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 Google Scholar Google Scholar Articles by Tabatabai, M. A. Articles by Singh, B. B. Search for Related Content PubMed Articles by Tabatabai, M. A. Articles by Singh, B. B. Agricola Articles by Tabatabai, M. A. Articles by Singh, B. B.

Rhodanese Activity of Soils¹

ABSTRACT

The detection of rhodanese (enzyme catalyzes the formation of SCN^- from S₂O₃^2- and CN^-) in soils is reported, and a simple method of assaying rhodanese activity in soils is described. This method involves colorimetric determination of the SCN^- produced by rhodanese activity when soil is incubated with buffered (0.05M THAM, pH 6.0) S₂O₃^2- and CN^- solutions and toluene at 37°C for 1 hour. The method developed is rapid, sensitive, and precise. The procedure used to extract SCN^- stops rhodanese activity in soils and gives quantitative recovery of the SCN^- formed. Results showed that steam sterilization and formaldehyde inhibit, sulfate and chloride activate, and toluene has no effect on rhodanese activity in soils. The initial rates of SCN^- formation obeyed zero-order kinetics; in one soil, the rate slowed with time of incubation. The temperature dependence of the rate constant conformed to the Arrhenius equation up to the point of enzyme inactivation (65°C). The activation energy of rhodanese activity of the eight soils studied ranged from 5,160 to 8,110 (avg. 6,690) calories/mole. Studies of other properties of rhodanese activity in soils are reported.

¹ Contribution from the Iowa Agric. & Home Econ. Exp. Stn., Ames as Journal Paper no. J-8343. Project no. 2082.

² Associate Professor and Postdoctoral Research Associate, respectively, Dep. of Agronomy, Iowa State Univ., Ames, 1A 50011.

Received for publication November 10, 1975. Accepted for publication January 6, 1976.

This article has been cited by other articles:

				V. Acosta-Martínez and M.A. Tabatabai Arylamidase Activity of Soils Soil Sci. Soc. Am. J., January 1, 2000; 64(1): 215 - 221. [Abstract] [Full Text]