Biocompatibility and ecotoxicity concerns associated with chemically produced metallic nanoparticles have led to an increasing interest in the development of environmentally benign alternatives for nanoparticle synthesis using biological platforms. Herein, we report the utilization of an extract of seed-derived callus of Catharanthus roseus for the production of stable silver nanoparticles (Ag NPs). The bioreduction of silver ions was evident from UV-Vis spectroscopy results: the absorption maxima were observed at 425 nm, indicative of elemental silver. Transmission electron micrographs revealed that the Ag NPs were well-dispersed and predominantly spherical with particle sizes in the range of 2-15 nm. The synthesized Ag NPs exhibited colloidal stability in an aqueous dispersion for a period of 120 days, as indicated by UV-Vis absorbance spectra and zeta potential measurements. Fourier transform infrared spectroscopy revealed the possible utilization of hydroxyl groups and amides in the reduction of silver ions and surface stabilization of the Ag NPs, respectively. Notably, the synthesized Ag NPs showed considerable antibacterial action against Escherichia coli even after 8 weeks of storage under ambient conditions. Thus, cell extracts of cultured callus of Catharanthus roseus could be explored as an ecofriendly platform for the synthesis of stable and functional nanoparticles.

Invasive fungal diseases are associated with significant morbidity and mortality, particularly in immunocompromised individuals. Early and accurate diagnosis is crucial for effective treatment. Despite traditional methods such as microbiological culture, histopathology, radiology and direct microscopy are available, antigen/antibody‐based diagnostics are emerging for diagnosis of invasive fungal infections (IFI). Fungal cell wall is a unique structure composed of polysaccharides that are well correlated with fungal burden during fungal infections. Based on this feature, cell wall polysaccharides have been explored as antigens in IFIs diagnostics such as the galactomannan assay, mannan test, β‐glucan assay and cryptococcal CrAg test. Herein, we provide an overview on the cell wall polysaccharides from three opportunistic pathogens: Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans, and their applications for IFIs diagnosis. The clinical outcome of newly developed cell wall polysaccharides‐based diagnostics is also discussed.

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Agricultural production and the agro-food industry furnish large volumes of solid wastes, which when unutilized could lead to environmental pollution. An attempt was made to utilize wastes from the oil palm and timber industries for the cultivation of Lentinus squarrosulus, a Nigerian edible mushroom. Mahogany sawdust (MSD), Gmelina sawdust (GSD), oil palm fruit fibre (OPFF) and oil palm empty fruit bunch (OPEFB) significantly influenced crop cycle time, yield, nutritional properties and market quality of the mushroom. The shortest crop cycle time achieved (47 days) was with Gmelina sawdust. Oil palm fruit fibre proved a better substrate for the production of mushrooms with higher yields and protein content (30.10 g/kg substrate and 27.42%). Yield and protein content of harvested mushrooms were strongly correlated with the nitrogen content of the substrates. Fruit bodies with the lowest fat content were harvested from Gmelina sawdust. Fat contents of the mushrooms showed a positive and significant correlation with the cellulose content of the waste. Oil palm fruit fibre yielded the highest quality mushrooms, with 26% in the >7 cm group while GSD and OPEFB had 0% in the same quality group. Considering the desirable characteristics of yield, protein content and market quality, OPFF proved to be a good substrate which could be exploited for large scale production of L. squarrosulus.

Development of efficient substrate formulas to improve yield and shorten production time is one of the prerequisites for commercial cultivation of edible mushrooms. In this study, fifteen substrate formulas consisting of varying ratios of palm press fibre (PPF), mahogany sawdust (MS), Gmelina sawdust, wheat bran (WB), and fixed proportions of 1% calcium carbonate (CaCO3) and 1% sucrose were assessed for efficient Lentinus squarrosulus production. Proximate compositions of mushrooms produced on the different substrate formulas were also analysed and compared. Substrate formulations containing 85% PPF, 13% WB, 1% CaCO3, and 1% sucrose were found to produce the highest carpophore yield, biological efficiency and size (206.5 g/kg, 61.96%, and 7.26 g, respectively). Days to production (first harvest) tended to increase with an increase in the amount of WB in the substrate formulas, except for PPF based formulas. The addition of WB in amounts equivalent to 8~18% in substrate formulas containing 80~90% PPF resulted in a decrease in the time to first harvest by an average of 17.7 days compared to 80~90% MS with similar treatment. Nutritional content of mushrooms was affected by the different substrate formulas. Protein content was high for mushrooms produced on formulas containing PPF as the basal substrate. Thus, formulas comprising PPF, WB, CaCO3, and sucrose at 85% : 13% : 1% : 1%) respectively could be explored as starter basal ingredients for efficient large scale production of L. squarrosulus.

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