Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1016/j.soilbio.2011.05.021
Titel (primär) Effects of wood char and activated carbon on the hydrolysis of cellobiose by β-glucosidase from Aspergillus niger
Autor Lammirato, C.; Miltner, A. ORCID logo ; Kästner, M.
Journal / Serie Soil Biology & Biochemistry
Erscheinungsjahr 2011
Department UBT
Band/Volume 43
Heft 9
Seite von 1936
Seite bis 1942
Sprache englisch
Keywords β-glucosidase; Aspergillus niger; Cellobiose; Biochar; Activated carbon; Sorption; Enzymatic activity
Biochar amendments to soils have been suggested as a strategy to sequester carbon and therefore mitigate global climate change. The enrichment of soils with charred materials also increases their fertility. This fertilising effect of biochar may be caused by various mechanisms; an acceleration of nutrient cycling has been suggested as one such mechanism. The rate-limiting step in nutrient cycling is thought to be the extracellular enzymatic attack on biological macromolecules. In this study, therefore, the effects of chestnut wood char (specific surface area 2.0 m2 g−1) and of activated carbon (specific surface area approximately 900 m2 g−1) on an extracellular enzymatic reaction involved in the degradation of cellulose (i.e., hydrolysis of cellobiose by β-glucosidase from Aspergillus niger) were investigated. Cellobiose was not adsorbed by chestnut wood char, whereas activated carbon absorbed more than 97% of it. Both charred materials adsorbed more than 99% of β-glucosidase. For chestnut wood char, adsorption of the enzyme caused a decrease of approximately 30% in the reaction rate, whereas for activated carbon, the nearly complete absorption of both substrate and enzyme entirely inhibited the reaction. These results show that β-glucosidase from A. niger retains most of its activity when adsorbed to chestnut wood char and that the reaction it catalyses in nature is only slightly affected by this charred material. On the other hand, a material characterised by a high specific surface area and high porosity, such as activated carbon, can make even a highly soluble substrate unavailable for soil enzymes and therefore completely inhibit the reaction. Thus, charred materials may affect nutrient cycling mainly by regulating the availability of substrates: the degradation of highly soluble substrates may be accelerated by materials with low specific surface area, which maintain an active and protected enzyme pool, whereas materials with high specific surface and high porosity may slow down the degradation by making substrates unavailable.
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Lammirato, C., Miltner, A., Kästner, M. (2011):
Effects of wood char and activated carbon on the hydrolysis of cellobiose by β-glucosidase from Aspergillus niger
Soil Biol. Biochem. 43 (9), 1936 - 1942