AUTHOR=Azli Bahiyah , Razak Mohd Nasharudin , Omar Abdul Rahman , Mohd Zain Nor Azimah , Abdul Razak Fatimah , Nurulfiza I. 

TITLE=Metagenomics Insights Into the Microbial Diversity and Microbiome Network Analysis on the Heterogeneity of Influent to Effluent Water

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.779196

DOI=10.3389/fmicb.2022.779196

ISSN=1664-302X

ABSTRACT=Sanitizing the water sources of local communities is important to control the spread of microbial resistance genes, especially those water-borne human illnesses. The activities of antibiotic resistance genes (ARG)-host pathogens pose threat to public health, and it has been estimated that the infection will lead up to 10 million deaths globally by the year 2050. Hence, in this study, we aim to analyze the efficiency of our municipal wastewater treatment plant (WWTP) process in producing pathogen-free water by investigating the microbial composition between influent and effluent water sites. Shotgun metagenomics sequencing using the Illumina platform was performed onto the influent and effluent samples of six different WWTP sites located in Johore, Malaysia. After raw data pre-processing, the non-redundant contigs library were then aligned against BLASTP for taxonomy profiling and Comprehensive Antibiotic Resistance Database for ARG annotation. Interestingly, the alpha-diversity result had reported effluent site samples to have higher abundance and diverse heterogeneity as compared to the influent site. The Principal Component Analysis (PCA) and Non-multidimensional Scaling (NMDS) plots also suggested effluent sites to have high variation in genetic materials due to loosely clustered sample plots, as compared to the tightly clustered influent samples. This study has successfully identified the top three abundant phyla in influent such as Proteobacteria, Firmicutes and Bacteroidetes, while Proteobacteria, Actinobacteria and Bacteroidetes filled in the top three of effluent sites. Despite the overlapping of top three abundant phyla in influent and effluent sites such as Proteobacteria and Bacteroidetes, the ARG composition heat map and drug class phenotype plot bar managed to exhibit a general trend of downward shift, elucidating the efficiency of WWTP in reducing opportunistic pathogens. Overall, it was demonstrated that our municipal WWTP efficiently eliminated pathogenic microbes from the influent water before its total discharge to the environment, though not with the total elimination of microorganisms. This metagenomics study allowed examination of our water source and showed potential interaction of species and ARG residing in the influent and effluent environment. Both microbial profile structure and co-occurrence network analysis provide integrated understanding regarding the diversity of microorganisms and interactions for future advanced water sanitation treatments.