Continuous Covalent Organic Framework Membranes with Ordered Nanochannels as Tunable Transport Layers for Fast Butanol/Water Separation.

Polymeric membranes with high permselective performance are desirable for energy-saving bioalcohol separations. However, it remains challenging to design membrane microstructures with low-resistance channels and a thin thickness for fast alcohol transport. Herein, we demonstrate highly crystalline covalent organic framework (COF) membranes with ordered nanochannels as tunable transport layers for efficient butanol/water separation. The thickness was well-regulated by altering the concentration and molar ratio of two aldehyde monomers with different reactivity. The surface-integrated poly(dimethylsiloxane) produced defect-free and hydrophobic COF membranes. The membrane with continuous transport channels exhibited an exceptional flux of up to 18.8 kg m-2 h-1 and a pervaporation separation index of 217.7 kg m-2 h-1 for separating 5 wt % n-butanol/water. The separation efficiency exceeded that of analogous membranes. The calculated mass-transfer coefficient of butanol followed an inverse relationship with the COF membrane thickness. Consequently, this work reveals the great potential of crystalline polymeric membranes with high-density nanopores for biofuel recovery.

Structural and Biochemical Analysis of Butanol Dehydrogenase From Thermotoga maritima.

Butanol dehydrogenase (BDH) plays a crucial role in butanol biosynthesis by catalyzing the conversion of butanal to butanol using the coenzyme NAD(P)H. In this study, we observed that BDH from Thermotoga maritima (TmBDH) exhibits dual coenzyme specificity and catalytic activity with NADPH as the coenzyme under highly alkaline conditions. Additionally, a thermal stability analysis on TmBDH demonstrated its excellent activity retention even at elevated temperatures of 80°C. These findings demonstrate the superior thermal stability of TmBDH and suggest that it is a promising candidate for large-scale industrial butanol production. Furthermore, we discovered that TmBDH effectively catalyzes the conversion of aldehydes to alcohols and exhibits a wide range of substrate specificities toward aldehydes, while excluding alcohols. The dimeric state of TmBDH was observed using rapid online buffer exchange native mass spectrometry. Additionally, we analyzed the coenzyme-binding sites and inferred the possible locations of the substrate-binding sites. These results provide insights that improve our understanding of BDHs.

1-Butanol treatment enhances drought stress tolerance in Arabidopsis thaliana.

Abiotic stress is a major factor affecting crop productivity. Chemical priming is a promising strategy to enhance tolerance to abiotic stress. In this study, we evaluated the use of 1-butanol as an effectual strategy to enhance drought stress tolerance in Arabidopsis thaliana. We first demonstrated that, among isopropanol, methanol, 1-butanol, and 2-butanol, pretreatment with 1-butanol was the most effective for enhancing drought tolerance. We tested the plants with a range of 1-butanol concentrations (0, 10, 20, 30, 40, and 50 mM) and further determined that 20 mM was the optimal concentration of 1-butanol that enhanced drought tolerance without compromising plant growth. Physiological tests showed that the enhancement of drought tolerance by 1-butanol pretreatment was associated with its stimulation of stomatal closure and improvement of leaf water retention. RNA-sequencing analysis revealed the differentially expressed genes (DEGs) between water- and 1-butanol-pretreated plants. The DEGs included genes involved in oxidative stress response processes. The DEGs identified here partially overlapped with those of ethanol-treated plants. Taken together, the results show that 1-butanol is a novel chemical priming agent that effectively enhances drought stress tolerance in Arabidopsis plants, and provide insights into the molecular mechanisms of alcohol-mediated abiotic stress tolerance.

Transcriptomic characterization of recombinant Clostridium beijerinckii NCIMB 8052 expressing methylglyoxal synthase and glyoxal reductase from Clostridium pasteurianum ATCC 6013.

