Analysis of bacterial composition in slaughterhouse effluent from a major livestock market in Nigeria

Abstract

Effluent discharges are point sources of pollution in aquatic ecosystems. Effluents from slaughterhouses which are often discharged untreated into the receiving ecosystem with potential adverse impacts on the ecosystem. The objective of this study was to evaluate the bacterial community profile of slaughterhouse effluent from a major livestock market in Ogun state, South-West Nigeria. The community DNA was extracted and subsequently sequenced using the illumina platform. The top (5) bacterial phyla accounting for over 94.6% of the sequences in the effluent was dominated by Firmicutes (67%) and the least was Euryarchaeota (3.2%). The top five (5) classes were Clostridia (62.11%), Bacteroidia (15.93%), Bacilli (3.97%), Actinobacteria (3.05%) and Methanobacteria (2.95%). The most abundant orders were Clostridiales (62.10%) Bacteroidales (15.90%), Lactobacillales (3.00%), Actinomyctes (2.70%) and Burkholderiales (1.50%). 52 genera were identified (29.60%) while unclassified genera were 65.90%. The results reveal the bacterial community profile of the effluent constituting genera of pathogenic, biotechnological, environmental, veterinary, and public health importance such as Butyrivibrio, Clostridium, Staphylococcus, Streptococcus, Prevotella, Desulfovibrio, Rhodobacter, among others. The results are of importance for holistic ecological and human health risk assessments as well as targeted interventions and proper treatment of the effluent before discharge. This will support good health and wellbeing, promote clean water and sanitation, as well as sustain life below water; relevant to the United Nations Sustainable Development Goals 3, 6 and 14 respectively.