Genotypic and Phenotypic Diversity of Cyanobacteria in Biological Soil Crusts of the Succulent Karoo and Nama Karoo of Southern Africa

• Published in: Microbial ecology 2014-02, Vol.67 (2), p.286-301
• Main Authors: Dojani, Stephanie, Kauff, Frank, Weber, Bettina, Büdel, Burkhard
• Format: Article
• Language: English
• Subjects: Africa, Southern; Biodiversity; Biological and medical sciences; Biological soil crusts; Biological taxonomies; Biomedical and Life Sciences; Biomes; Cloning, Molecular; Cyanobacteria; Cyanobacteria - classification; Cyanobacteria - genetics; Cyanobacteria - isolation & purification; DNA; DNA, Bacterial - genetics; Ecology; Ecosystem; ENVIRONMENTAL MICROBIOLOGY; Fundamental and applied biological sciences. Psychology; Genera; genes; Genotype; Geoecology/Natural Processes; habitats; inventories; Leptolyngbya; Life Sciences; Microbial Ecology; Microbiology; Microcoleus; Nama; Nature Conservation; Oscillatoria; Phenotype; Phormidium; Pseudanabaena; ribosomal RNA; RNA, Ribosomal, 16S - genetics; rRNA genes; Schizothrix; Scytonema; Semiarid lands; semiarid zones; sequence homology; soil crusts; Soil Microbiology; Soil morphology; soil sampling; Soil surfaces; Soils; Species diversity; Taxa; Tolypothrix; Water Quality/Water Pollution
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s00248-013-0301-5

Biological soil crusts (BSCs) are communities of cryptogamic organisms, occurring in arid and semiarid regions all over the world. Based on both morphological identification and genetic analyses, we established a first cyanobacterial inventory using the biphasic approach for BSCs within two major biomes of southern Africa. The samples were collected at two different sites in the Succulent Karoo and one in the Nama Karoo. After cultivation and morphological identification, the 16S rRNA gene was sequenced from the cyanobacterial cultures. From the soil samples, the DNA was extracted, and the 16S rRNA gene sequenced. All the sequences of the clone libraries from soil and cultures were compared with those of the public databases. Forty-five different species were morphologically identified in the samples of the Succulent Karoo (observatories of Soebatsfontein and Goedehoop). Based on the genetic analyses, 60 operational taxonomic units (OTUs) were identified for the Succulent Karoo and 43 for the Nama Karoo (based on 95 % sequence similarity). The cloned sequences corresponded well with the morphologically described taxa in cultures and sequences in the public databases. Besides known species of typical crust-forming cyanobacterial genera (Microcoleus, Phormidium, Tolypothrix and Scytonema), we found sequences of so far undescribed species of the genera Leptolyngbya, Pseudanabaena, Phormidium, Oscillatoria, Schizothrix and Microcoleus. Most OTUs were restricted to distinct sites. Grazed soils showed lower taxa numbers than undisturbed soils, implying the presence of early successional crust types and reduced soil surface protection. Our combined approach of morphological identification and genetic analyses allowed both a taxa inventory and the analysis of species occurring under specific habitat conditions.