title: Decomposition of (14)C-labeled cellulose substrates in litter and soil from a beechwood on limestone.
abstract: The decomposition of three different (14)C-labeled cellulose substrates (plant holocellulose, plant cellulose prepared from (14)C-labeled beech wood (Fagus sylvatica) and bacterial cellulose produced by Acetobacter xylinum) in samples from the litter and mineral soil layer of a beechwood on limestone was studied. In a long-term (154 day) experiment, mineralization of cellulose materials, production of (14)C-labeled water-soluble compounds, and incorporation of (14)C in microbial biomass was in the order Acetobacter cellulose > holocellulose > plant cellulose in both litter and soil. In general, mineralization of cellulose, production of (14)C-labeled water-soluble compounds, and incorporation of (14)C in microbial biomass were more pronounced, but microbial biomass (14)C declined more rapidly in litter than in soil. In short-term (14 day) incubations, mineralization of cellulose substrates generally corresponded with cellulase and xylanase activities in litter and soil. Pre-incubation with trace amounts of unlabeled holocellulose significantly increased the decomposition of (14)C-labeled cellulose substrates and increased cellulase activity later in the experiment but did not affect xylanase activity. The sum of (14)CO2 production, (14)C in microbial biomass, and (14)C in water-soluble compounds is considered to be a sensitive parameter by which to measure cellulolytic activity in soil and litter samples in short-term incubations. Shorter periods than 14 days are preferable in assays using Acetobacter cellulose, because the decomposition of this substrate is more variable than that of holocellulose and plant cellulose.
authors.affiliation: II Zoologisches Institut, Abteilung Ökologie, Berliner Strasse 28, W-3400, Göttingen, F.R. Germany.
authors.forename: S
authors.initials: S
authors.lastname: Scheu
authors.forename: S
authors.initials: S
authors.lastname: Wirth
authors.forename: U
authors.initials: U
authors.lastname: Eberhardt