The objective of this study was to evaluate the antifungal activity of essential oil (EO) ofEucalyptus camaldulensisDehnh. against fiveFusariumspp. commonly associated with maize.The essential oil had been extracted by steam distillation in a modified Clevenger-type apparatus from leaves ofE. camaldulensisand their chemical composition characterized by gas chromatography mass spectrometry. Poisoned food technique was used to determine the percentage inhibition of mycelial growth, minimum inhibitory concentration, and minimum fungicidal concentration of the EO on the test pathogens. Antifungal activity of different concentrations of the EO was evaluated using disc diffusion method. The most abundant compounds identified in the EO were 1,8-cineole (16.2%),α-pinene (15.6%),α-phellandrene (10.0%), and p-cymene (8.1%). The EO produced complete mycelial growth inhibition in all the test pathogens at a concentration of 7-8 μL/mL after five days of incubation. The minimum inhibitory concentration and minimum fungicidal concentration of the EO on the test fungi were in the range of 7-8 μL/mL and 8–10 μL/mL, respectively. These findings confirm the fungicidal properties ofE. camaldulensisessential oils and their potential use in the management of economically importantFusariumspp. and as possible alternatives to synthetic fungicides.

Background: Up till now, nomadic communities in Africa have been the primary focus of ethnoveterinary research. Although mainly arable and/or mixed arable/pastoral farmers, Ameru of central Kenya are known to have a rich history of ethnoveterinary knowledge. Their collective and accumulative ethnoveterinary knowledge (EVK) is likely to be just as rich and worth documenting. The aim of the study was to document and analyse the ethnoveterinary knowledge of the Ameru. Methods: Non-alienating, dialogic, participatory action research (PAR) and participatory rural appraisal (PRA) approaches involving 21 women and men aged between 50 and 79 years old were utilized. A combination of snowball and purposive sampling methods were used to select 21 key respondents. The methods comprised a set of triangulation approach needed in EVK for non-experimental validation of ethnoknowledge of the Ameru. Results: A total of 48 plant species distributed in 26 families were documented with details of diseases/ill-health conditions, parts of plants used and form of preparation and administration methods applied to different animal groups. Of these families, Fabaceae had the highest number of species (16.67%), followed by Solanaceae (12.5%), Asteraceae and Euphorbiacea (each comprising 8.33%), Lamiaceae (6.25%), Apocynaceae and Boraginaceae (each comprising 4.17%), while the rest of the 19 families, each was represented by a single plant species. About 30 livestock diseases/ill-health conditions were described, each treated by at least one of the 48 plant species. Most prevalent diseases/ill-health conditions included: - anaplasmosis, diarrhea, East Coast fever, pneumonia, helminthiasis, general weakness and skin diseases involving wounds caused by ectoparasites. Conclusion: The study showed that there was a rich knowledge and ethnopractices for traditional animal healthcare amongst the Ameru. This study therefore provides some groundwork for elucidating the efficacy of some of these plants, plant products and ethnopractices in managing livestock health as further research may lead to discovery of useful ethnopharmaceutical agents applicable in livestock industry.

The objective of this study was to determine the chemical composition and antibacterial activity of essential oils (EOs) ofTagetes minutaagainst three phytopathogenic bacteriaPseudomonas savastanoipv.phaseolicola,Xanthomonas axonopodispv.phaseoli, andXanthomonas axonopodispv.manihotis. The essential oils were extracted using steam distillation method in a modified Clevenger-type apparatus while antibacterial activity of the EOs was evaluated by disc diffusion method. Gas chromatography coupled to mass spectrometry (GC/MS) was used for analysis of the chemical profile of the EOs. Twenty compounds corresponding to 96% of the total essential oils were identified with 70% and 30% of the identified components being monoterpenes and sesquiterpenes, respectively. The essential oils ofT. minutarevealed promising antibacterial activities against the test pathogens withPseudomonas savastanoipv.phaseolicolabeing the most susceptible with mean inhibition zone diameters of 41.83 and 44.83 mm after 24 and 48 hours, respectively.The minimum inhibitory concentrations and minimum bactericidal concentrations of the EOs on the test bacteria were in the ranges of 24–48 mg/mL and 95–190 mg/mL, respectively. These findings provide a scientific basis for the use ofT. minutaessential oils as a botanical pesticide for management of phytopathogenic bacteria.

