title: Isolation and characterization of a Rhodococcus strain with phenol-degrading ability and its potential use for tannery effluent biotreatment.
abstract: BACKGROUND
  Wastewater derived from leather production may contain phenols, which are highly toxic, and their degradation could be possible through bioremediation technologies.
  
  
  RESULTS
  In the present work, microbial degradation of phenol was studied using a tolerant bacterial strain, named CS1, isolated from tannery sediments. This strain was able to survive in the presence of phenol at concentrations of up to 1,000 mg/L. On the basis of morphological and biochemical properties, 16S rRNA gene sequencing, and phylogenetic analysis, the isolated strain was identified as Rhodococcus sp. Phenol removal was evaluated at a lab-scale in Erlenmeyer flasks and at a bioreactor scale in a stirred tank reactor. Rhodococcus sp. CS1 was able to completely remove phenol in a range of 200 to 1,000 mg/L in mineral medium at 30 ± 2 °C and pH 7 as optimal conditions. In the stirred tank bioreactor, we studied the effect of some parameters, such as agitation (200-600 rpm) and aeration (1-3 vvm), on growth and phenol removal efficiency. Faster phenol biodegradation was obtained in the bioreactor than in Erlenmeyer flasks, and maximum phenol removal was achieved at 400 rpm and 1 vvm in only 12 h. Furthermore, Rhodococcus sp. CS1 strain was able to grow and completely degrade phenols from tannery effluents after 9 h of incubation.
  
  
  CONCLUSIONS
  Based on these results, Rhodococcus sp. CS1 could be an appropriate microorganism for bioremediation of tannery effluents or other phenol-containing wastewaters.
authors.affiliation: Departamento de Biología Molecular, FCEFQyN, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, CP 5800 Río Cuarto (Córdoba), Argentina.
authors.forename: Cintia E
authors.initials: CE
authors.lastname: Paisio
authors.forename: Melina A
authors.initials: MA
authors.lastname: Talano
authors.forename: Paola S
authors.initials: PS
authors.lastname: González
authors.forename: Víctor D
authors.initials: VD
authors.lastname: Busto
authors.forename: Julián Rodríguez
authors.initials: JR
authors.lastname: Talou
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Agostini
mesh_terms: D019149:Bioreactors / Q000382:microbiology; D007220:Industrial Waste; D019800:Phenol / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012240:Rhodococcus / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods
chemical_list: D007220:Industrial Waste; D012336:RNA, Ribosomal, 16S; D019800:Phenol