Abstract
Some soil organic matter fractions inhibited the peroxidase activity of wheat-root filtrates, but the effect was related to the enzyme hydrogen donor used. In the presence of o-dianisidine as the hydrogen donor, humic acid and the fractions obtained from it by water or acid refluxing inhibited the enzyme activity. The greatest effects were produced by those fractions which were insoluble after such treatments. The inhibitory effects were reversible and non-competitive, the Michaelis constant of the enzyme being only slightly affected, and independent of pH of the assay media. When guaiacol was used as the enzyme substrate the inhibitory effects of the humic acid and its fractions were variable and less marked. p-Coumaric and p-hydroxybenzoic acids inhibited peroxidase activity when o-dianisidine was used as substrate, but stimulated the enzyme in the presence of guaiacol. Polymaleic acid which is thought to have a similar structure to fulvic acid, inhibited peroxidase in the presence of both hydrogen donors. whereas fulvic acid was considerably less effective.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
