TY  - CHAP
AU  - López, J.I.
AU  - Navarro, M.
AU  - González, S.
AU  - García, C.
T1  - L-glutaminase Activity of Organic Amendments
LA  - eng
PY  - 2012
SP  - 311
EP  - 323
T2  - Environmental Science and Engineering
SN  - 1863-5539
PB  - Springer Science and Business Media Deutschland GmbH
AB  - High contents of organic matter are present in composts of urban wastes, part of which are easily hydrolysable and mineralisable by soil microorganisms. The metabolic use of this organic fraction depends on the activity of hydrolytic enzymes produced by soil microbial communities, especially those related with N cycle, in which L-glutaminase plays an important role. In this work, L-glutaminase was extracted from compost of the organic fraction of urban solid wastes using pyrophosphate solutions at different molarities, different pHs and under different operational conditions. Optimal conditions for L-glutaminase extraction were 0.2 M sodium pyrophosphate at pH 11, a compost-solution ratio 1:10 (w:v) and 90 min of end-over-end shaking at 4°C. Under these conditions, an important increase in the extracted activity was found compared to the initial L-glutaminase in the compost (81.6 ± 6.9 μg NH4 +–N g−1 compost 3 h−1). Crude extract was fractionated by micro- and ultrafiltration into three molecular fractions: UF1 (MW < 10 kDa), which accumulated soluble low MW-compounds, UF2 (MW > 10 kDa, ϕ < 0.45 μm), with desalted humus-like materials and extracellular proteins and UF3 (ϕ > 0.45 μm), with cell-associated enzymes. All of the molecular fractions displayed L-glutaminase activity, but the extraction using 0.2 M at pH 11, displayed the highest enzymatic activity in the UF1 fraction probably as a consequence of both, cell-lysis and the dissociation of the quaternary structure of the enzyme.
DO  - 10.1007/978-3-642-21162-1_23
UR  - https://investigacion.ubu.es/documentos/60e6a2164edb8e25f92ce031
DP  - Dialnet - Portal de la Investigación
ER  -