ISSN: 2471-9315
Maulin Pramod Shah and Reddy GV
Autotrophic ammonia-oxidizing bacteria are a critical factor of the microbial community in industrial wastewater treatment systems. We evaluated the diversity and community composition of β-proteobacterial ammonia-oxidizing bacteria in two full-scale treatment reactors - a sand filter and a biological aerated filter - receive an identical wastewater. Polymerase chain reaction of the 16S rRNA gene fragments of ammonia-oxidizing bacteria-selective primers was merged with denaturing gradient gel electrophoresis to allow the comparative analysis of the dominant ammonia-oxidizing bacteria populations. The phylogenetic affinities of the dominant ammonia-oxidizing bacteria were verified by cloning and sequencing of polymerase chain reaction-amplified 16S rRNA gene fragments. Denaturing gradient gel electrophoresis profiles were evaluated using a probability-based similarity index. An exploitation of a probabilistic index of similarity permitted us to consider the differences and similarities observed in ammonia-oxidizing bacteria community structure in different samples were statistically significant or could be accounted for random matching of bands in denaturing gradient gel electrophoresis profiles that would propose random colonization of the reactors at different ammonia-oxidizing bacteria. All Possibly-like sequences recognized, grouped within the Nitrosomonas genus. A greater diversity of ammonia-oxidizing bacteria were detected in trickling filters than the BAF on all samples analyzed were initiate to be dominated by ammonia oxidizing bacteria most closely linked to Nitrosococcus mobilis. Numerical investigation of the denaturing gradient gel electrophoresis profiles indicated that the ammonia-oxidizing bacteria community in depth profiles from the filter beds was selected in a non-random manner.