Effects of oxygen on denitrification in marine sediments

✍ Scribed by Patricia Bonin; Nathalie Raymond

• Publisher: Springer
• Year: 1990
• Tongue: English
• Weight: 633 KB
• Volume: 207
• Category: Article
• ISSN: 1573-5141
• DOI: 10.1007/bf00041447

✦ Synopsis

Experiments were carried out to determine the effect of oxygen on denitrification, simultaneously in sediment and in a bacterial strain isolated from this sediment. Descriptions of the apparatus used are given. In sediment, denitrification was found to occur when the oxygen concentration increased to 5 mg l-', but the activity was only 10% of that obtained under anaerobic conditions. The two first steps of denitrification measured in the sediment were less sensitive to oxygen. When the sediment was incubated in presence of 1,l mg l-' O,, the denitrification rate was never fully restored by returning it to anaerobic conditions.

In cell suspensions of the denitrifying bacteria: Ps. nautica isolated from the sediment, denitrilication was equally strongly influenced by oxygen. The different steps of denitrification, nitrate, nitrite and nitrous oxide reduction, were differently affected with respect to oxygen concentration. The nitrate reduction was less sensitive than nitrite and nitrous oxide reduction.