Rhizosphere Diazotrophs and Other Bacteria Associated with Native and Encroaching Legumes in the Succulent Karoo Biome in South Africa
Total and diazotrophic bacteria were assessed in the rhizosphere soils of native and encroaching legumes growing in the Succulent Karoo Biome (SKB), South Africa. These were <i>Calobota sericea</i>, <i>Lessertia diffusa</i>, <i>Vachellia karroo</i>, and <i>W...
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MDPI AG
2022-01-01
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| Series: | Microorganisms |
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| Online Access: | https://www.mdpi.com/2076-2607/10/2/216 |
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| author | Esther K. Muema Emma T. Steenkamp Stephanus N. Venter |
| author_facet | Esther K. Muema Emma T. Steenkamp Stephanus N. Venter |
| author_sort | Esther K. Muema |
| collection | DOAJ |
| description | Total and diazotrophic bacteria were assessed in the rhizosphere soils of native and encroaching legumes growing in the Succulent Karoo Biome (SKB), South Africa. These were <i>Calobota sericea</i>, <i>Lessertia diffusa</i>, <i>Vachellia karroo</i>, and <i>Wiborgia monoptera</i>, of Fabaceae family near Springbok (Northern Cape Province) and neighboring refugia of the Fynbos biome for <i>C. sericea</i> for comparison purposes. Metabarcoding approach using 16S rRNA gene revealed <i>Actinobacteria</i> (26.7%)<i>, Proteobacteria</i> (23.6%)<i>, Planctomycetes,</i> and <i>Acidobacteria</i> (10%), while the <i>nifH</i> gene revealed <i>Proteobacteria</i> (70.3%) and <i>Cyanobacteria</i> (29.5%) of the total sequences recovered as the dominant phyla. Some of the diazotrophs measured were assigned to families; <i>Phyllobacteriaceae</i> (39%) and <i>Nostocaceae</i> (24.4%) (all legumes), <i>Rhodospirillaceae</i> (7.9%), <i>Bradyrhizobiaceae</i> (4.6%) and <i>Methylobacteriaceae</i> (3%) (<i>C. sericea</i>, <i>V. karroo</i>, <i>W. monoptera</i>)<i>, Rhizobiaceae</i> (4.2%; <i>C. sericea, L. diffusa, V. Karroo</i>), <i>Microchaetaceae</i> (4%; <i>W. monoptera</i>, <i>V. karroo</i>), <i>Scytonemataceae</i> (3.1%; <i>L. diffusa, W. monoptera</i>), and <i>Pseudomonadaceae</i> (2.7%; <i>V. karroo</i>) of the total sequences recovered. These families have the potential to fix the atmospheric nitrogen. While some diazotrophs were specific or shared across several legumes, a member of <i>Mesorhizobium</i> species was common in all rhizosphere soils considered. <i>V. karroo</i> had statistically significantly higher Alpha and distinct Beta-diversity values, than other legumes, supporting its influence on soil microbes. Overall, this work showed diverse bacteria that support plant life in harsh environments such as the SKB, and shows how they are influenced by legumes. |
| first_indexed | 2024-03-09T21:24:48Z |
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| language | English |
| last_indexed | 2024-03-09T21:24:48Z |
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| spelling | doaj.art-8f289595b3774173a5959ee24725b0542023-11-23T21:12:40ZengMDPI AGMicroorganisms2076-26072022-01-0110221610.3390/microorganisms10020216Rhizosphere Diazotrophs and Other Bacteria Associated with Native and Encroaching Legumes in the Succulent Karoo Biome in South AfricaEsther K. Muema0Emma T. Steenkamp1Stephanus N. Venter2DSI-NRF Centre of Excellence in Plant Health Biotechnology, Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South AfricaDSI-NRF Centre of Excellence in Plant Health Biotechnology, Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South