31.395Z2026-07-09T10:37:34.566ZS-EPMC129070084170444110.1016/j.btre.2025.e00941