Data/hora: 08/06/2024 16:15:13

Provedor de dados: | 69
País: | Chile
Título: | Influence of metal ions and organic carbons on denitrification activity of the halotolerant bacterium, Paracoccus pantotrophus P16 a strain from shrimp pond
Autores: | Pintathong,Punyawatt; Richardson,David J; Spiro,Stephen; Choorit,Wanna.
Data: | 2009-04-01
Ano: | 2009
Palavras-chave: | Metal ions; Nitrate reductase; Nitrite accumulation; Nitrite reductase; Paracoccus pantotrophus.
Resumo: | The effect of metal ions, ferric ion (Fe3+) and molybdenum ion (Mo6+) on the denitrification process of Paracoccus pantotrophus P16 grown under saline conditions was investigated. Results revealed that the dosages of added Fe3+ and Mo6+ significantly accelerated nitrate utilization and nitrite accumulation. Enzymatic studies revealed that the membrane-bound nitrate reductase and the periplasmic nitrite reductase had activities of 998 ± 28 and 373 ± 18 nmol (mg protein)-1 min-1, respectively after growing Paracoccus pantotrophus P16 in medium supplemented with 1.5 µM Fe3+. If provided with 1.5 µM Fe3+and 2.4 µM Mo6+, the membrane-bound nitrate reductase activity increased to 6,223 ± 502 nmol (mg protein)-1 min-1 and the periplasmic nitrite reductase was 344 ± 20 nmol (mg protein)-1 min-1. The results indicated that an addition of Fe3+ and Mo6+ led to an overstimulation of nitrate reductase activity as compared with nitrite reductase activity. When glucose was supplied, the minimal ratio of carbon per nitrate (C/N) was 2.31 mg C/mg NO3--N with denitrification yield of 0.45 g NO3--N/g C. Addition of ethanol instead of glucose, the minimal ratio of C/N was 1.15 mg C/mg NO3--N with denitrification yield of 1.08 g NO3--N/g C.
Tipo: | Journal article
Idioma: | Inglês
Identificador: | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582009000200004
Editor: | Pontificia Universidad Católica de Valparaíso
Formato: | text/html
Fonte: | Electronic Journal of Biotechnology  v.12 n.2 2009