http://hdl.handle.net/10204/887 2013-05-21T09:38:29Z http://hdl.handle.net/10204/6697 Title: The soil and plant determinants of community structures of the dominant actinobacteria in Marion Island terrestrial habitats, Sub-Antarctica Authors: Sanyika, TW; Stafford, W; Cowan, DA Abstract: Marion Island is a Sub-Antarctic island made up of distinct ecological habitats based on soil physiochemical, plant cover and physical characteristics. The microbial diversity and ecological determinants in this harsh Sub-Antarctic environment are largely uncharacterized. Actinobacteria have diverse ecological functions related to soil and plant functioning. This study was aimed at characterizing the diversity and community structures of the dominant actinobacteria in the distinct habitats and to identify their determinant soil and plant characteristics. Using the 16S rRNA gene, the denaturing gradient gel electrophoresis patterns and clone library diversity were correlated with the soil and plant characteristics. Multivariate statistical methods were also used to identify determinant soil and plant characteristics. Salinity and pH were the most important soil determinants, and a number of important site-specific plant species may have been important. The Coastal Fellfield Habitat was dominated by sequences of the suborders Micrococcineae (44%) and Propionibacterineae (18%), with salinity identified as the principal determinant. The Cotula Herbfield Habitat was dominated by Frankineae (37%) and Streptosporangineae (38%), which were correlated with organic nutrient concentrations. The Wet Mire Habitat was dominated by Acidimicrobineae (61%), with moisture and organic carbon content as principal components. Culture-dependent studies were complementary to culture-independent studies with the majority of actinobacteria isolated not identified in 16S rRNA gene clone libraries. This study demonstrates how the soil physiochemical characteristics and plant species independently determine the community structures of the dominant actinobacteria in distinct ecological habitats. These factors subsequently influence their ecological adaptation, roles and functions. Description: Copyright: 2012 Springer Verlag. This is an ABSTRACT ONLY. The definitive version is published in Polar Biology, vol. 35(8), pp 1129-1141 2012-08-01T00:00:00Z http://hdl.handle.net/10204/6683 Title: Evaluation of natural products as potential agrochemical agents with insecticide, fungicide and herbicide activities Authors: Dumontet, V; Litaudon, M; Olivon, F; Poullain, C; Rasoanaivo, C; Stien, D; Eparvier, V; Houël, E; Fokialakis, N; Halabalaki, M; Skaltsounis, AL; Espinosa, A; Olmedo, D; Gupta, M; Fouche, G; Hamburger, M; Sorgenfrei, O; Breuninger, D; Guéritte, F Abstract: The present work aims to identify new promising plant sources, which could be exploited for their agrochemical properties. A total of 484 natural products from academic libraries were selected for screening against four fungal pathogens, five insects and two plants. On the basis of the hits founded and a literature survey, the flora of source countries (New Caledonia, French Guiana, Madagascar, Panama, South Africa and Greece) was analysed for plants containing the desired scaffolds. Lists of 1800 plant part samples were thus established. The plant parts collected generated 3600 extracts that are being evaluated. Description: The International Congress on Natural Products Research, New York City, 28 July - 1 August 2012 2012-07-01T00:00:00Z http://hdl.handle.net/10204/6593 Title: Screening of selected ethnomedicinal plants from South Africa for larvicidal activity against the mosquito Anopheles arabiensis Authors: Maharaj, R; Maharaj, V; Crouch, NR; Bhagwandin, N; Folb, PI; Pillay, P; Gayaram, R Abstract: This study was initiated to establish whether any South African ethnomedicinal plants (indigenous or exotic), that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito larvicidal properties. Description: Copyright: 2012 BioMed Central. Published in Malaria Journal, vol. 11 (320), pp 1-6 2012-09-01T00:00:00Z http://hdl.handle.net/10204/6589 Title: Antioxidant, acetylcholinesterase inhibitory activity and cytotoxicity assessment of the crude extracts of Boophane disticha Authors: Adewusi, EA; Fouche, G; Steenkamp, V Abstract: Traditional healers use Boophane disticha to treat several neurodegenerative diseases. Further studies need to be carried out to justify its use in traditional medicine. Description: Copyright: 2012 African Journal of Pharmacology and Therapeutics, vol. 1(3), pp 78-83 2012-10-01T00:00:00Z