Bioconversion of abundant lactose-replete whey permeate to value-added chemicals holds promise for valorization of this expanding food processing waste. Efficient conversion of whey permeate-borne lactose requires adroit microbial engineering to direct carbon to the desired chemical. An engineered strain of Clostridium beijerinckii NCIMB 8052 (C. beijerinckii_mgsA+mgR) that produces 87% more butanol on lactose than the control strain was assessed for global transcriptomic changes. The results revealed broadly contrasting gene expression patterns in C. beijerinckii_mgsA+mgR relative to the control strain. These were characterized by widespread decreases in the abundance of mRNAs of Fe-S proteins in C. beijerinckii_mgsA+mgR, coupled with increased differential expression of lactose uptake and catabolic genes, iron uptake genes, two-component signal transduction and motility genes, and genes involved in the biosynthesis of vitamins B5 and B12, aromatic amino acids (particularly tryptophan), arginine, and pyrimidines. Conversely, the mRNA patterns suggest that the L-aspartate-dependent de novo biosynthesis of NAD as well as biosynthesis of lysine and asparagine and metabolism of glycine and threonine were likely down-regulated. Furthermore, genes involved in cysteine and methionine biosynthesis and metabolism, including cysteine desulfurase-a central player in Fe-S cluster biosynthesis-equally showed reductions in mRNA abundance. Genes involved in biosynthesis of capsular polysaccharides and stress response also showed reduced mRNA abundance in C. beijerinckii_mgsA+mgR. The results suggest that remodeling of cellular and metabolic networks in C. beijerinckii_mgsA+mgR to counter anticipated effects of methylglyoxal production from heterologous expression of methylglyoxal synthase led to enhanced growth and butanol production in C. beijerinckii_mgsA+mgR. IMPORTANCE: Biological production of commodity chemicals from abundant waste streams such as whey permeate represents an opportunity for decarbonizing chemical production. Whey permeate remains a vastly underutilized feedstock for bioproduction purposes. Thus, enhanced understanding of the cellular and metabolic repertoires of lactose-mediated production of chemicals such as butanol promises to identify new targets that can be fine tuned in recombinant and native microbial strains to engender stronger coupling of whey permeate-borne lactose to value-added chemicals. Our results highlight new genetic targets for future engineering of C. beijerinckii for improved butanol production on lactose and ultimately in whey permeate.

Ag modified ZnO nanoflower gas sensitive sensor for selective detection of n-butanol.

Ag modified ZnO nanoflowers were successfully prepared by sunlight induced solvent reduction method. The samples were characterized by x-ray diffractometer, field emission scanning electron microscope, transmission electron microscope and energy dispersive x-ray spectrum, and the results confirmed the presence of Ag nanoparticles on the ZnO nanoflower. The gas sensing performance of the materials was studied at different operating temperatures and different n-butanol concentrations. The results showed that the Ag modified ZnO nanoflower sensor responded to 50 ppm n-butanol up to 147.17 at 280 °C, and the Ag modified ZnO nanoflower sensor exhibited excellent repeatability, stability and response recovery time. In addition, different target gases were employed for the selectivity study of the Ag modified ZnO nanoflower. It can be found that the Ag modified ZnO nanoflower had good selectivity for n-butanol. The improved response of the Ag modified ZnO nanoflower sensor was attributed to the catalytic effect of Ag nanoparticles. The results indicate that the Ag modified ZnO nanoflower will become a very promising sensing material for n-butanol gas detection.

New insights into the influence of pre-culture on robust solvent production of C. acetobutylicum.

