The crude plant juices of desert plants as appropriate culture media for the cultivation of rhizospheric microorganisms

The exclusive use of plant juices, not as a mere supplement to synthetic culture media, for culturing rhizospheric microorganisms (RMO) is introduced here. Juices were prepared from desert (Mesembryanthemum crystallinum L., Zygophyllum album L., Carpobrotus edulis L.) as well as cultivated (Trifolium alexandrinum L., Beta vulgaris L.) plants. Colonies of RMO (Azospirillum brasilense, Enterobacter agglomerans and Klebsiella pneumoniae) nicely developed on surface-inoculated agar plates prepared from crude and diluted juice of M. crystallinum (ice plant). Furthermore, hundreds of RMO colonies developed on various standard culture media were replicated (>90%) on agar plates of different plant juices. RMO cells grew nicely in liquid ice plant juice, with doubling times comparable to those grown in the reference culture medium. RMO populations resident in various host plants were able to develop on culture media prepared from homologous and heterologous juices. The application of a thin semi-solid overlay agar on the surfaces of inoculated agar plates significantly increased the recovery of micro-colonies on agar plates, particularly those prepared from plant juices.