Determination of the β-Glucosidase Activity in Different Soils by Pre Capillary Enzyme Assay Using Capillary Electrophoresis with Laser-Induced Fluorescence Detection

PATRICIA W. STEGE; GERMÁN A. MESSINA; GUILLERMO BIANCHI; ROBERTO A. OLSINA

JOURNAL OF FLUORESCENCE

SPRINGER/PLENUM PUBLISHERS

Año: 2010 vol. 20 p. 517 - 523

1053-0509

Abstract Enzyme activities can provide indication forquantitative changes in soil organic matter (SOM). It isknown that the activities of most enzymes increase as nativeSOM content reflecting larger microbial communities andstabilization of enzymes on humic materials. β-Gucosidase(β-Glu) activities have been frequently used as indicators ofchanges in quantity and quality of SOM. In this study wepropose a simple and very sensitive method, which has lowerlimit of detection compared with classic spectrophotometricmethod with the aim of determinate the β-Glu activity in soilsamples using Fluorescein mono-β-D-glucopyranoside(FMGlc) as a substrate. The fluorescein released by theenzymatic reaction was quantified by capillary electrophoresislaserinduced fluorescence (CE-LIF) method. The backgroundelectrolyte (BGE) consisted in 40mMphosphate buffer, pH 6.The LOD and LOQ for fluorescein were 1.3 10−7 mg mL−1and 6.4 10−6 mg mL−1, respectively. This work deals withthe minimization of the mixture for the enzymatic reactionand with the optimization conditions of CE separation. Tothe best of our knowledge, this is the first time that anenzymatic activity was detected in soil using CE-LIF system.