Clostridia are known for their solvent production, especially the production of butanol. Concerning the projected depletion of fossil fuels, this is of great interest. The cultivation of clostridia is known to be challenging, and it is difficult to achieve reproducible results and robust processes. However, existing publications usually concentrate on the cultivation conditions of the main culture. In this paper, the influence of cryo-conservation and pre-culture on growth and solvent production in the resulting main cultivation are examined. A protocol was developed that leads to reproducible cultivations of Clostridium acetobutylicum. Detailed investigation of the cell conservation in cryo-cultures ensured reliable cell growth in the pre-culture. Moreover, a reason for the acid crash in the main culture was found, based on the cultivation conditions of the pre-culture. The critical parameter to avoid the acid crash and accomplish the shift to the solventogenesis of clostridia is the metabolic phase in which the cells of the pre-culture were at the time of inoculation of the main culture; this depends on the cultivation time of the pre-culture. Using cells from the exponential growth phase to inoculate the main culture leads to an acid crash. To achieve the solventogenic phase with butanol production, the inoculum should consist of older cells which are in the stationary growth phase. Considering these parameters, which affect the entire cultivation process, reproducible results and reliable solvent production are ensured. KEY POINTS: • Both cryo- and pre-culture strongly impact the cultivation of C. acetobutylicum • Cultivation conditions of the pre-culture are a reason for the acid crash • Inoculum from cells in stationary growth phase ensures shift to solventogenesis.

Comparative analysis of a novel N-butanol-prepared antigen vs thermo-resistant and sonicated antigens for human leptospirosis detection.

The diagnosis of human leptospirosis is mainly based on serological assays. Since the extraction by N-butanol has only been studied as an antigen for the diagnosis of cattle leptospirosis, this study aimed to investigate the feasibility of the N-butanol preparation for the diagnosis of human leptospirosis and compare it with sonicated and thermo-resistant antigens in IgM dot-blot test. Paired serum samples from 147 laboratory-confirmed leptospirosis cases were tested. The control group consisted of 148 serum samples from healthy individuals and nonleptospirosis cases. N-butanol antigens from serovar Copenhageni (ButC3) and serovar Patoc (ButP3) showed reactivity with antileptospiral antibodies from patients with confirmed leptospirosis. In the acute phase, sensitivities of IgM dot-blot assay with ButC3 and ButP3 antigens were 47.6% and 51.0%, respectively. In the convalescent phase, sensitivities were 95.9% (ButC3) and 93.2% (ButP3), and no significant differences were observed among the IgM dot-blot tests with other antigens. The specificity of the IgM dot-blot test with ButC3 antigen was good (92.6%), but with ButP3 (83.1%), it was significantly lower than with the other tests. The IgM dot-blot test described in this study is simple to perform and presents reliable visual results. Antigens prepared by N-butanol proved to be valuable diagnostic markers of leptospirosis.

Revisiting the isolation and characterisation of Entamoeba histolytica lipopeptidophosphoglycan.

The parasite Entamoeba histolytica is the cause of amoebic dysentery and liver abscess in humans. On the protozoan cell surface, a variety of glycosylated molecules are involved in the interaction with the environment, such as attachment to the colonic mucus. One of these molecules is the lipopeptidophosphoglycan (LPPG), a complex surface component with antigenic properties. Its structure is only partly known, it is a glycosylphosphatidylinositol (GPI)-linked glycoprotein with a large amount of O-glycosylation. To date, the sequence of a core protein has not been identified. In this study, we further investigated this complex surface molecule aided by the availability of the monoclonal antibody EH5, which had been raised in our laboratory. We studied the extraction of LPPG in various solvent mixtures and discovered that 2-butanol saturated water was simple and superior to other solvents used in the past. The isolated LPPG was subjected to treatment with several proteases and the Ser/Thr specific cleavage agent scandium (III) trifluoromethanesulfonate (scandium triflate). The products were probed with antibody EH5 and the blots showed that the LPPG preparation was largely resistant to standard proteases, but could be cleaved by the scandium compound. These observations could point to the existence of a Ser- or Thr-rich core protein structure.

Comparative study of two indoor microbial volatile pollutants, 2-Methyl-1-butanol and 3-Methyl-1-butanol, on growth and antioxidant system of rice (Oryza sativa) seedlings.

