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Rhizobia are bacteria that exhibit both endophytic and free-living lifestyles. Endophytic rhizobial strains are widely known to infect leguminous host plants, while some do infect non-legumes. Infection of leguminous roots often results in the formation of root nodules. Associations between rhizobia and host plants may result in beneficial or non-beneficial effects. Such effects are linked to various biochemical changes that have far-reaching implications on relationships between host plants and the dependent multitrophic biodiversity. This paper explores relationships that exist between rhizobia and various plant species. Emphasis is on nutritional and phytochemical changes that occur in rhizobial host plants, and how such changes affect diverse consumers at different trophic levels. The purpose of this paper is to bring into context various aspects of such interactions that could improve knowledge on the application of rhizobia in different fields. The relevance of rhizobia in sustainable food systems is addressed in context.

Aims: To determine the chemical composition and antibacterial activity of Kenyan Ganoderma lucidum. Study Design: Structural determination of the isolated compound was done using spectral evidences and in comparison with literature. The antibacterial properties of the compound was done using disc diffusion method. Place and Duration of Study: Department of Pure and Applied Chemistry, Masinde Muliro University of Science and Technology, between January and November, 2019. Methodology: Sequential extraction of dried samples of Kenyan G. lucidum were done using solvents hexane, ethyl acetate and methanol. Chromatographic separation of hexane extract of Ganoderma lucidum was done using spectroscopic data. The compound was assayed against Escherichia coli, Klebsiella pneumoniae, Methicillin–Resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Streptococcus pyogenes. Standard antibiotic namely; ampicillin was used as the control. Disc diffusion method was used and zones of inhibition, after respective incubation periods, were used to quantify antibacterial activity. Results: From hexane extract of Ganoderma lucidum, Ergosta-5, 7, 22-triene-3β, 14α – diol (22Z) was isolated. Ethylacetate and methanol extracts produced a mixture of complex compounds. Ergosta-5,7,22-triene-3β,14α-diol (22Z) exhibited significant activity against Methicillin-Resistance Staphylococcus aureus (MRSA) (p=0.022) and Streptococcus pyogenes (p = 0.05). The most sensitive microbe was Streptococcus pyogenes. Conclusion: One major compound, Ergosta-5, 7, 22-triene-3β, 14α – diol (22Z) was isolated, characterized and antibacterial activity determined.

Aim: To screen the Kenyan Ganoderma lucidum for phytochemicals and to investigate it's potential in the management of some disease-causing microbes. Study Design: Hexane, ethyl acetate and methanol extraction; phytochemical study and anti-microbial activities were analysed on Kenyan G. lucidum mushroom. Place and Duration of Study: Masinde Muliro University Science laboratories from January 2019 and March 2019. Methodology: Sequential extraction of dried samples was done using hexane, ethyl acetate and methanol. The crude extracts were assayed against Escherichia coli, Klebsiella pneumoniae, Methicillin-Resistant Staphylococcus aureus (MRSA), Pseudomonas aeroginosa, and Creptococcus neoformans using agar well diffusion method. Ampicillin and nystatin were respectively used as controls for bacteria and fungi. Zones of inhibition measured signified the antimicrobial activity. Results: The following group of compounds were present in the mushroom; terpenoids, carbohydrates, phenolic compounds, glycosides and polyoses. Hexane and methanol extracts showed significant activity at (P= 0.022) against MRSA while ethyl acetate extract was active against Streptococcus pyogenes (P=0.05). Conclusion: Kenyan Ganoderma lucidum contains terpenoids, carbohydrates, phenolic compounds, glycosides, flavonoids and phytosterols. Crude extracts (hexane, ethyl acetate and methanol) were active against MRSA and Streptococcus pyogenes.

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