title: Bacterial profiling in brine samples of the Emalahleni Water Reclamation Plant, South Africa, using 454-pyrosequencing method.
abstract: A metagenomic approach was applied using 454-pyrosequencing data analysis for the profiling of bacterial communities in the brine samples of the water reclamation plant. Some physicochemical characteristics of brine samples were also determined using standard methods. Samples ranged from being lightly alkaline to highly alkaline (pH 7.40-10.91) throughout the various treatment stages, with the salinity ranging from 1.62 to 4.53 g L(-1) and dissolved oxygen concentrations ranging from 7.47 to 9.12 mg L(-1). Phenotypic switching was found to occur due to these physicochemical parameters. Microbial diversities increased from those present in Stage I reactor (six taxonomic groups) to those in Reverse Osmosis (RO) stage I (17 taxonomic groups), whereas in the second phase of the treatment, it increased in Stage II clarifier (14 taxonomic groups) followed by a decrease in RO stage II (seven taxonomic groups). Overall, seven phyla were detected, apart from many bacterial sequences that were unclassified at the phylum level. The most dominant phylum found was Proteobacteria accounting for 59% of the total sequences. A blastn sequence similarity search showed that the majority of the sequences (56%) were homologous to the uncultured bacterial species, underlining the vast untapped bacterial diversity.
authors.affiliation: Department of Environmental, Water and Earth Sciences, Water Care Unit, TUT, Pretoria, South Africa.
authors.forename: Sudharshan
authors.initials: S
authors.lastname: Sekar
authors.forename: Armand A E A
authors.initials: AA
authors.lastname: Zintchem
authors.forename: Jitendra
authors.initials: J
authors.lastname: Keshri
authors.forename: Ilunga
authors.initials: I
authors.lastname: Kamika
authors.forename: Maggy N B
authors.initials: MN
authors.lastname: Momba
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics*; D058448:Biota; D004783:Environmental Microbiology; D059014:High-Throughput Nucleotide Sequencing; D006863:Hydrogen-Ion Concentration; D056186:Metagenomics; D054712:Salinity; D012492:Salts / Q000737:chemistry; D017422:Sequence Analysis, DNA; D013019:South Africa; D018508:Water Purification
chemical_list: D012492:Salts; C017082:brine
keywords: acid mine drainage; brine; halophilic bacteria