Abstract

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Piggery activities necessitate large amount of wastewater generation with high concentrations of organic matter and pathogens. This study characterized the microbial and physicochemical properties of discharged piggery wastewater and its bioremediation potential. Wastewater samples collected weekly from May to July, 2024 at piggery farm, Federal University of Technology Akure, were subjected to microbiological succession analysis and cultivated using pour plate technique. Isolates identified colonially by conventional methods were subjected to 16S rRNA sequencing and phylogeny. Samples’ physicochemical parameters were assessed before and after treatment with dominant isolates using standard methods. Bioremediation was done in four batches; individual isolates, consortium and control. Bacterial growth reduced from 8.36 × 10-1 cfu/ml (day 1) to 1.29 × 10-5 cfu/ml (day 5) at 103 serial dilutions. Fungal growth was recorded only on day 1 (1.3 × 10-5 sfu/ml) at 103 serial dilutions, with no growth detected thereafter. At day 5, most dominant bacterial species were identified as Proteus mirabilis OLU (PX611816) and Pseudomonas aeruginosa OLU (PX614431). Samples bioremediated with P. mirabilis OLU and P. aeruginosa OLU consortium increased pH from 7.15±0.03 to 7.52±0.9, dissolved oxygen level from 4.61±0.02 to 5.81±0.01 mg/ml, and decreased biochemical oxygen demand from 206.42±0.05 to 121.83±0.33 mg/ml and chemical oxygen demand values from 386.94±0.04 to 192.02±0.03 mg/ml. Findings from the study revealed that autochthonous bacterial isolates from piggery wastewater samples has potential to remediate samples with poor microbiological and physicochemical qualities. This suggests a stakeholders’ call for upscale of bioremediation strategies in wastewater treatment.

Keywords: 16S rRNA gene sequencing, bioremediation, microbial composition, physicochemical properties, piggery wastewater