RESUMO
Dry mature pericarp of Citrus reticulata "Chachi" (PCR), Pericarpium Citri Reticulatae Chachiensis, is a traditional Chinese medicine that displays characteristics of different usage at different harvest times in clinical use. The corresponding changes in the bioactive components in PCR from different harvest times remain unclear. Therefore, in this study, broadly targeted metabolomics technology was used to compare the differences in bioactive components among pericarps of PCR, which are the raw material of PCR at different growth stages. In the results, 210 kinds of flavonoid metabolites were detected. The content of hesperidin in red PCR harvested in December was higher than that in Citri Reticulatae Pericarpium Viride (CRPV) and reddish PCR harvested from July to November. Furthermore, the content of nobiletin, tangeretin, and 3,3',4',5,6,7,8-heptamethoxyflavone in CRPV from July to September was higher than that in the PCR harvested at other times. In addition, the result of cluster analysis and PCA showed that CRPV harvested from July to September had an obvious grouping pattern with the reddish PCR and the red PCR harvested from October to December. Differential metabolites in six comparison groups (A1 vs. A6, A1 vs. A2, A2 vs. A3, A3 vs. A4, A4 vs. A5, A5 vs. A6) were 67, 48, 14, 51, 42, and 40, respectively. The common differential metabolite of four comparison groups was 3',4',7-trihydroxyflavone (A1 vs. A2, A2 vs. A3, A3 vs. A4, A4 vs. A5). All the flavonoid differential metabolites screened were enriched in 16 metabolic pathways. Moreover, the results of the evaluation of the total antioxidant capacity indicated that CRPV in August was a suitable raw material for the production of antioxidants. Through molecular docking, the content of potential anti-SARS-CoV-2 components in the PCR in October was higher than that in the PCR in other periods. These results further proved that PCR at different harvest times was endowed with different efficacy and usage due to the difference in the accumulation of bioactive components.
RESUMO
Short chain gaseous alkanes (SCGAs) mainly consist of methane (CH4), ethane (C2H6), propane (C3H8) and butane (C4H10). The first three SCGAs have been shown to remove perchlorate (ClO4-) and selenate (SeO42-), yet it is unknown whether C4H10 is available to reduce these contaminants. This study demonstrated that C4H10 fed biofilms were capable of reducing ClO4- and SeO42- to chloride (Cl-) and elemental selenium (Se0), respectively, by employing two independent membrane biofilms reactors (MBfRs). Batch tests showed that C4H10 and oxygen fed biofilms had much higher ClO4- and SeO42- reduction rates and enhanced expression levels of bmoX and pcrA than that without C4H10 or O2. Polyhydroxyalkanoates (PHA) accumulated in the biofilms when C4H10 was supplied, and they decomposed for driving ClO4- and SeO42- reduction when C4H10 was absent. Moreover, we revisited the literature and found that a cross-feeding pathway seems to be universal in microaerobic SCGA-driven perchlorate and selenate reduction processes. In the ClO4--reducing MBfRs, Mycobacterium primarily conducts C2H6 and C3H8 oxidation in synergy with Dechloromonas who performs perchlorate reduction, while both Mycobacterium and Rhodococcus carried out C4H10 oxidation with perchlorate-respiring Azospira as the partner. In the SeO42--reducing MBfRs, Mycobacterium oxidized C2H6 solely or oxidized C3H8 jointly with Rhodococcus, while Burkholderiaceae likely acted as the selenate-reducing bacterium. When C4H10 was supplied as the electron donor, both Mycobacterium and Rhodococcus conducted C4H10 oxidation in synergy with unknow selenate-reducing bacterium. Collectively, we confirm that from CH4 to C4H10, all SCGAs could be utilized as electron donors for bio-reduction process. These findings offer insights into SCGA-driven bio-reduction processes, and are helpful in establishing SCGA-based technologies for groundwater remediation.