Abstracts |
The nature of the interactions between microbes and roots of plants in a peaty
soil were studied in a laboratory-based experiment by measuring activities of ss-glucosidase,
phosphatase, N-acetylglucosaminidase, and arylsulphatase. The experiment was based on control
(autoclaved), bacteria-inoculated, and plant (transplanted with Dactylorhiza) treatments, and
samples were collected over 4 sampling intervals. Higher enzyme activities were associated with
the bacteria-inoculated treatment, suggesting that soil enzyme activities are mainly of microbial
origin. For example, ss-glucosidase activity varied between 25-30 mu mol g(-1) min(-1) in the
bacteria-inoculated samples whilst the activity of the control ranged between 4-12 mu mol g(-1)
min(-1). A similar pattern was found for all other enzymes. At the end of the incubation, the
microcosms were destructively sampled and the enzyme activities determined in bulk soil,
rhizospheric soil, and on the root surface. Detailed measurement in different fractions of the
peat indicated that higher activities were found in rhizosphere. However, the higher activities
of ss-glucosidase, N-acetylglucosaminidase, and arylsulphatase appeared to be associated with
bacterial proliferation on the root surface, whilst a larger proportion of phosphatase appeared
to be released from root surface.
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