title: Salicylic-acid-mediated enhanced biological treatment of wastewater.
abstract: Activated sludge represents a microbial community which is responsible for reduction in pollution load from wastewaters and whose performance depends upon the composition and the expression of degradative capacity. In the present study, the role of salicylic acid (SA) has been evaluated for acclimatization of activated sludge collected from a combined effluent treatment plant followed by analysis of the physiological performance and microbial community of the sludge. The biodegradative capacity of the acclimatized activated sludge was further evaluated for improvement in efficiency of chemical oxygen demand (COD) removal from wastewater samples collected from industries manufacturing bulk drugs and dyes and dye intermediates (wastewater 1) and from dye industry (wastewater 2). An increase in COD removal efficiency from 50% to 58% and from 78% to 82% was observed for wastewater 1 and wastewater 2, respectively. Microbial community analysis data showed selective enrichment and change in composition due to acclimatization by SA, with 50% of the clones showing sequence homology to unidentified and uncultured bacteria. This was demonstrated by analysis of partial 16S rDNA sequence data generated from dominating clones representing the metagenome which also showed the appearance of a unique population of clones after acclimatization, which was distinct from those obtained before acclimatization and clustered away from the dominating population.
authors.affiliation: Environmental Genomics Unit, National Environmental Engineering Research Institute, CSIR, Nehru Marg, Nagpur 440 020, Maharashtra, India.
authors.forename: Anshuman A
authors.initials: AA
authors.lastname: Khardenavis
authors.forename: Atya
authors.initials: A
authors.lastname: Kapley
authors.forename: Hemant J
authors.initials: HJ
authors.lastname: Purohit
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018533:Biomass; D015169:Colony Count, Microbial; D004396:Coloring Agents / Q000302:isolation & purification / Q000378:metabolism; D005838:Genotype; D007221:Industry; D010802:Phylogeny; D020156:Salicylic Acid / Q000494:pharmacology*; D012722:Sewage / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D004396:Coloring Agents; D012722:Sewage; D020156:Salicylic Acid