Les actinomycètes d'un sol salé : rôle des osmoprotecteurs naturels.

Abstract

Actinomycetales strains isolated (34 strains) from sebkha soil of Bazer-Sekra (Setif) (E.C = 11.32 mS/cm) on rich (SCA) and minimum (SMM) medium supplemented with various concentrations of NaCl (0-0,5- 1- 1,5 M), GB (1 mM) and/or extract of halimus were tested for their halotolerance. The effect of NaCl is heterogeneous: if 0,5 M/NaCl increase the growth of several strains, 1M and 1,5M inhibit the majority. In the same conditions the production of antibacterial secondary metabolites by the method of cylinders of agar against aureus and Bacillus subtilis is realized, 22 strains are active while activity is generally inhibited by NaCl. GB and Atriplex halimus extract give a good osmoprotectant for several strains at 0,5 and 1M/NaCl. The of Atriplex halimus extract exceed that of GB. Their use in soils affected by salinity as natural means of osmoprotection can be envisaged.