Abstract

This study assessed the microbiological characteristics of piggery effluents and receiving soil and surface water across five pig farms (Kono, NNPC Akpajo, Obeakpu, Omagwa, and Rivers State University) in Rivers State, Nigeria. Effluent, surface-water, and soil samples were collected aseptically and analyzed for total heterotrophic bacteria (THB), total coliform (TC), faecal coliform (FC), and fungal counts using standard spread plate techniques. Bacterial and fungal isolates were identified using morphological and biochemical characteristics. High microbial counts were observed across all samples, with THB counts ranging from 5.0 ×10⁷ to 2.9 ×10⁸ CFU/mL in effluents, 1.6×10⁷ to 2.8 ×10⁸ CFU/mL in surface-water, and 1.5 ×10⁷ to 1.3 ×10⁸ CFU/g in soil. Faecal coliform counts ranged from 3.0 x 10³ to 3.2 x 10⁴ CFU/mL for effluent, for surface water it ranged from 6.0 x 10³ to 4.8 x 10⁴ CFU/mL and for soil 4.0 x 10³ to 2.3 x 10⁴ CFU/g. These values exceeded the permissible limits for agro-industry effluent discharge into surface water of <400 MPN/100 mL for total coliforms and <200 MPN/100 mL for faecal coliforms. The dominant bacterial isolates include: Bacillus sp., E. coli, Pseudomonas sp., Klebsiella sp., Serratia sp., Staphylococcus sp., Proteus sp., Enterobacter sp., and Micrococcus sp.  Fungal species identified includes: Aspergillus sp., Candida sp., Mucor sp., Penicillium sp., Rhodotorula sp., Fusarium sp. and Alternaria sp., with Aspergillus species being the most dominant. Isolate distribution varied across piggeries, reflecting farm-specific effluent characteristics. The presence of these potentially pathogenic and opportunistic microorganisms highlights the public health and environmental risks associated with untreated piggery effluents. Proper effluent treatment and management procedures are recommended to mitigate contamination receiving water bodies.