Industrial wastewaters harbor a unique diversity of bacterial communities revealed by high-throughput amplicon analysis

Abstract

Industrial wastewater effluents present a major source of water pollution, and can potentially alter the microbial ecological landscape. While there are numerous reports on the microbial quality of domestic municipal effluents and their perceived environmental effects, there are limited reports devoted to the study of bacterial diversity of effluents from individual industries before they are mixed up with other sources. This study analyzed both the physicochemical parameters and bacterial community structures of different industrial wastewaters using Illumina high-throughput sequencing platform. Industrial wastewater with temperature ranging from 18.9 to 21.5 °C, and total dissolved solid (TDS) levels at up to 4611 mg/L, appeared to be predominated by Proteobacteria (44.44–75.86%) with the exception of the Capegate sample where Actinobacteria (39.66%) were the highest. Sulfur levels were significantly higher (p < 0.05) in Dixon wastewater constituting higher populations of sulfur reducing bacteria (SRB) compared to the other sites. Diversity index (Shannon-H index) and richness estimator (Chao1 index) ranged from 974 (Capegate) to 4552 (Dixon) and 6.04 (Dixon) to 4.15 (CWI), respectively. Multivariate analysis results highlighted that the bacterial communities were strongly shaped by physicochemical variables. The top 10 operational taxonomic units (OTUs) of each industrial sample had the potential to play important roles in the bioremediation and biodegradation of pollutants. Dominant OTUs belonging to the phyla Planctomyces from the Chemreem sample could not be classified to any genera and are likely to represent novel species.