AfricaDSI-NRF Centre of Excellence in Plant Health Biotechnology, Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South AfricaTotal and diazotrophic bacteria were assessed in the rhizosphere soils of native and encroaching legumes growing in the Succulent Karoo Biome (SKB), South Africa. These were <i>Calobota sericea</i>, <i>Lessertia diffusa</i>, <i>Vachellia karroo</i>, and <i>Wiborgia monoptera</i>, of Fabaceae family near Springbok (Northern Cape Province) and neighboring refugia of the Fynbos biome for <i>C. sericea</i> for comparison purposes. Metabarcoding approach using 16S rRNA gene revealed <i>Actinobacteria</i> (26.7%)<i>, Proteobacteria</i> (23.6%)<i>, Planctomycetes,</i> and <i>Acidobacteria</i> (10%), while the <i>nifH</i> gene revealed <i>Proteobacteria</i> (70.3%) and <i>Cyanobacteria</i> (29.5%) of the total sequences recovered as the dominant phyla. Some of the diazotrophs measured were assigned to families; <i>Phyllobacteriaceae</i> (39%) and <i>Nostocaceae</i> (24.4%) (all legumes), <i>Rhodospirillaceae</i> (7.9%), <i>Bradyrhizobiaceae</i> (4.6%) and <i>Methylobacteriaceae</i> (3%) (<i>C. sericea</i>, <i>V. karroo</i>, <i>W. monoptera</i>)<i>, Rhizobiaceae</i> (4.2%; <i>C. sericea, L. diffusa, V. Karroo</i>), <i>Microchaetaceae</i> (4%; <i>W. monoptera</i>, <i>V. karroo</i>), <i>Scytonemataceae</i> (3.1%; <i>L. diffusa, W. monoptera</i>), and <i>Pseudomonadaceae</i> (2.7%; <i>V. karroo</i>) of the total sequences recovered. These families have the potential to fix the atmospheric nitrogen. While some diazotrophs were specific or shared across several legumes, a member of <i>Mesorhizobium</i> species was common in all rhizosphere soils considered. <i>V. karroo</i> had statistically significantly higher Alpha and distinct Beta-diversity values, than other legumes, supporting its influence on soil microbes. Overall, this work showed diverse bacteria that support plant life in harsh environments such as the SKB, and shows how they are influenced by legumes.https://www.mdpi.com/2076-2607/10/2/216Succulent Karoo Biomelegumes speciesdiazotrophsmetabarcodingrhizosphere soils16S rRNA gene |
| spellingShingle | Esther K. Muema Emma T. Steenkamp Stephanus N. Venter Rhizosphere Diazotrophs and Other Bacteria Associated with Native and Encroaching Legumes in the Succulent Karoo Biome in South Africa Microorganisms Succulent Karoo Biome legumes species diazotrophs metabarcoding rhizosphere soils 16S rRNA gene |
| title | Rhizosphere Diazotrophs and Other Bacteria Associated with Native and Encroaching Legumes in the Succulent Karoo Biome in South Africa |
| title_full | Rhizosphere Diazotrophs and Other Bacteria Associated with Native and Encroaching Legumes in the Succulent Karoo Biome in South Africa |
| title_fullStr | Rhizosphere Diazotrophs and Other Bacteria Associated with Native and Encroaching Legumes in the Succulent Karoo Biome in South Africa |
| title_full_unstemmed | Rhizosphere Diazotrophs and Other Bacteria Associated with Native and Encroaching Legumes in the Succulent Karoo Biome in South Africa |
| title_short | Rhizosphere Diazotrophs and Other Bacteria Associated with Native and Encroaching Legumes in the Succulent Karoo Biome in South Africa |
| title_sort | rhizosphere diazotrophs and other bacteria associated with native and encroaching legumes in the succulent karoo biome in south africa |
| topic | Succulent Karoo Biome legumes species diazotrophs metabarcoding rhizosphere soils 16S rRNA gene |
| url | https://www.mdpi.com/2076-2607/10/2/216 |
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