In this study, heavy metal and microbial safety assessment of raw and cooked pumpkin and Amaranthus viridis leaves grown in Abakaliki, Nigeria, was examined. The levels of lead (Pb), arsenic (As), chromium (Cr), cadmium (Cd), and mercury (Hg) were evaluated using atomic absorption spectrophotometer. The microbial cells were counted and further identified to species level using 16S rDNA and ITS rDNA sequencing analysis at CABI microbial identification services United Kingdom (UK). The results showed that the heavy metal concentrations of lead (10.5, 12.0), arsenic (7.5, 8.5), chromium (0.9, 0.1), and mercury (13.1, 14.0) in the pumpkin and A. viridis leaves, respectively, were above maximum acceptable limit according to relevant national and international food regulatory agencies (Tables and ). Cooking significantlyreduced the concentrations of the heavy metals at (p > 0.05) to or below, lead (6.8, 8.4), arsenic (5.1, 6.1), chromium (0.6.0.1), and mercury (9.5, 11.4) in the pumpkin and A. viridis leaves, respectively, but still not to international safe limit. The result of the microbial safety assessment showed that the microbial load of both the pumpkin and Amaranthus viridis leaves were above acceptable limit and the contaminating organisms were identified as Escherichia coli (504743), Klebsiella pneumonia (504744b), and Aspergillus flavus (504740).This study therefore shows that the vegetables (pumpkin and A. viridis leaves) contain unacceptable levels of toxic heavy metals and potentially dangerous pathogenic microorganisms, thus present significant health risk for the consumers.

Plant-derived oleanolic and ursolic acids are sought-after triterpenoid sapogenins used in modern curative and preventive medicines. Several plant species have been overexploited for triterpenoid sapogenin extraction. In this study, we reconfigured the metabolic fingerprints of Ganoderma lucidum and produced oleanolic and ursolic acids, ganoderic acids, and meroterpenoids. Oleanolic and ursolic acids were first synthesized in the medicinal mushroom by expressing amyrin-synthases and beta-amyrin 28-monooxygenase from plants. The production of sapogenin precursors (2,3-oxidosqualene) and ganoderic acid was enhanced by reconstructing the mushroom terpenoid biosynthetic pathway using a new terpenoid gene cluster recovered from the mycelium. Overexpression of the VeA–VelB velvet and LaeA proteins upregulated secondary metabolism and stimulated the hyperproduction of a renoprotective meroterpenoid. The VeA–VelB velvet and LaeA protein variants developed a radically distinctive yellow phenotype that has not yet been reported in any of the mushroom mycelial variants. CRISPR-AsCpf1-based lanosterol synthase editing repressed the competing ganoderic acid pathway and further enhanced 2,3-oxidosqualene accumulation and triterpenoid sapogenin biosynthesis. The oleanolic and ursolic acid titer reached 1.478 g L⁻¹ and 0.87 g L⁻¹, respectively, when the fermentation conditions were optimized in a 5 L lab bioreactor. This study presents fascinating metabolic engineering strategies that remodel Ganoderma's metabolic route and produce oleanolic acid, ursolic acid, ganoderic acids, and meroterpenoids. These new strains could replace wild plant species as a green source of triterpenoid sapogenins.