2-Methyl-1-butanol (2MB) and 3-Methyl-1-butanol (3MB) are microbial volatile organic compounds (VOCs) and found in indoor air. Here, we applied rice as a bioindicator to investigate the effects of these indoor microbial volatile pollutants. A remarkable decrease in germination percentage, shoot and root elongation, as well as lateral root numbers were observed in 3MB. Furthermore, ROS production increased by 2MB and 3MB, suggesting that pentanol isomers could induce cytotoxicity in rice seedlings. The enhancement of peroxidase (POD) and catalase (CAT) activity provided evidence that pentanol isomers activated the enzymatic antioxidant scavenging systems, with a more significant effect observed in 3MB. Furthermore, 3MB induced higher activity levels of glutathione (GSH), oxidized glutathione (GSSG), and the GSH/GSSG ratio in rice compared to the levels induced by 2MB. Additionally, qRT-PCR analysis showed more up-regulation in the expression of glutaredoxins (GRXs), peroxiredoxins (PRXs), thioredoxins (TRXs), and glutathione S-transferases (GSTUs) genes in 3MB. Taking the impacts of pentanol isomers together, the present study suggests that 3MB exhibits more cytotoxic than 2MB, as such has critical effects on germination and the early seedling stage of rice. Our results provide molecular insights into how isomeric indoor microbial volatile pollutants affect plant growth through airborne signals.

Optimization of CO fermentation by Clostridium carboxidivorans in batch reactors: Effects of the medium composition.

OBJECTIVES: The objective of this study was to investigate the effects of medium composition on CO fermentation by Clostridium carboxidivorans. The focus was to reduce the medium cost preserving acceptable levels of solvent production. METHODS: Yeast extract (YE) concentration was set in the range of 0-3 g/L. Different reducing agents were investigated, including cysteine-HCl 0.6 g/L, pure cysteine 0.6 g/L, sodium sulphide (Na2S) 0.6 g/L, cysteine-sodium sulphide 0.6 g/L and cysteine-sodium sulphide 0.72 g/L. The concentration of the metal solution was decreased down to 25 % of the standard value. Fermentation tests were also carried out with and without tungsten or selenium. RESULTS: The results demonstrated that under optimized conditions, namely yeast extract (YE) concentration set at 1 g/L, pure cysteine as the reducing agent and trace metal concentration reduced to 75 % of the standard value, reasonable solvent production was achieved in less than 150 h. Under these operating conditions, the production levels were found to be 1.39 g/L of ethanol and 0.27 g/L of butanol. Furthermore, the study revealed that selenium was not necessary for C. carboxidivorans fermentation, whereas the presence of tungsten played a crucial role in both cell growth and solvent production. CONCLUSIONS: The optimization of the medium composition in CO fermentation by Clostridium carboxidivorans is crucial for cost-effective solvent production. Tuning the yeast extract (YE) concentration, using pure cysteine as the reducing agent and reducing trace metal concentration contribute to reasonable solvent production within a relatively short fermentation period. Tungsten is essential for cell growth and solvent production, while selenium is not required.

Evolution of the Structure and Morphology of Dual-Linker ZIF-301-eIm.

Few studies have reported on the continuous evolution of dual-linker zeolitic imidazolate frameworks' (ZIFs) structure and morphology during the crystal growth process. Herein, we report the synthesis of a novel ZIF material with CHA topology (ZIF-301-eIm) via the combination of a small-sized 2-ethylimidazole (eIm) with the large-sized 5-chlorobenzimidazole ligand. A series of derivative materials with distinct structures and morphologies were obtained via two pathways: (1) insufficient amount of eIm with prolonged crystallization time (pathway A) and (2) sufficient amount of eIm with prolonged crystallization time (pathway B). Various characterization techniques revealed the continuous evolution of structure and morphology during the crystal growth process. Insufficient amount of eIm and crystallization time (crystallization pathway A) led to ZIF-301-eIm derivatives with defective and open structures alongside an aggregated morphology of nanoparticles. Prolonging the crystallization time allowed small-sized eIm ligands to gradually fill into the framework, resulting in the formation of ZIF-301-eIm-A5 characterized by complete but dense structures with a perfect polyhedral morphology. Remarkably, a sufficient amount of eIm during synthesis (crystallization pathway B) formed ZIF-301-eIm-B1 with a similar structure and morphology to ZIF-301-eIm-A5 in just 1 day. ZIF-301-eIm-B3, with intact, dense structures, exhibits superior acetone/butanol separation performance compared to ZIF-301-eIm-A3 due to small pore windows and large cages facilitating selective adsorption of acetone through exclusion separation.

