Soil dehydrogenases activity was measured as described by Casida et al. [8] with some small modifications.
In general, soil samples of 6g were placed in 16mm x 150 mm test tubes and incubated with 1ml 3% 2,3,5-
triphenyltetrazolium chloride (TTC), 60mg CaCO3 and 2.5ml distilled water at 37oC for 24h. After
incubation the red 2,3,5-triphenyltetrazolium formazan (TPF) was extracted with 50 ml of ethanol and read
colorimetrically at 485nm for quantification. Cellulolytic activity was measured according to Deng and
Tabatabai [1994] with some modifications as given herewith. 5 g of air-dried soil samples were weighed and
rinsed with 1 ml toluene in order to stop microbial growth. Than the samples were suspended in 5ml 10%
carboxymethyl cellulose (CMC - sodium salt) in 50 mM acetate buffer of pH 5.5 and incubated at 30oC for
24 hours. After that the amount of reducing sugars released was determined with the standard Nelson-
Somogyi colorimetric method as described by Deng and Tabatabai [1994]. All determinations were made in
triplicate and expressed on a dry weight basis (DM). Results of dehydrogenase and cellulolytic activities
were expressed as M TPF/g DM . /24h and M glucose ./g DM ./h x 10-3, respectively