Research articles

Light filtration technology for sustainable microalgal biomass production

2026-06-15T13:09:13Z

Light filtration technology for sustainable microalgal biomass production Sero, Emmanuel Tapiwa; Siziba, Nqobizitha; Bunhu, Tavengwa; Shoko, Ryman The use of native microalgal strains, which are well adapted to local environmental conditions, for sustainable biofuels production has largely been marred by photonics-related challenges. To date, most photobioreactor systems make use of artificial sources of illumination thus increasing the overall costs of biomass production. Solar energy, although sustainable and cost-effective, is difficult to manage and control. It also contains other wavelengths which are detrimental to microalgae. Thus, this study sought to make use of spectral filters for optimal outdoor algaculture. Hence, solar energy was used in wastewater-mediated algaculture of native and imported Chlorella sp. under blue, green, red and yellow coloured spectral filters. The native Chlorella sp. had the highest growth rate of 0.892 d−1 and 0.754 d−1 under green and blue coloured filters, respectively. In comparison, the imported Chlorella strain had a growth rate of 0.379 d−1 and 0.267 d−1 under green and blue filters, respectively. Both strains produced high lipid yields under the blue coloured filter, with the native and imported Chlorella strains managing lipid yields of 41.87% dry cell weight (dcw) and 32.29% dcw, respectively. The native Chlorella strain also significantly lowered (p < 0.05) the levels of total nitrogen and ammonium from wastewater with removal efficiencies of 92.17% and 44.60%, respectively, whereas the imported Chlorella strain managed a removal efficiency of 80.81% total nitrogen and 26.10% ammonium under the blue coloured filter. The results indicate that light filtration technology can be used, sustainably, in the simultaneous algaculture of native strains and remediation of wastewater

Antimicrobial effect of Brachystegia boehmii extracts and their green synthesised silver zerovalent derivatives on burn wound infectious bacteria

2026-06-10T10:16:40Z

Antimicrobial effect of Brachystegia boehmii extracts and their green synthesised silver zerovalent derivatives on burn wound infectious bacteria Sibanda, Sipho; Shoko, Ryman; Chishaya, Kudzayi; Chimwanda, Peter; Nyoni, Stephen; Ndlovu, Joice Brachystegia boehmii leaf extracts are ethnopharmacological known to treat microbial infections in burn wounds. Coupling the action of the traditional plant medicine and nanotechnology gives rise to innovative strategies for healing burn wounds. This study aimed to determine the effect of B. boehmii extracts and their green synthesised nanoparticles on bacteria which infect burn wounds. The effects of water, chloroform and methanolic leaf extracts were compared with the effects of the phytosynthesised silver nanoparticles on burn wound infectious bacteria. Dried leaves were extracted using the maceration technique, followed by filtration and concentration of the filtrate using a rotavapor. Drying was achieved by using a centrivap and appropriate masses were dissolved in dimethyl sulfoxide to achieve 100 mg/ml concentrations. Silver nanoparticles were synthesised using the methanol extract of the plant leaves and characterised using a UV–VIS spectrophotometer. The disc diffusion method was used to assess the bacterial susceptibility levels with Ciprofloxacin as the positive control and DMSO and 1mM silver nitrate as the negative controls. The green synthesised silver nanoparticles produced a yellowish colour with a peak at 420nm wavelength. They exhibited antibacterial activity against all five bacteria; Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus and Staphylococcus epidermidis comparable to those of the B. boehmii leaf solvent extracts. A zone of inhibition of 20±1.00mmwas obtained on the action of B. boehmii leaf extract against P. aeruginosa. Plant synthesized nanoparticles exhibited broad spectrum antibacterial activity and hence are potential future burn wound antibacterial therapeutics

Advances in schistosomiasis drug discovery based on natural products.

2026-06-10T10:04:03Z

Advances in schistosomiasis drug discovery based on natural products. Mtemelia, F. L.; Ndlovu, J.; Mugumbate, G.; Makwikwi, T.; Shoko, R. Schistosomiasis is a neglected tropical disease affecting over 250 million people worldwide. The disease is the second most prevalent neglected tropical disease after malaria. Treatment of schistosomiasis relies on the administration of praziquantel (also known as biltricide). Reliance on a single drug poses a threat to the public health system as the parasite may become resistant as shown by some laboratory findings. The possibility of the resistance rising to clinically significant levels has motivated the scientific community to search for new drug nominees. For a long time, natural products have always been a foundation for the identification of drug leads in the pharmaceutical industry. This paper reviews the progress made in the discovery of natural anti-schistosomal agents in the field of drug discovery. We focus mainly on natural products that have been tested on the schistosome parasite and exhibited potency. We also highlight applications of advanced techniques in drug discovery, with a major focus on computer-aided drug discovery methods. Specifically, we discuss structure-based drug discovery and ligand-based drug design approaches, with an emphasis on virtual screening.

An assessment of themolluscicidal potential of Cucurbita maxima seed extracts on Biomphalaria pfeifferi and Bulinus globosus snails

2026-05-22T10:24:03Z

An assessment of themolluscicidal potential of Cucurbita maxima seed extracts on Biomphalaria pfeifferi and Bulinus globosus snails Mtemeli, Floryn L.; Walter, Irene; Tinago, Tawanda; Shoko, Ryman Reports of snails’ resistance to niclosamide appeared recently and finding new molluscicides becomes necessary. We investigated the molluscicidal effects of Cucurbita maxima seed extracts on Biomphalaria pfeifferi, and Bulinus globosus snails under laboratory conditions. For B. pfeifferi, we tested seed extracts on juvenile and adult snails while only adult B. globosus were available for testing. Snails were exposed to water and crude ethanol extracts for 72 h and significant concentrationdependent mortality rates were observed. The number of B. pfeifferi juveniles collected was not enough for a comprehensive investigation against both solvents. We, therefore, tested them against water extracts only. A lethal concentration of 0.02 mg/mL killed 50% of the snails (LC50) for both water and ethanol extracts on adult B. pfeifferi snails. Our results suggest that pumpkin seed extracts have a significant molluscicidal effect on B. pfeifferi and B. globosus snails. The LC50 values for all the extracts in B. pfeifferi and B. globosus snails are within the threshold set for potential molluscicides by the World Health Organisation. We propose that C.maxima seed extracts be considered as potential molluscicidal agents in Schistosomiasis transmission control.