The Effect of Technological Conditions on ABE Fermentation and Butanol Production of Rye Straw and the Composition of Volatile Compounds.

The objective of this study was to evaluate the effect of pretreatment and different technological conditions on the course of ABE fermentation of rye straw (RS) and the composition of volatile compounds in the distillates obtained. The highest concentration of ABE and butanol was obtained from the fermentation of pretreated rye straw by alkaline hydrolysis followed by detoxification and enzymatic hydrolysis. After 72 h of fermentation, the maximum butanol concentration, productivity, and yield from RS were 16.11 g/L, 0.224 g/L/h, and 0.402 g/g, respectively. Three different methods to produce butanol were tested: the two-step process (SHF), the simultaneous process (SSF), and simultaneous saccharification with ABE fermentation (consolidation SHF/SSF). The SHF/SSF process observed that ABE concentration (21.28 g/L) was higher than in the SSF (20.03 g/L) and lower compared with the SHF (22.21 g/L). The effect of the detoxification process and various ABE fermentation technologies on the composition of volatile compounds formed during fermentation and distillation were analyzed.

[Mechanism of protective effect of n-butanol extract of Pulsatilla Decoction on vaginal epithelial cells under Candida albicans stimulation through EGFR/MAPK pathway based on transcriptomics].

This study aimed to investigate the protective effect and its underlying mechanism of n-butanol extract of Pulsatilla Decoction(BEPD) containing medicinal serum on vaginal epithelial cells under Candida glabrata stimulation via the epidermal growth factor receptor/mitogen activated protein kinase( EGFR/MAPK) pathway based on transcriptomics. A vulvovaginal candidiasis(VVC) mouse model was established first and transcriptome sequencing was performed for the vaginal mucosa tissues to analyze the gene expression differences among the control, VVC model, and BEPD intervention groups. Simultaneously, BEPD-containing serum and fluconazole-containing serum were prepared. A431 cells were divided into the control, model, blank serum, fluconazole-containing serum, BEPD-containing serum, EGFR agonist and EGFR inhibitor groups. Additionally, in vitro experiments were conducted using BEPD-containing serum, fluconazole-containing serum, and an EGFR agonist and inhibitor to investigate the intervention mechanisms of BEPD on C. glabrata-induced vaginal epithelial cell damage. Cell counting kit-8(CCK-8) assay was utilized to determine the safe concentrations of C. glabrata, drug-containing serum, and compounds on A431 cells. Enzyme-linked immunosorbent assay(ELISA)was employed to measure the expression levels of interleukin(IL)-1ß, IL-6, granulocyte-macrophage colony-stimulating factor(GMCSF), granulocyte CSF(G-CSF), chemokine(C-X-C motif) ligand 20(CCL20), and lactate dehydrogenase(LDH). Gram staining was used to evaluate the adhesion of C. glabrata to vaginal epithelial cells. Flow cytometry was utilized to assess the effect of C.glabrata on A431 cell apoptosis. Based on the transcriptomics results, immunofluorescence was performed to measure the expressions of p-EGFR and p-ERK1/2 proteins, while Western blot validated the expressions of p-EGFR, p-ERK1/2, p-C-Fos, p-P38, Bax and Bcl-2 proteins. Sequencing results showed that compared with the VVC model, BEPD treatment up-regulated 1 075 genes and downregulated 927 genes, mainly enriched in immune-inflammatory pathways, including MAPK. Mechanistically, BEPD significantly reduced the expression of p-EGFR, p-ERK1/2, p-C-Fos and p-P38, as well as the secretion of IL-1ß, IL-6, GM-CSF, G-CSF and CCL20, LDH release induced by C. glabrata, and the adhesion of C. glabrata to A431 cells, suggesting that BEPD exerts a protective effect on vaginal epithelial cells damaged by C. glabrata infection by modulating the EGFR/MAPK axis. In addition, BEPD downregulated the pro-apoptotic protein Bax expression and up-regulated the anti-apoptotic protein Bcl-2 expression, leading to a reduction in C. glabrata-induced cell apoptosis. In conclusion, this study reveals that the intervention of BEPD in C. glabrata-induced VVC may be attributed to its regulation of the EGFR/MAPK pathway, which protects vaginal epithelial cells.

