Microbiological Examination and Physicochemical Analysis of Estuary Water Used as a Point of Source Drinking Water

Introduction: Access to potable water is a fundamental human right. However, this is hardly the case in the rural areas of oil producing communities of the Niger Delta.

Aim of Study: The primary aim of this study was therefore to evaluate the physicochemical and microbiological qualities of estuary water used as potable water.

Method: Estuary water samples were collected from Eastern Obolo community in Akwa Ibom State, Niger Delta, Nigeria and analysed for physiochemical using standard techniques, and microbiological parameters using standard cultural and metagenomics techniques. Replicate data from microbiological and physicochemical analyses were analyzed using analysis of variance (ANOVA) while bioinformatic analyses were done using Vecton NTI suite 9 (InforMax, Inc.), NCBI-BLAST-2.2.24 and CLC bio Genomics workbench v7.5.1.

Results: Physicochemical analysis showed that the levels of metals such as chromium, nickel, zinc and iron and as well as turbidity were significantly higher than acceptable standards. Bacterial counts ranged from 0.64 to 1.00 (x 105) cfu/ml. Fungal counts ranged from 2.00 to 4.00 (x 102) cfu/ml. Esherichia coli, Citrobacter, Bacillus, Micrococcus, Pseudomonas and Flavobacterium, Shigella, Salmonella and Vibrio species were isolated using cultural means. Total coliforms counts were higher in location E6 which was closest to the community. Metagenomics analysis gave a total of six kingdoms namely bacteria, unknown, protozoa, archae, plantae and fungi in decreasing order of read counts. Furthermore, it revealed a total of 16 phyla, 24 classes, 38 orders, 39 families and 209 species of bacteria. Some pathogens not captured by cultural means such as Clostridium species, Vibrio alginolyticus, Vibrio neresis, Staphylococcus kloosii, Corynebacterium diptheriae, and uncultured species such as uncultured Helicobacter were all captured by metagenomics.

Conclusion: Although, cultural methods used in this study were able to capture water borne disease pathogens, metagenomics captured much more kingdoms and species. Where possible, both techniques should be used in the microbiological examination of water samples.