Development of Microbial Bioremediation Products from Mixed Bacterial Consortia for Fat Degradation in Wastewater

Abstract

-rich wastewater from food-processing industries and municipalities causes pipeline blockage, odor, and impaired treatment performance. This study isolated, characterized, and formulated mixed bacterial consortia into bioremediation products and evaluated their efficacy at the laboratory and field scales. Eleven lipolytic isolates were recovered from high-fat wastewater sources by tributyrin agar screening; seven produced clear hydrolysis zones of 26–36 mm. Key strains identified by 16S rRNA gene sequencing were Acinetobacter variabilis BDO3 (lipase activity 8.07 U×mL⁻¹; oil removal 21.7%), Bacillus cereus BDO14 (8.36 U×mL⁻¹; 29.6%), and Lysinibacillus boronitolerans KEO5 (8.02 U×mL⁻¹; 24.5%). Nine consortium formulas were tested in simulated wastewater; the three-strain equal-ratio formula (BDO3:BDO14:KEO5 = 1:1:1) achieved the highest oil removal of 54.1% at day 6, representing an 83–149% improvement over the best monoculture. Scale-up fermentation to 200 L confirmed peak biomass at 48 h, with growth kinetics consistent with those at bench scale. Two product formats were developed: a rice bran–based powder retaining 2.45–6.0 × 10⁶ CFU×mL⁻¹ after 2 months, and a 15% glycerol liquid retaining 1.40–7.5 × 10⁷ CFU×mL⁻¹ after 1 month. Field applications of aquatic food-processing effluent, palm oil mill effluent, and municipal wastewater reduced residual fat to 28.7%, 48.8%, and 34.3%, respectively, within 6 days, outperforming two commercial products (residual fat 92–98%). The developed consortium-based bioremediation product demonstrates strong potential for sustainable, scalable management of fat wastewater at both community and industrial levels.