Young-Gyun Cho

Nocardioides nitrophenolicus sp. nov., a p-nitrophenol-degrading bacterium.

A p-nitrophenol-degrading bacterial strain was isolated from industrial wastewater. This strain (NSP41T) was identified as a member of the genus Nocardioides from chemotaxonomic characterizations and phylogenetic inference based on 16S rDNA sequence analysis. The G + C content is 71.4 mol%. The diamino acid in the cell-wall peptidoglycan is LL-diaminopimelic acid. The predominant menaquinone is MK-8(H4). The cellular fatty acid profile is similar to those of Nocardioides species. 16S rDNA sequence analysis show that strain NSP41T is the most related to Nocardioides simplex strains with a level of nucleotide similarity of 98.6%. The levels of 16S rDNA similarity between strain NSP41T and other Nocardioides species ranged from 93.8 to 95.1%. This organism is distinguishable from some other Nocardioides species as well as N. simplex strains by DNA-DNA relatedness data. This organism is different from N. simplex strains in some phenotypic characteristics. Therefore, on the basis of the data presented, a new species of the genus Nocardioides, Nocardioides nitrophenolicus, is proposed. The type strain of the new species is strain NSP41T (= KCTC 0457BPT).

Anaerobic degradation of pyrrolidine and piperidine coupled with nitrate reduction.

Biodegradability of secondary amines (pyrrolidine, piperidine, piperazine, morpholine, and thiomorpholine) under anaerobic conditions was examined in microbial consortia from six different environmental sites. The consortia degraded pyrrolidine and piperidine under denitrifying conditions. Enrichment cultures were established by repeatedly sub-culturing the consortia on pyrrolidine or piperidine in the presence of nitrate. The enrichments strictly required nitrate for the anaerobic degradation and utilized pyrrolidine or piperidine as a carbon, nitrogen, and energy source for their anaerobic growths. The anaerobic degradation of pyrrolidine and piperidine reduced nitrate to nitrogen gas, indicating that these anaerobic degradations were coupled with a respiratory nitrate reduction.