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In this work, bioleaching and dissolution processes of chalcopyrite from three different regions were investigated and compared mainly by leaching experiments, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical analysis. Hall effect experiments showed that one (chalcopyrite A) belonged to p-type chalcopyrite whose carrier concentrations were high, while the other two (chalcopyrite B and C) were both n-type chalcopyrite whose carrier concentrations were low. A remarkably higher copper extraction of p-type chalcopyrite could be achieved during bioleaching by L. ferriphilum compared with n-type chalcopyrite. Redox potential in bioleaching of p-type chalcopyrite can be maintained at the appropriate range (about 380–480 mV vs. Ag/AgCl) for a longer period of time. Acid consumption in bioleaching of p-type chalcopyrite was significantly lower than that of n-type chalcopyrite. SEM analysis indicated that p-type chalcopyrite was more easily corroded by microorganism than n-type chalcopyrite. XPS analysis revealed that monosulfide (S2−), disulfide (S22−), polysulfide (Sn2−) and sulfate (SO42−) were the main intermediate species during bioleaching of both p-type and n-type chalcopyrite. Electrochemical analysis showed that the electrochemical dissolution processes of p-type and n-type chalcopyrite were similar, while the conductivity and oxidation-reduction rate of p-type chalcopyrite was significantly higher than those of n-type chalcopyrite, thus resulting in significant higher electrochemical dissolution kinetics and copper extraction. This work is potentially useful in explaining the inconsistences in chalcopyrite hydrometallurgy.

Introduction Susceptibility to lipid metabolic dysfunction are more frequent in individuals with dampness-heat (DH) constitution, which might be caused by the changes in the gut microbiome. This study is to explore the structural and functional characteristics of the fecal-associated microbiome (FAM) in DH constitution and screen FAM-related biomarkers of DH constitution. Methods Fecal samples were collected. The FAM structure was described with alpha/beta diversity indexes and relative abundances of dominant taxa; the distribution/functional differences of the FAM between DH and balanced constitutions were analyzed by Wilcoxon rank-sum test, MetagenomeSeq and LEfSe analysis, and the specific OTUs were screened to construct ROC curve. Results There was a significant difference between the groups in the sweet preference, ACE and Chao1 indexes. In PCoA and PLS-DA, the bacterial communities in the balanced samples and DH samples clustered separately. Notably, there were 115 differentially distributed OTUs between groups identified in the MetagenomeSeq analysis and 213 OTUs identified with the Wilcoxon rank-sum test. Predicted functions showed that 12 metabolic pathways were differentially distributed between groups, including the pathway related to glycerolipid metabolism. The AUC of ROC curve based on the 4 screened specific OTUs was 0.91, and the relative abundance of these 4 OTUs could result in changes in lipid metabolism. Conclusion Unique FAM structural characteristics were identified in DH constitution, which might involve in changes in lipid metabolism and susceptibility to lipid metabolic dysfunction. The 4 screened specific OTUs could be used as potential biomarkers of DH constitution to assist clinical diagnosis.