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Title: Effects of nitrate and acetate availability on chloroform production during carbon tetrachloride destruction

Journal Article · · Biotechnology and Bioengineering
;  [1]; ;  [2]
  1. Washington State Univ., Pullman, WA (United States). Chemical Engineering Dept.
  2. Battelle Pacific Northwest National Labs., Richland, WA (United States)

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{sub 2} as the primary end result. 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.

DOE Contract Number:
AC06-76RL01830
OSTI ID:
287532
Journal Information:
Biotechnology and Bioengineering, Vol. 51, Issue 5; Other Information: PBD: 5 Sep 1996
Country of Publication:
United States
Language:
English