[Mechanism of n-butanol extract of Pulsatilla Decoction in treating ulcerative colitis by activating BMP signaling pathway].

The study aimed to investigate the therapeutic effects of the n-butanol extract of Pulsatilla Decoction(BEPD) on ulcerative colitis(UC) via the bone morphogenetic protein(BMP) signaling pathway. C57BL/6 mice were divided into six groups: control, model, mesalazine, and BEPD low-, medium-, and high-dose groups. Except for the control group, the rest groups were treated with 3% dextran sulfate sodium(DSS) freely for seven consecutive days to establish the UC mouse model, followed by treatment with different concentrations of BEPD and mesalazine by gavage. The murine body weight and disease activity index(DAI) were recorded. After the mice were sacrificed, their colon tissues were collected for histological analysis. Alcian blue/periodic acid-Schiff(AB/PAS) staining was used to detect the number and mucus secretion status of goblet cells; immunohistochemistry was performed to measure the expression of ki67, cleaved caspase-3, mucin 2(Muc2), and matrix metalloproteinase-9(MMP9) in colon tissues; and immunofluorescence was used to analyze the expression of tight junction proteins in colon tissues, and enzyme linked immunosorbent assay(ELISA) was employed to quantify the levels of tumor necrosis factor-α(TNF-α), interleukin(IL)-1ß, and IL-6. Western blot was conducted to evaluate the expression of BMP pathway-related proteins in mouse colon tissues. Quantitative real-time PCR(qRT-PCR) was performed to measure the expression of genes related to goblet cell differentiation in mouse colon tissues. In addition, this study also examined the protective effect and underlying mechanism of BEPD-containing serum on lipopolysaccharide(LPS)-induced barrier damages in LS174T goblet cells in vitro. The results showed that BEPD significantly alleviated UC symptoms in mice, restored goblet cell diffe-rentiation function, promoted Muc2 secretion and tight junction protein expression, and suppressed inflammatory factor secretion while activating the BMP signaling pathway. Therefore, BEPD may exert its therapeutic effects on UC by activating the BMP signaling pathway, providing a new strategy for drug intervention in UC.

[Mechanism of n-butanol fraction of Wenxia Formula combining with gefitinib in treating non-small cell lung cancer based on network pharmacology and in vitro experiment].

