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Effects of nitrate and acetate availability on chloroform production during carbon tetrachloride destruction
Author(s) -
Sherwood Juli L.,
Petersen James N.,
Skeen Rodney S.,
Valentine Nancy B.
Publication year - 2000
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/(sici)1097-0290(19960905)51:5<551::aid-bit7>3.0.co;2-b
Subject(s) - denitrifying bacteria , nitrite , nitrate , chemistry , electron acceptor , chloroform , carbon tetrachloride , inorganic chemistry , environmental chemistry , organic chemistry , denitrification , nitrogen
Fed batch experiments were performed to test the effects of electron donor and electron acceptor availability on the production of chloroform (CF) during carbon tetrachloride (CT) destruction by a denitrifying bacterial consortium. In one series of tests, acetate (electron donor) was present in excess while nitrate and nitrite (electron acceptor) were limiting. In the other series of tests, acetate was the limiting nutrient, and nitrate and nitrite were in excess. Under nitrate limiting conditions, 50% (±17%) of the CT transformed by the microorganisms was converted to CF. However, under acetate limiting conditions, only 4% (±4%) of the CT that was degraded appeared as CF. Previous research had suggested that denitrifying bacteria can degrade CT via two competing pathways. One of these pathways produces CF as the predominant end product. The second pathway produces CO 2 as the primary end product. The results shown here suggest that the first pathway is dominant when nitrate and nitrite are depleted while the second pathway, which produces little CF, dominates when nitrate or nitrite are available.