HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (23) Citing Articles via Google Scholar Google Scholar Articles by Bichat, F. Articles by Sims, G. K. Search for Related Content PubMed Articles by Bichat, F. Articles by Sims, G. K. GeoRef GeoRef Citation Agricola Articles by Bichat, F. Articles by Sims, G. K.

Microbial Utilization of Heterocyclic Nitrogen from Atrazine

Dep. of Natural Resources and Environmental Sciences, Univ. of Illinois, 1102 S. Goodwin Ave, Urbana, IL 61801

G. K. Sims^*

USDA-ARS, 1102 S. Goodwin Ave, Urbana, IL 61801

*Corresponding author (gk-sims{at}uiuc.edu)

ABSTRACT

Radiotracer studies have provided indirect evidence that heterocyclic N in atrazine [2-chloro-4(ethylamino)-6-(isopropylamino)-1,3,5-triazine] may be utilized by microorganisms as a source of N; however, no data are available from investigations using ¹⁵N as a tracer. Studies were conducted to examine microbial utilization of atrazine ring-¹⁵N in soil and pure cultures of Pseudomonas sp. strain ADP, Agrobacterium radiobacter J14a, or bacterium M91-3. Atrazine [U-¹⁵N-ring] was synthesized from labeled urea. To investigate the effect of exogenous N on atrazine degradation, pure cultures were supplemented with unlabeled atrazine and labeled N as (NH₄)₂SO₄, KNO₃, urea, or glycine. Under C-limiting conditions, cells of Pseudomonas sp. strain ADP incorporated side chain-N into biomass and liberated ring-N as NH₄. When N was limiting, ring-N was also recovered in biomass. Degradation of atrazine by Pseudomonas strain sp. ADP and A. radiobacter was unaffected by the presence of exogenous N, whereas no degradation occurred with bacterium M91-3 in media containing urea or NH₄-N. The fate of double-labeled [U-¹⁴C, U-¹⁵N-ring]-atrazine (15 mg kg^-1) was examined after incubation of a Bloomfield soil (sandy, mixed, mesic Psammentic Hapludalf) amended with NH₄- or NO₃-N (75 mg kg^-1), with or without an inoculum of Pseudomonas sp. strain ADP (1.06 x 10¹³ cells kg^-1). In uninoculated soil, mineralization of atrazine-¹⁴C was inhibited by inorganic N, whereas in the inoculated soil, 87% of the atrazine was mineralized, regardless of the N treatment. The C/N ratio was much lower for amino acids isolated from soil than for the atrazine ring, suggesting preferential assimilation of N over C by microorganisms.

Received for publication January 26, 1998.

This article has been cited by other articles:

				V. Garcia-Gonzalez, F. Govantes, O. Porrua, and E. Santero Regulation of the Pseudomonas sp. Strain ADP Cyanuric Acid Degradation Operon J. Bacteriol., January 1, 2005; 187(1): 155 - 167. [Abstract] [Full Text] [PDF]

				V. Garcia-Gonzalez, F. Govantes, L. J. Shaw, R. G. Burns, and E. Santero Nitrogen Control of Atrazine Utilization in Pseudomonas sp. Strain ADP Appl. Envir. Microbiol., December 1, 2003; 69(12): 6987 - 6993. [Abstract] [Full Text] [PDF]

				E. Topp, H. Zhu, S. M. Nour, S. Houot, M. Lewis, and D. Cuppels Characterization of an Atrazine-Degrading Pseudaminobacter sp. Isolated from Canadian and French Agricultural Soils Appl. Envir. Microbiol., July 1, 2000; 66(7): 2773 - 2782. [Abstract] [Full Text]