This study combined network pharmacology, molecular docking, and in vitro experiments to explore the potential mechanism of the active components of the n-butanol fraction of Wenxia Formula(NWXF) combined with gefitinib(GEF) in treating non-small cell lung cancer(NSCLC). Ultra-performance liquid chromatography-quadrupole Orbitrap mass spectrometry(UPLC-Q-Orbitrap MS) was employed to detect the main chemical components of NWXF. The active components of NWXF were retrieved from SwissADME, and the candidate targets of these active components were retrieved from SwissTargetPrediction. Online Mendelian Inheritance in Man(OMIM) and GeneCards were searched for the targets of NSCLC. Cytoscape 3.9.0 and STRING were employed to build the protein-protein interaction(PPI) network with the common targets shared by NWXF and NSCLC. Gene Ontology(GO) annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment were performed in DAVID to predict the potential mechanisms. Finally, molecular docking between the main active ingredients and key targets was conducted in SYBYL-X 2.0. The methyl thiazolyl tetrazolium(MTT) assay was employed to evaluate the inhibitory effects of NWXF and/or GEF on the proliferation of human non-small cell lung cancer cells(A549 and PC-9). Additionally, the impact of NWXF on human embryonic lung fibroblast cells(MRC-5) was assessed. The effectiveness of the drug combination was evaluated based on the Q value. The terminal-deoxynucleoitidyl transferase mediated nick-end labeling(TUNEL) assay was employed to examine the apoptosis of A549 and PC-9 cells treated with NWXF and/or GEF. Quantitative real-time PCR(qRT-PCR) was employed to measure the mRNA levels of epidermal growth factor receptor(EGFR), c-Jun N-terminal kinase(JNK), and Bcl2-associated X protein(Bax) in the A549 and PC-9 cells treated with NWXF and/or GEF. Western blot was employed to determine the protein levels of EGFR, p-EGFR, JNK, p-JNK, and Bax in the A549 and PC-9 cells treated with NWXF and/or GEF. A total of 77 active components, 488 potential targets, and 49 key targets involved in the treatment of NSCLC with NWXF were predicted. The results of GO annotation showed that NWXF may treat NSCLC by regulating the biological processes such as cell proliferation, apoptosis, and protein phosphorylation. KEGG enrichment revealed that the key targets of NWXF in treating NSCLC were enriched in the mitogen-activated protein kinase(MAPK), phosphatidylinositol 3-kinase(PI3K)-protein kinase B(AKT), hypoxia-inducible factor-1(HIF-1), and microRNA-related signaling pathways. Molecular docking results showed that 91.9% of the docking scores were greater than 5, indicating the strong binding capability between main active components and key targets. The cell experiments demonstrated that NWXF combined with GEF synergistically inhibited the proliferation, promoted the apoptosis, decreased p-EGFR/EGFR and p-JNK/JNK values, down-regulated the mRNA levels of EGFR and JNK, and up-regulated the mRNA and protein levels of Bax in A549 and PC-9 cells. In conclusion, NWXF combined with GEF can regulate the EGFR/JNK pathway to promote the apoptosis of NSCLC cells, thus treating NSCLC.

Efforts to install a heterologous Wood-Ljungdahl pathway in Clostridium acetobutylicum enable the identification of the native tetrahydrofolate (THF) cycle and result in early induction of solvents.

Here, we report the construction of a Clostridium acetobutylicum strain ATCC 824 (pCD07239) by heterologous expression of carbonyl branch genes (CD630_0723∼CD630_0729) from Clostridium difficile, aimed at installing a heterologous Wood-Ljungdahl pathway (WLP). As part of this effort, in order to validate the methyl branch of the WLP in the C. acetobutylicum, we performed 13C-tracing analysis on knockdown mutants of four genes responsible for the formation of 5-methyl-tetrahydrofolate (5-methyl-THF) from formate: CA_C3201, CA_C2310, CA_C2083, and CA_C0291. While C. acetobutylicum 824 (pCD07239) could not grow autotrophically, in heterotrophic fermentation, it began producing butanol at the early growth phase (OD600 of 0.80; 0.162 g/L butanol). In contrast, solvent production in the parent strain did not begin until the early stationary phase (OD600 of 7.40). This study offers valuable insights for future research on biobutanol production during the early growth phase.

A dynamic kinetic model captures cell-free metabolism for improved butanol production.

Cell-free systems are useful tools for prototyping metabolic pathways and optimizing the production of various bioproducts. Mechanistically-based kinetic models are uniquely suited to analyze dynamic experimental data collected from cell-free systems and provide vital qualitative insight. However, to date, dynamic kinetic models have not been applied with rigorous biological constraints or trained on adequate experimental data to the degree that they would give high confidence in predictions and broadly demonstrate the potential for widespread use of such kinetic models. In this work, we construct a large-scale dynamic model of cell-free metabolism with the goal of understanding and optimizing butanol production in a cell-free system. Using a combination of parameterization methods, the resultant model captures experimental metabolite measurements across two experimental conditions for nine metabolites at timepoints between 0 and 24 h. We present analysis of the model predictions, provide recommendations for butanol optimization, and identify the aldehyde/alcohol dehydrogenase as the primary bottleneck in butanol production. Sensitivity analysis further reveals the extent to which various parameters are constrained, and our approach for probing valid parameter ranges can be applied to other modeling efforts.

