1Department of Plant Biology, Faculty of Science, University of Douala, Douala, Cameroon
2Laboratory of Soil Microbiology, Biotechnology Centre, University of Yaounde I, Yaounde, Cameroon
3Department of Biological Sciences, University of Ngaoundere, Ngaoundere, Cameroon
4Department of Microbiology, Faculty of Science, University of Yaounde I, Yaounde, Cameroon
American Journal of Microbiological Research.
2015,
Vol. 3 No. 2, 65-75
DOI: 10.12691/ajmr-3-2-5
Copyright © 2015 Science and Education PublishingCite this paper: Ngo Nkot Laurette, Ngo Bisseck Maxémilienne, Fankem Henri, Adamou Souleymanou, Kamguia Kamdem, Ngakou Albert, Nwaga Dieudonné, Etoa François-Xavier. Isolation and Screening of Indigenous Bambara Groundnut (Vigna Subterranea) Nodulating Bacteria for their Tolerance to Some Environmental Stresses.
American Journal of Microbiological Research. 2015; 3(2):65-75. doi: 10.12691/ajmr-3-2-5.
Correspondence to: Ngo Nkot Laurette, Department of Plant Biology, Faculty of Science, University of Douala, Douala, Cameroon. Email:
lnkot@yahoo.frAbstract
Environmental stresses are important limiting factors for crops production. The aim of this experiment is to isolate Legume Nodulating Bacteria (LNB) obtained from root nodules of bambara groundnut (Vigna subterranea L.) plants and evaluate their performance under some environmental constraints. Samples were collected in Cameroon from three location sites of the Humid-forest zone: Logbessou in the Littoral region; Mfoua in the South and Boga in the Centre region. Nodulation of bambara groundnut was examined in plastic bags and root nodules were collected from seedling. After their isolation, the bacteria were confirmed as LNB by re-nodulating Macroptilium atropurpureum. The morphological, cultural and phenotypic characteristics (utilization of carbon, tolerance to salt, pH, aluminium) of isolates were determined. The results obtained were analyzed statistically by ANOVA using the software SPSS analysis version 11.5. Duncan test was used to measure the difference among the means at a level of p<0.05. A collection of 18 isolates was obtained on Yeast Extract Mannitol Agar medium. Authentication experiments, confirmed that the majority of the isolates (66.67%) were LNB due to their ability to infect the host plant. Bambara groundnut isolates are different morphologically. Dendrogram of the phenotypic characteristics showed that, below the boundary level of 50% average similarity, isolates fell into at least three distinct groups. All isolates showed fast-growing capacity. Most isolates (66.67%) were able to grow in a medium with pH as low as and Al concentration of 50 µM (58.33 %). Some isolates (50%) showed weak growth capacity at 4% NaCl. The bambara groundnut isolates tested were able to use a broad range of carbohydrates as sole source of carbon. The isolates from the present study may be useful to increase the symbiotic nitrogen fixation in legume.
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