Partial purification, characterisation and histochemical localisation of alkaline phosphatase from ascocarps of the edible desert truffleTerfezia claveryiChatin

Abstract

In the present paper, we confirmed that alkaline phosphatase (ALP) is the main phosphatase present in ascocarps of the edible mycorrhizal fungus Terfezia claveryi. The enzyme was partially purified by precipitation with polyethylene glycol. The purification achieved from a crude extract was fivefold, with 53% of the activity recovered, and acid phosphatase, most of the lipids and phenolic compounds were eliminated. Alkaline phosphatase was kinetically characterised at pH 10.0, the optimum for this enzyme, using p-nitrophenyl phosphate as substrate. The V(max) and K(m) values were 0.3 micromol.min(-1).mg(-1) protein and 9.0 mM, respectively. Orthovanadate was a competitive inhibitor of ALP, with a K(i) of 42.5 microM. The enzyme was histochemically localised in the peridium, the hypothecium and in the ascogenic hyphae of the gleba using both colour and fluorescent reactions. The results presented suggest that the ascocarp of T. claveryi, at some stages of its development, may become nutritionally autonomous and independent of the host plant.

Mycelium growth stimulation of the desert truffleTerfezia claveryichatin by β‐cyclodextrin

“…On the other hand, the mycelium growth curve observed in the presence of α‐CD was in agreement with the growth model proposed by Coleman et al for several ectomycorrhizal fungi and similar to the growth curves reported by Navarro‐Ródenas et al for T. claveryi in different culture conditions. These growth curves showed an initial lag phase followed by an exponential growth phase and a maximum rate phase, before growth slowed and the colony finally became inactive (Figure ).…”

“…With respect to the colony fresh weight, the results are even more similar, although a slightly higher fresh weight was recorded when β‐CD was added to the culture medium (Table ). Moreover, the data obtained in this work for T. claveryi mycelium growth in the presence of β‐CD are better than those reported previously by Navarro‐Ródenas et al using MMN. These authors obtained data of diameter and growth rate of 1.33 cm and 210 μm day −1 , respectively, much lower than the measurements presented in Table .…”

PARTIAL PURIFICATION AND CHARACTERIZATION OF A CALCIUM‐DEPENDENT ALKALINE PHOSPHATASE FROM THE CYANOBACTERIUM ARTHROSPIRA PLATENSIS 1

“…This ELF solution was shaken and then filtered through a 0.22 lm filter (Millipore, Bedford, MA, USA). Filaments of A. platensis were incubated at room temperature and in the dark for 30 min with 20 lL ELF solution and then washed with 30 mM Tris-HCl pH 8.0 (Navarro-Ródenas et al 2009). Control samples were incubated only with alkaline detection buffer or with ELF solution containing 5 mM EDTA as ALP inhibitor.…”

Bioecology and Uses of Desert Truffles (Pezizales) in the Middle East

“…Moreover, stress induces a change in the mycorrhizal type formed, which is more intracellular under conditions of drought stress for H. almeriense with Terfezia claveryi [28]. Navarro-Rodenas et al [29] suggested that the ascocarp of T. claveryi may, at some development stages, become independent on nutrition from the host plant. In vitro, Lopez-Nicolas et al [30] confirmed the ability of the compound βcyclodextrin to stimulate the mycelial growth of T. claveryi.…”