This study was aimed at evaluating the antibacterial prospective of essential oil (EO) extracted from Toddalia asiatica L. against four pathogenic bacteria. The essential oil was steam-distilled using a modified Clevenger-type apparatus and its chemical composition established by gas chromatography mass spectrometry. Disc diffusion method was used to assess the antimicrobial activity of the essential oil against the test pathogens while tube dilution method was used for the determination of minimum inhibitory concentration and minimum bactericidal concentration of the EO on the test bacteria. The highest activity of the EO was observed against E. coli where a mean inhibition zone of 34.00 mm was recorded at a concentration of 100% followed by B. cereus where a mean inhibition zone of 32.33 mm was recorded at an oil concentration of 50%. The minimum inhibitory concentrations and minimum bactericidal concentrations of the EO on the test pathogens were in the range of 3.13 12.25% and 12.25 >50%, respectively. When compared to tetracycline which was used as the standard, crude essential oil of T. asiatica had significantly higher activity in three out of four studied bacterial strains. These findings justify the continued use of T. asiatica extracts in traditional herbal medicine for the treatment of bacterial-based infections.

Adaptation to a wide variety of habitats allows fungi to develop unique abilities to produce diverse secondary metabolites with diverse bioactivities. In this study, 30 Ascomycetes fungi isolated from St. John’s Island, Singapore were investigated for their general biosynthetic potential and their ability to produce antimicrobial secondary metabolites (SMs). All the 30 fungal isolates belong to the Phylum Ascomycota and are distributed into 6 orders and 18 genera with Order Hypocreales having the highest number of representative (37%). Screening for polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes using degenerate PCR led to the identification of 23 polyketide synthases (PKSs) and 5 nonribosomal peptide synthetases (NRPSs) grouped into nine distinct clades based on their reduction capabilities. Some of the identified PKSs genes share high similarities between species and known reference genes, suggesting the possibility of conserved biosynthesis of closely related compounds from different fungi. Fungal extracts were tested for their antimicrobial activity against S. aureus, Methicillin-resistant S. aureus (MRSA), and Candida albicans. Bioassay-guided fractionation of the active constituents from two promising isolates resulted in the isolation of seven compounds: Penilumamides A, D, and E from strain F4335 and xanthomegnin, viomellein, pretrichodermamide C and vioxanthin from strain F7180. Vioxanthin exhibited the best antibacterial activity with IC₅₀ values of 3.0 μM and 1.6 μM against S. aureus and MRSA respectively. Viomellein revealed weak antiproliferative activity against A549 cells with an IC₅₀ of 42 μM. The results from this study give valuable insights into the diversity and biosynthetic potential of fungi from this unique habitat and forms a background for an in-depth analysis of the biosynthetic capability of selected strains of interest with the aim of discovering novel fungal natural products.

Fungus-growing termites harbour diverse microbial communities in their combs and guts. However, culture-based surveys, cross-colony and cross-regional comparisons and assessments of their antimicrobial activities against entomopathogens and fungal weeds remain limited. Through culture-dependent isolation, we surveyed the bacterial and fungal diversity associated with the combs and guts of termites in the genera Macrotermes and Odontotermes , recovering 600 non- Termitomyces fungal isolates representing 79 genera, as well as 59 bacterial isolates. Pathogenicity tests on Macrotermes gilvus revealed that a Metarhizium isolate obtained from a healthy comb was highly virulent to termites. Combs incubated in the boxes yielded 112 isolates of the weed Xylaria and multi-locus phylogenetic analyses revealed high species diversity. Together, these findings revealed two major microbial threats within healthy termite fungus combs. First, highly virulent entomopathogens that directly threaten termite survival. Second, a diverse assemblage of comb-specialised xylariaceous fungi that persist latently and compete for comb nutrients. Behavioural assays revealed that termites exhibited sharply differential hygienic responses to fungi co-occurring in soil plates, aggressively burying Metarhizium regardless of comb presence, but responded weakly to co-evolved Xylaria . Newly-hatched termites also displayed innate avoidance of food contaminated with Metarhizium conidia. Several comb- and gut-associated bacterial isolates, as well as termite-generated soil boluses, inhibited both Metarhizium and Xylaria in vitro . This study underscores the utility of culture-based approaches for elucidating microbial diversity and ecology in termite nests and highlights the roles of host behaviour and comb- and gut-associated bacteria in suppressing both fungal weed invasions and entomopathogen infections.