A screening method using 15% CO
2
(v/v) as screening stress and a spotting plate method was developed to isolate microalgae with the potential to convert flue gas CO
2
to biomass. A total of six ...microalgal strains, belonging to the genera
Chlorella
,
Heynigia
,
Desmodesmus
, and
Scenedesmus
, were isolated from ponds near metallurgical/cement/power plants. The growth of these isolated strains was dramatically promoted at 5 to 15% CO
2
when they were cultivated in bubble column photobioreactors aerating with 0.03%, 5%, 10%, and 15% CO
2
. The growth of
Heynigia riparia
SX01 in particular showed substantial improvement with the increase of CO
2
concentrations from 5 to 15%. Furthermore, the maximum biomass, overall biomass productivity, maximum biomass productivity, and maximum CO
2
fixation rate of these microalgal strains greatly increased at 5 to 15% CO
2
as well.
Chlorella sorokiniana
GS03 showed the highest values in maximum biomass productivity (0.36 g L
−1
day
−1
) and maximum CO
2
fixation rate (0.66 g L
−1
day
−1
) at 5% CO
2
.
Heynigia riparia
SX01 exhibited the highest values of maximum biomass (3.28 g L
−1
), overall biomass productivity (0.27 g L
−1
day
−1
), maximum biomass productivity (0.39 g L
−1
day
−1
), and maximum CO
2
fixation rate (0.71 g L
−1
day
−1
) at 15% CO
2
. This study provides not only an efficient screening method obtaining microalgae with wide CO
2
tolerance but also microalgal strains utilizing high levels of CO
2
up to 15% to produce biomass, which contributes to further exploration in converting real flue gas CO
2
into biomass feedstock.
Statins, a class of drugs that can effectively remove cholesterol from serum, are used to regulate plasma total cholesterol and reduce the risk of cardiovascular diseases, but it is still unclear ...whether the drug are modulated by gut microbiota or the structures of gut microbiota are shaped by statins. We investigated the interactions between statins and the human gut microbiota during the in vitro fermentation process by 16S rRNA gene sequencing, gas chromatography (GC), and high-performance liquid chromatography (HPLC) analyses. The presence of fluvastatin (FLU2) specifically promoted the growth of Escherichia/Shigella, Ruminococcaceae UCG 014, and Sutterella. However, the composition of the gut bacterial microbiota remained relatively static in samples treated with rosuvastatin (ROS), simvastatin (SIM), and atorvastatin (ATO). The PICRUSt program predicted moderate differences in the functional categories related to the biosynthesis of other secondary metabolites, cellular processes and signaling, and signal transduction in the FLU2 fermentation samples. Our study revealed substantial variation in the structure and function of microbiomes from the FLU2-treated samples. In addition, short-chain fatty acids (SCFAs) were also significantly decreased in FLU2-treated samples compared with the samples treated with other stains. Statins can be degraded by the human gut microbiota in vitro, and the degradation rate was approximately 7%-30% and 19%-48% after fermentation was allowed to proceed for 24 h and 48 h, respectively. Generally, FLU2 could largely shape the composition and function of human gut microbiota, which resulted in changes in the production of SCFAs. In turn, all statins could be degraded or modified by the gut microbiota. Our study paves the way for elucidating statin-gut microbiota interactions in vitro towards the improvement of the host health and personalized medicine.
Nannochloropsis oculata
CCMP 525,
Dunaliella salina
FACHB 435, and
Chlorella sorokiniana
CCTCC M209220 were compared in mixotrophic and photoautotrophic cultures in terms of growth rate, protein, and ...lipid content. Growth improved in glucose, and the biomass productivities of
N. oculata
,
D. salina
, and
C. sorokiniana
were found to be 1.4-, 2.2- and 4.2-fold that observed photoautotrophically. However, biomass and lipid production decreased at the highest glucose concentrations. Meanwhile, the content of protein and lipid were significantly augmented for mixotrophic conditions at least for some species.
C. sorokiniana
was found to be well suited for lipid production based on its high biomass production rate and lipid content reaching 51% during mixotrophy. Expression levels of
acc
D (heteromeric acetyl-CoA carboxylase beta subunit),
acc
1 (homomeric acetyl-CoA carboxylase),
rbc
L (ribulose 1, 5-bisphosphate carboxylase/oxygenase large subunit) genes in
C. sorokiniana
were studied by real-time PCR. Increased expression levels of
acc
D reflect the increased lipid content in stationary phase of mixotrophic growth, but expression of the
acc
1 gene remains low, suggesting that this gene may not be critical to lipid accumulation. Additionally, reduction of expression of the
rbc
L gene during mixotrophy indicated that utilization of glucose was found to reduce the role of this gene and photosynthesis.
