RESUMO
Sphingomonas cloacae S-3(T), a nonylphenol (NP)-degrading bacterium, was evaluated for its utility in the remediation of NP-contaminated wastewater. In flask-scale experiments, S-3(T) cells immobilized on porous polypropylene carriers (beads) efficiently degraded NP to concentrations routinely measured in aquatic environments [a few parts per billion (ppb), or micrograms per liter). Therefore, we constructed and evaluated a laboratory-scale wastewater treatment system with a 3-l carrier-filled column. The system worked properly and consistently removed several hundred ppb of NP to ecologically safe concentrations of less than 10 ppb in industrial wastewater without the addition of nutrients. The effect of wastewater pH on the system performance was also evaluated; and wastewater samples with pH values of 6 or 8 were treated efficiently without pH adjustment. These results suggest that a biotreatment system using NP-degrading bacteria can efficiently remediate industrial wastewater and contribute to the preservation of aquatic environments.
Assuntos
Fenóis/metabolismo , Esgotos/microbiologia , Sphingomonas/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , Biomassa , Meios de Cultura , Concentração de Íons de Hidrogênio , Microbiologia Industrial/métodos , Sphingomonas/crescimento & desenvolvimentoRESUMO
An oestradiol-degrading bacterium isolated at a sewage treatment plant in Tokyo was studied phenotypically, genotypically and phylogenetically. Analysis of its 16S rDNA sequence, DNA base composition, whole-cell fatty acid profile and isoprenoid quinone composition, as well as the presence of sphingoglycolipid, revealed that the isolate is a member of the genus Novosphingobium. However, the sequence similarity of its 16S rDNA to those of known Novosphingobium species was no higher than 97%, implying that the isolate is distinctive. The results of DNA-DNA hybridization experiments and physiological characterization also indicated that the isolate represents a novel Novosphingobium species, for which the name Novosphingobium tardaugens sp. nov. is proposed; strain ARI-1T (=JCM 11434T =ATCC BAA-531T =IFO 16725T) is the type strain.