Isolation and submerged culture biomass production of the arid land cyanobacteria Microcoleus spp., an investigation on its utilization for biological soil crust restoration

Abstract

Biological soil crust (BSC) restoration could effectively contribute in reducing several adverse environmental impacts such as soil erodibility. The usefulness of the microorganism constituent of the arid land (e.g., desert land cyanobacteria Microcoleus) for the BSC restoration has already been introduced, not only by laboratory studies but also by many other field investigations. In order to isolate the soil cyanobacteria with a potential to support BSC succession, soil samples from the southwestern dry lands in Iran were taken, soils serial dilution was prepared and submerged, and streaking-plate methods were applied. The newly isolated native cyanobacterium was identified as the Microcoleus on the genus level following the standard references. The isolated cyanobacterium was cultured phototrophically using five different media consisting of BBM, BG-11, F/2, Jourdan, and artificial wastewater submerged batch. Microcoleus spp. was found in all sites soil samples. The maximum biomass was achieved in the Jourdan submerged culture medium with an amount of 0.88 g/L. The cell density in this culture medium was increased up to 20 times of the initial cell density during 7 days of the cultivation. The specific biomass growth rate was calculated to be in a range of 0.03–0.057 per day. The preliminary experiments and reported restoration activities of Microcoleus submerged cultures were shown to have the potential for providing the soil with the inoculant for the restoration of the degraded arid lands such as Middle East region.