AutoriMasciandaro G., Macci C., Doni S., Maserti B.E.**, Calvo-Bado L.***, Ceccanti B., Wellington E.***
AbstractA study was made of the efficiency of three different extractants, 0.1 M sodium pyrophosphate (pH 7),67 mM phosphate buffer (pH 6) and 0.5 M potassium sulphate (pH 6.6), in recovering the proteinquantity and the b-glucosidase enzyme activity from two natural forest soils: (1) an Inceptisoil located inTuscany (Italy) in a mild Mediterranean climate, and (2) a Lithic Calcixeroll soil located in Murcia (southeastof Spain) in a dry-semiarid climate. The pyrophosphate was used to determine the activity ofextracellular-humic-bound proteins, while the phosphate buffer and potassium sulphate were used toextract dissolved extracellular proteins. The latter extractant, after chloroform fumigation, was also usedto measure total proteins in soil. A preliminary screening, using SDS-PAGE in one dimension, was alsocarried out in order to optimize the separation condition of soil proteins extracted with different buffers.To remove the interfering co-extracted substances (humic acid) a purification step using a columnpacked with insoluble polyvinylpyrrolidone was performed. The highest b-glucosidase activity wasrecovered in the pyrophosphate extract, thus confirming its capability of extracting humic-boundb-glucosidase enzyme in a stable and active form. The extractants performed differently with the two soiltypes and band patterns obtained with SDS-PAGE were extractant-specific, demonstrating that each wasselective for a particular class of proteins. Surprisingly, protein bands were also obtained using pyrophosphate,in spite of the very dark extract colour due to the presence of humic substances.
RivistaSoil Biology & Biochemistry
Impact factor
Pagina inizio2156
Pagina fine2161
Autori IBFBiancaelena MASERTI