Secondary plant metabolites remain one of the key sources of therapeutic agents despite the development of new approaches for the discovery of medicinal drugs. In the current study, chemical analysis, and biological activities of Kei apple (Dovyalis caffra) methanolic extract were evaluated. Chemical analysis was performed using HPLC and GC–MS. Antiviral and anticancer effect were assessed using the crystal violet technique and activity against human liver cells (HepG2), respectively. Antibacterial activity was tested with the disc diffusion method. The obtained results showed that chlorogenic acid (2107.96 ± 0.07 µg/g), catechin (168 ± 0.58 µg/g), and gallic acid (15.66 ± 0.02 µg/g) were the main bioactive compounds identified by HPLC techniques. While, compounds containing furan moieties, as well as levoglucosenone, isochiapin B, dotriacontane, 7-nonynoic acid and tert-hexadecanethiol, with different biological activities were identified by GC–MS. Additionally, inhibition of 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) scavenging was 79.25% at 2000 µg/mL, indicating its antioxidant activity with IC₅₀ of 728.20 ± 1.04 µg/mL. The tested extract exhibited potential anticancer activity (58.90% toxicity) against HepG2 cells at 1000 µg/mL. Potential bacterial inhibition was observed mainly against Escherichia coli and Proteus vulgaris, followed by Staphylococcus aureus and Bacillus subtilis with a diameter of growth inhibition ranging from 13 to 24 mm. While weak activities were recorded for fungi Candida albicans (10 mm). The extract showed mild antiviral activity against human coronavirus 229E with a selective index (SI) of 10.4, but not against human H3N2 (SI of 0.67). The molecular docking study's energy ratings were in good promise with the experiment documents of antibacterial and antiviral activities. The findings suggest that D. caffra juice extract is a potential candidate for further experiments to assess its use as potential alternative therapeutic agent.

White-rot fungi are vital microorganisms that can decay lignocellulosic biomass. This study investigated the ability of white-rot fungus found on rotten wood to produce ligninolytic enzymes and their enhancement using nanoparticles (NPs). Phanerochaete chrysosporium was isolated from decayed wood. Its ability to produce ligninolytic enzymes, namely CMCase, FPase, Laccase, and MnPase, was recorded. The enzymes’ productivity was enhanced via utilization of the surfactant polysorbate 80 with optimum concentration 0.20 mL/L for maximum CMCase (201.33 ± 2.31 U/mL) and FPase (66.33 ± 0.58 U/mL), whereas the corresponding value was 0.15 mL/L for laccase and MnPase production. Mn2O3NPs and CuONPs enhanced the enzymes’ productivity but with different levels according to their concentrations, where the maximum productivity of CMCase (220.67 ± 2.31 U/mL) and (FPase 74.63 ± 3.51 U/mL) were at 50 ppm, but MnPase (0.52 ± 0.01 U/mL) and laccase (2.88 ± 0.01U/mL) were at 25 ppm and 75 ppm of CuONPs, respectively. Mn2O3NPs at 75 ppm enhanced the productivity of CMCase (219.33 ± 1.15 U/mL) and FPase (74.63 ± 3.51U/mL); but at 25 ppm and 75 ppm enhanced the productivity of laccase (2.40 ± 0.04U/mL) and MnPase (0.73 ± 0.03 U/mL), respectively. Thus, NPs were found to play a vital role in improving the productivity of ligninolytic enzymes.