To explore the potential mechanism of Shenkang injection (SKI) in the treatment of chronic renal failure based on network pharmacology and molecular docking technology, and to verify the core targets ...and key pathways by using the renal failure model. The active components and targets of Shenkang injection were retrieved by TCMSP database, and the disease related targets were obtained by OMIM, GeneCards and other databases. Then, the intersection was obtained, and were imported into String database for PPI analysis. After further screening of core targets, GO and KEGG analysis were performed. Autodock software was used to predict the molecular docking and binding ability of the selected active ingredients and core targets. Chronic renal failure (CRF) model was established by adenine induction in rats, and the pathological observation of renal tissues was conducted. Meanwhile, the effects of Shenkang injection and its active components on core targets and pathways of renal tissues were verified. The results of network pharmacology showed that the main components of Shenkang injection might be hydroxysafflor yellow A (HSYA), tanshinol, rheum emodin, Astragaloside IV. Through enrichment analysis of core targets, it was found that Shenkang injection may play an anti-chronic renal failure effect through PI3K-Akt signaling pathway. Molecular docking results showed that the above pharmacodynamic components had strong binding ability with the target proteins PI3K and Akt. The results of animal experiments showed that renal function indexes of Shenkang injection group and pharmacodynamic component group were significantly improved compared with model group. HE staining results showed that the pathological status of the kidney was significantly improved in SKI and pharmacodynamic component treatment groups. Immunohistochemical results showed that the renal fibrosis status was significantly reduced in SKI and pharmacodynamic component treatment groups. q-RTPCR and WB results showed that the expression levels of PI3K and Akt were significantly decreased in the treatment groups (P< 0.05). Shenkang injection may inhibit PI3K-Akt signaling pathway to play an anti-chronic renal failure role through the pharmacodynamic component hydroxysafflor yellow A (HSYA), tanshinol, rheum emodin, Astragaloside IV.
Clay minerals associated with microbial body and trace fossils in rocks deposited in shallow marine environments have importance in understanding microbial preservation. We show experimentally that ...the presence of suspended detrital clays in oceanic environments is a crucial control on the formation of co-aggregates between filamentous cyanobacteria and clay minerals and is thus important in the sedimentation and subsequent preservation of cyanobacteria. Strong cyanobacteria-clay co-aggregation occurs over short time periods (3–7 days) in the presence of 10 mg/L of suspended clay minerals (illite, kaolinite and montmorillonite), and the occurrence of co-aggregation is not affected by the type of clay minerals present. The cyanobacteria-clay co-aggregation shows a pronounced effect on preserving the biomass of cyanobacteria. The surface properties of clay minerals and cyanobacteria, specifically the electrostatic attraction between the oppositely charged surfaces of cyanobacteria and clay minerals, are the main drivers of cyanobacteria-clay co-aggregation. Chemical effects, such as the deprotonation of COOH groups in active organic compounds secreted by cyanobacteria and therefore the release of H+, result in local dissolution of clay and slight structure changes in the bulk of clay minerals. Compared with the suspended clay, dissolved ions (Si, Al or Fe ions) are of secondary importance in the formation of cyanobacteria-clay co-aggregates, although these ions further promote this process. Overall, the cyanobacteria-clay co-aggregation not only substantially affects the preservation of cyanobacteria, but also may have potentially important and profound impacts on related geochemical processes such as microbial dissolution of clay minerals and the biogeochemical Si cycle in marine environments.
To reveal the mechanism of Shenkang injection (SKI) in the treatment of chronic renal failure, and verify the key pathway. In this work, an untargeted metabolomics approach was performed by LC-MS ...coupled with multivariate statistical analysis to provide new insights into therapeutic mechanism of SKI. Hematoxylin–eosin (H&E) Staining and Immunohistochemistry were used to evaluate the effects of drug treatment, Western blot was used to verify the critical pathway. Then, a total of 44 potential biomarkers of chronic renal failure (CRF) were identified and reversed regulation, including 2,8-dihydroxypurine, 5-methoxytryptophan, uric acid, acetylcarnitine, taurine, etc. Mainly concerned with arginine and proline metabolism, purine metabolism, histidine metabolism, etc. Pathological examination showed that the renal interstitium of SKI group was significantly improved, with fewer inflammatory cells and thinner vascular walls compared with the model group. Immunohistochemical results showed that the expression of α-smooth muscle actin (α-SMA) was decreased, and the expression of E-cadherin was increased in CRF model group, and the two indicators were reversed regulation in SKI injection, indicating that the degree of fibrosis was relieved. Critical signaling pathway phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) and nuclear factor-kappaB (NF-κB) protein expressions were significantly inhibited. This study was the first to employ metabolomics to elucidate the underlying mechanisms of SKI in chronic renal failure. The results would provide some support for clinical application of traditional Chinese medicines in clinic.
