title: Microbial degradation of seven amides by suspended bacterial populations.
abstract: Microbial transformation rate constants were determined for seven amides in natural pond water. A second-order mathematical rate expression served as the model for describing the microbial transformation. Also investigated was the relationship between the infrared spectra and the second-order rate constants for these amides. Second-order rate constants (k2) ranged from a low of 2.0 X 10(-14) to a high of 1.1 X 10(-9) liters organism-1 h-1 for niclosamide (2',5-dichloro-4'-nitrosalicylanilide) and propachlor (2-chloro-N-isopropylacetanilide), respectively. The mechanism of degradation (i.e., microbially mediated hydrolysis) of the amides was consistent with that of other organic chemicals previously studied in a variety of natural waters. Preliminary investigations indicate that temporal variations in measured second-order rate constants are small. A simple linear regression of the infrared carbonyl-stretching frequency with log K2 gave a correlation coefficient (r2) of 0.962.
authors.affiliation: Environmental Research Laboratory, U.S. Environmental Protection Agency, Athens, Georgia 30613-7799.
authors.forename: W C
authors.initials: WC
authors.lastname: Steen
authors.forename: T W
authors.initials: TW
authors.lastname: Collette
mesh_terms: D000577:Amides / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D055598:Chemical Phenomena; D002621:Chemistry; D006868:Hydrolysis; D007700:Kinetics; D008954:Models, Biological; D015394:Molecular Structure; D012044:Regression Analysis; D013055:Spectrophotometry, Infrared; D014871:Water Microbiology
chemical_list: D000577:Amides