Vermicomposting is an eco-biotechnological process that transforms energy-rich and complex organic substances into a stabilized humus-like product. In a laboratory experiment, Eisenia fetida (Sav.) earthworms were employed to process putrescible sewage sludges into a high-value biofertilizer, very rich in urease activity and humic-urease complexes (stabilized extracellular enzymes). Extracellular humic-urease complexes were extracted by a single 24-h extraction at 37 °C using neutral pyrophosphate (0.1 M); then, the extracts were dialysed and characterized by means of an analytical isoelectric focusing technique. This technique gave a multiplicity of humic bands enzymatically active, with isoelectric points ranging from 4.8 to 5.6. The results demonstrated that, after an 18-week incubation period, sewage sludge had undergone a biochemical evolution, which caused a doubling of absolute urease activity and a six-fold increase in specific activity (activity with reference to the humic C fraction). The biochemical evolution of the vermicompost was evaluated also from the sharp decrease in pyrophosphate-extractable C and water-soluble C. Stabilization of organic C during vermicomposting and the activity of humic-urease complexes expressed at low pH values are of extreme importance when organic wastes are used in acid soils for biochemical restoration purposes.
This is a preview of subscription content, log in via an institution to check access.
Access this article Subscribe and saveSpringer+ Basic
€34.99 /Month
Price includes VAT (Germany)
Instant access to the full article PDF.
Similar content being viewed by others Explore related subjectsDiscover the latest articles and news from researchers in related subjects, suggested using machine learning. Author information Authors and AffiliationsEstación Experimental de Zaidín, Consejo Superior de Investigaciones Científicas (CSIC), Profesor Albareda 1, P. O. Box 419, 18080 Granada, Spain e-mail: Emilio-Benitez¯eez.csic.es, , , , , , ES
E. Benítez & R. Nogales
Istituto per la Chimica del Terreno, Consiglio Nazionale delle Ricerche (CNR), via F. Corridoni 78, 56125 Pisa, Italy, , , , , , IT
G. Masciandaro & B. Ceccanti
Received: 10 June 1999
About this article Cite this articleBenítez, E., Nogales, R., Masciandaro, G. et al. Isolation by isoelectric focusing of humic-urease complexes from earthworm (Eisenia fetida)-processed sewage sludges. Biol Fertil Soils 31, 489–493 (2000). https://doi.org/10.1007/s003740000197
Issue Date: September 2000
DOI: https://doi.org/10.1007/s003740000197
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4