Mathematical modeling of ABE fermentation on glucose substrate with Zn supplementation for enhanced butanol production.

Supplementation or limitation of some micronutrients during acetone-butanol-ethanol (ABE) fermentation has led to improvement in butanol yield and productivity. A mechanistic model of ABE fermentation offers insights in understanding these complex interactions and improving productivity through optimal culture conditions. This study proposes a mechanistic kinetic model of ABE fermentation by two Clostridium Acetobutylicum strains, L7 and ATCC 824 using glucose as sole carbon source without zinc and with various zinc doses. The model incorporates enzyme regulation by zinc on several glycolytic, acidogenesis and solventogenesis enzymes. The model was fitted and validated to experimental data collected from the published literature. The simulated results were in compliance with the experimental data, most importantly indicating higher glucose consumption and butanol productivity when supplemented with zinc compared to the control culture. The average squared correlation factor (R2) between the experimental and the simulated results, without and with zinc, were 0.99 and 0.96 for glucose, and 0.89 and 0.95 for butanol, respectively. A sensitivity analysis performed on the fitted and validated model indicated that the glucose consumption and growth parameters most influenced the model outputs. The developed model can be used as a template for modeling ABE fermentation under different combinations of micronutrients that may offer improved butanol yield and productivity.

Liquid-liquid equilibrium experiment and mechanism analysis of menthol-based deep eutectic solvents extraction for separation of fuel additive tert-butanol.

Deep eutectic solvents (DESs) were synthesized using menthol as hydrogen bond acceptor (HBA) and different carbon chain carboxylic acids as hydrogen bond donors (HBD). The liquid equilibrium (LLE) experiment was used to determine the distribution coefficient (ß) and slectivity (S) at standard atmospheric pressure and temperature. The effect of DESs on the separation efficiency was discussed by changing the proportion. Non-random two fluid (NRTL) model was used to correlate the experimental data. The molecular dynamics (MD) simulation method was used to investigate the micro mechanism of the extraction process. The results show van der Waals force plays a leading role in the interaction between solvents and tert-butyl alcohol (TBA) and week force with water. Compared with experimental and simulation results, the interaction between DESs and TBA would also be affected by the change of the number of HBD carbon chains, and DESs with decanoic acid as HBD has the best separation effect, which verifies the feasibility of separating high alcohol compounds from water by DESs and then treating them by DESs.

Influence of growth substrate and contaminant mixtures on the degradation of BTEX and MTBE by Rhodococcus rhodochrous ATCC strain 21198.

The degradation of the prevalent environmental contaminants benzene, toluene, ethylbenzene, and xylenes (BTEX) along with a common co-contaminant methyl tert-butyl ether (MTBE) by Rhodococcus rhodochrous ATCC Strain 21198 was investigated. The ability of 21198 to degrade these contaminants individually and in mixtures was evaluated with resting cells grown on isobutane, 1-butanol, and 2-butanol. Growth of 21198 in the presence of BTEX and MTBE was also studied to determine the growth substrate that best supports simultaneous microbial growth and contaminants degradation. Cells grown on isobutane, 1-butanol, and 2-butanol were all capable of degrading the contaminants, with isobutane grown cells exhibiting the most rapid degradation rates and 1-butanol grown cells exhibiting the slowest. However, in conditions where BTEX and MTBE were present during microbial growth, 1-butanol was determined to be an effective substrate for supporting concurrent growth and contaminant degradation. Contaminant degradation was found to be a combination of metabolic and cometabolic processes. Evidence for growth of 21198 on benzene and toluene is presented along with a possible transformation pathway. MTBE was cometabolically transformed to tertiary butyl alcohol, which was also observed to be transformed by 21198. This work demonstrates the possible utility of primary and secondary alcohols to support biodegradation of monoaromatic hydrocarbons and MTBE. Furthermore, the utility of 21198 for bioremediation applications has been expanded to include BTEX and MTBE.