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Abstract

A new enzyme (isobutylidenediurea amidinohydrolase) catalyzing the hydrolysis of isobutylidenediurea (a condensation product of urea and isobutyraldehyde widely used as a slow-release nitrogeneous fertilizer) was characterized from a strain of Rhodococcus erythropolis. The enzyme was purified 1,250-fold to apparent homogeneity and shown to hydrolyze the fertilizer to urea and isobutyraldehyde at a molar ratio of 2: 1. No activity was observed with ureido- or other structurally related compounds. Its molecular mass was determined by native polyacrylamide gelelectrophoresis and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry to be 15 kDa (+/-2 kDa) and 16.4 kDa, respectively. Growth of the bacterium in the presence of isobutylidenediurea led to an increased expression of the constitutively synthetized enzyme.

Environmental impact of fertilizer use and slow release of mineral nutrients as a response to this challenge

“…30% 42 . It is a crystalline, white solid with low water solubility -nitrogen release from it depends upon the rate of hydrolysis and is not microbe-dependent 43 . Crotonylidene diurea (CDU, 2-oxo-4-methyl-6-ureidohexahydropyrimidine) is a ring-structured product with the total nitrogen content of min.…”