Influence of metal ions and organic carbons on denitrification activity of the halotolerant bacterium, Paracoccus pantotrophus P16 a strain from shrimp pond
Electron. j. biotechnol
; 12(2): 4-5, Apr. 2009. ilus, tab
Article
in En
| LILACS
| ID: lil-551365
Responsible library:
CL1.1
ABSTRACT
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 micron M Fe3+. If provided with 1.5 micron M Fe3+and 2.4 micron M 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.
Key words
Full text:
1
Collection:
01-internacional
Database:
LILACS
Main subject:
Artemia
/
Paracoccus pantotrophus
/
Molybdoferredoxin
Language:
En
Journal:
Electron. j. biotechnol
Journal subject:
BIOTECNOLOGIA
Year:
2009
Document type:
Article
/
Project document
Affiliation country:
/
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