Abiotic iron monosulfide (FeS) has attracted growing interests in dechlorinating trichloroethylene (TCE) in anoxic groundwater, but it is still unclear how biogenic FeS affects the dechlorination and ...thus the cytotoxity of TCE. In this work, a biogenic FeS was synthesized by
Shewanella oneidensis
MR-1 with addition of ferrihydrite and S
0
, and it was used for dechlorination of TCE in alkaline environment and the de-cytotoxicity was evaluated by the growth of
Synechocystis
sp. PCC6803. The results show that the biogenic FeS was of mackinawite, with a loose flower-like mosaic structure. The dechlorination of TCE by the biogenic FeS was accelerated by 6 times than that by abiotic FeS. TCE was dechlorinated mainly by hydrogenolysis to form dichloroethane (C
2
H
2
Cl
2
), vinyl chloride (C
2
H
3
Cl), and finally ethylene, accompanied with transformation of both Fe
2+
to Fe
3+
and monosulfide to disulfide and polysulfide on the biogenic FeS surface. The concentration for 50% of maximal inhibition effect (EC
50
) of TCE to
Synechocystis
was 486 mg/L and the inhibition to
Synechocystis
under the EC
50
was relieved more significantly on addition of the biogenic FeS than that of abiotic FeS. These results indicate that the biogenic FeS promoted the dechlorination and thus de-cytotoxity of TCE.
Graphic abstract
The biosilicification of diatoms allows for the customization of the synthesis of functionalized diatom frustules. The S active sites (–SH) on diatom frustules were created by adding the organic ...silicon sources tetramethoxysilane (TMOS) and (3-mercaptopropyl)trimethoxysilane (MPTMS). The mechanisms of adsorption-reduction and the indirect effects of S active sites on electrochemical performance were declared. The DBS@C-Ag-3 anode material sourced from the cultivation condition with a silicon source of TMOS:MPTMS = 3:1 shows the best comprehensive performance and delivers a discharge capacity of ∼660 mAh·g−1 after 1000 cycles at 1 A·g−1. The electrochemical performance of DBS@C-Ag anode materials is also found to be dominated by structure at high temperatures and conductivity at low temperatures. Such a diatom frustule structure with sulfhydryl functionalization is promising for anode materials, and it suggests a biological strategy for creating other electrode materials by modifying them with metals to improve electrochemical performances.
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•-SH active sites on diatom frustules were created by adding organic silicon sources•Thiol-functionalized diatoms plus Ag modification are used as anode material sources•DBS@C-Ag-3 anodes delivered ∼660 mAh·g−1 after 1000 cycles at 1 A·g−1•Dominant role of structure and conductivity at different temperatures was revealed
Electrochemistry; Materials science; Materials chemistry
Bioleaching processes or microbially mediated iron/sulfur redox processes in acid mine drainage (AMD) result in mineral dissolution and transformation, the release of mercury and other heavy metal ...ions, and changes in the occurrence forms and concentration of mercury. However, pertinent studies on these processes are scarce. Therefore, in this work, the Fe/S redox-coupled mercury transformation mediated by
ATCC 23270 under aerobic and/or anaerobic conditions was studied by combining analyses of solution behavior (pH, redox potential, and Fe/S/Hg ion concentrations), the surface morphology and elemental composition of the solid substrate residue, the Fe/S/Hg speciation transformation, and bacterial transcriptomics. It was found that: (1) the presence of Hg
significantly inhibited the apparent iron/sulfur redox process; (2) the addition of Hg
caused a significant change in the composition of bacterial surface compounds and elements such as C, N, S, and Fe; (3) Hg mainly occurred in the form of Hg
, HgS, and HgSO
in the solid substrate residues; and (4) the expression of mercury-resistant genes was higher in earlier stages of growth than in the later stages of growth. The results indicate that the addition of Hg
significantly affected the iron/sulfur redox process mediated by
ATCC 23270 under aerobic, anaerobic, and coupled aerobic-anaerobic conditions, which further promoted Hg transformation. This work is of great significance for the treatment and remediation of mercury pollution in heavy metal-polluted areas.
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