Inhibition of the fermentation process in soil by acetylene

• Published in: Soil biology & biochemistry Vol. 24; no. 9; pp. 905 - 911
• Main Authors: Flather, D.H., Beauchamp, E.G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1992; New York, NY Elsevier Science
• Subjects: acetylene; Agronomy. Soil science and plant productions; ammonium compounds; anaerobic conditions; Biochemistry and biology; biological activity in soil; Biological and medical sciences; carbon; Chemical, physicochemical, biochemical and biological properties; Clostridium; denitrification; fermentation; Fundamental and applied biological sciences. Psychology; Generalities; glucose; inhibition; nitrates; nitrogen; nitrogen-fixing bacteria; nitrogenase; nutrient sources; Physics, chemistry, biochemistry and biology of agricultural and forest soils; reduction; Soil science; transformation; volatile compounds; wheat straw; Microbial activity; Clostridium butyricum; Hydrogen; Clostridium pasteurianum; Carbon dioxide; Clostridiales; Enzyme inhibitor; Microflora; Metabolic inhibitor; Acetate; Glucose; Fermentation; Acetylene; Butyrate; Silt loam soil; Clostridiaceae; Volatile fatty acid; Bacteria; Anaerobic fermentation
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/0038-0717(92)90013-N

The effect of acetylene on the fermentation of added carbon in anaerobic soil was examined. With glucose as the C source and in the absence of C 2H 2, the fermentation products, acetate and butyrate, were produced in nearly equimolar quantities along with copious quantities of CO 2 and H 2. In the presence of 10 kPa of C 2H 2, there was significant inhibition of acetate, butyrate, CO 2 and H 2 production. The inhibitory effect was significantly greater on butyrate production than acetate production. In the absence of an inorganic N source, added C 2H 2 was reduced to C 2H 4, indicating the activity of the saccharolytic N 2-fixing clostridia. In the presence of NH + 4 (nitrogenase repressed), the inhibition of fermentation due to C 2H 2 appeared to be alleviated. The decrease in butyrate formation is suggested to result from reoxidation of NADH through the reduction of C 2H 2 to C 2H 4 by nitrogenase, rather than by acetyl CoA reduction to butyrate. The potential implications of the use of C 2H 2 in conjunction with N transformations by heterotrophic organisms, in light of these data, are discussed.