Establishment of callus derived from Jatropha curcas L. petiole explants and phytochemical screening

Abstract Aims: The focus of this study was to assess the production of secondary metabolites of callus derived from Jatropha curcas L. petiole explants. Results: Excellent growth of callus was obtained. Callus was soft, friable, lush green in color and grew fast from 8 to 30 days of culture then stabilized at low growth rate. The results obtained by phyto-chemical tests revealed the presence of saponins, tannins, alkaloids, steroids and flavonoids. The tannin contents in vitro proliferated callus, leaves, stem barks, root barks, roots and latex of J. curcas were found to be 161, 173, 220, 214, 43 and 245 μg tannic acid equivalent/g of dry weight respectively. Conclusion: The results of this study have revealed that in vitro induced callus from J. curcas petiole explants was able to produce secondary metabolites. The pharmacological activity of J.curcas reported by various researchers can be attributed to the presence of these phytochemicals

Mineralogical variations with the mining depth in the Congo Copperbelt: technical and environmental challenges in the hydrometallurgical processing of copper and cobalt ores

For a long time in the Democratic Republic of Congo, the mining of ores for the production of copper cathodes and salts of cobalt was mostly conducted in the near-surface oxidized mineralization of the Congo Copperbelt. An important part of this mineralization is found in geological settings where copper and cobalt mainly exist as mixtures of oxides and sulfides. With the depletion of surface-rich minerals, mining is taking place at depths where sulfide minerals are prevalent. Using current technologies, the hydrometallurgical processing of ores with high levels of sulfide minerals results in poor metal recovery due to their retention in process wastes. These mineral wastes have the propensity to lead to Acid Mine Drainage (AMD) when exposed to rainfall and atmospheric air. Therefore, major changes in the technologies implemented will be needed in order to guarantee higher process efficiencies while endeavoring to uphold environment safeguarding reinforcement. This work aimed to demonstrate the urgency of updating the hydrometallurgical technologies implemented for the processing of copper-cobalt ores with an emphasis put on minimizing the environmental footprint of process wastes. Four copper-cobalt deposits and downstream hydrometallurgical processes were surveyed to get a better understanding of how changes in mineralization occurring in the deposits will influence the processing technologies and practices during the management of process wastes