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In the current work, we presented the synthesis of N-doped hierarchically porous carbons (NDHPCs) through chemical activation of hierarchically structured precursor derived from polyvinylpyrrolidone (PVP) and magnesium acetate tetrahydrate. Magnesium acetate tetrahydrate served as the blowing agent, and its decomposition product MgO served as the in-situ formed hard template. Combined with KHCO 3 activation, the NDHPCs demonstrated a unique micro- meso -macroporous structure. Owing to the highly porous structure (1560–2545 m2/g) and enriched N-doping (1.48–6.31 wt%), the NDHPCs were investigated as potential CO 2 adsorbents in both post-combustion capture and pre-combustion capture applications. When the adsorption temperature was 25 °C, the samples showed outstanding capture performances at both 1 bar (2.97–3.88 mmol/g) and 20 bar (13.24–19.89 mmol/g). The adsorption performances were further analyzed with grand canonical Monte Carlo (GCMC) simulation. Effects of various physicochemical properties on CO 2 adsorption at different pressures were thus revealed with a combined experimental-theoretical approach. [Display omitted] • NDHPCs with unique micro- meso -macroporous structure are prepared. • The precursor is prepared through chemical blowing and in-situ hard template. • The NDHPCs demonstrate high S BET (1560–2545 m2/g) and N content (1.48–6.31 wt%). • At 25 °C and 20 bar, CO 2 uptake of the NDHPCs reaches 19.89 mmol/g. [ABSTRACT FROM AUTHOR]

In the present study, N-doped hollow carbon nanospheres (NHCNs) were synthesized with a combined soft template-chemical activation method. Spherical hollow hydrochar was prepared from glucose with the assistance of dual soft templates, and was then chemically activated with KHCO 3 and urea to produce the NHCNs. Effects of urea addition and activation temperature on the NHCNs' physicochemical properties were revealed. The NHCNs were endowed with rich N-doping and developed porosity. The sample activated at 800 °C (NHCN2800) showed an impressive specific surface area of 3234 m2/g. The proposed method could also be extended to the synthesis of N, S co-doped hollow carbon nanospheres. We then investigated CO 2 adsorption performances of the NHCNs. At 25 °C and 1 bar, the best CO 2 uptake of the NHCNs was 4.36 mmol/g; at 20 bar, it increased to a record high level of 23.62 mmol/g. Correlations between textural characteristics/N-doping and CO 2 adsorption at 1/20 bar were analyzed and discussed. The current study indicated that the obtained NHCNs had great potential for applications in both pre- and post-combustion CO 2 capture. [Display omitted] • NHCNs are prepared with a combined soft template-chemical activation method. • The NHCNs demonstrate well-defined hollow spherical structure. • The NHCNs exhibit ultrahigh S BET up to 3234 m2/g. • At 25 °C and 20 bar, CO2 uptake of the NHCNs reaches 23.62 mmol/g. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Microporous nitrogen doped carbon is prepared from camphor leaves. • A very high specific surface area of 1736 m2/g is achieved. • Nitrogen doping exhibits positive effects on CO 2 uptake and adsorption selectivity. Abstract In this work, we reported the synthesis of nitrogen doped carbons from camphor tree leaves. The leaves were carbonized and then activated with KOH, and the nitrogen element in the leaves was used as the nitrogen source. The carbon showed a high surface area of 1736 m2/g. A high CO 2 uptake of 5.86 mmol/g at 1 bar and 273 K was achieved by the carbon activated at 600 °C. The test results also revealed that for carbons with similar volume of small micropores, the one with a high nitrogen content tended to achieve better adsorption performances. [ABSTRACT FROM AUTHOR]

[Display omitted] • NSCDCs are prepared with novel organic potassium salts as tri-functional activators. • The organic potassium salts act as activator, N source, and S source simultaneously. • The NSCDCs exhibit high surface area and tunable N/S content. • At 25 °C and 20 bar, CO 2 uptake of the NSCDCs reaches 17.29 mmol/g. In the current work, we proposed the use of two organic potassium salts, 4-morpholineethanesulfonic acid (MES) potassium salt and 1,4-piperazinediethanesulfonic acid (PIPES) dipotassium salt, as novel and tri-functional activators for the synthesis of N, S co-doped carbons (NSCDCs). The organic potassium salts served as activator and N/S source at the same time, allowing direct synthesis of NSCDCs with N/S free precursor. In order to verify this hypothesis, N,S free hydrochar derived from glucose was selected as the carbon source. NSCDCs with high and tunable surface area (1673–2235 m2/g), N content (3.44–5.80 wt%), and S content (5.26–8.72 wt%) were obtained. Physicochemical properties of the carbons were mainly decided by potassium salt and activation temperature. The NSCDCs were also investigated for their CO 2 adsorption properties. At 25 °C and 1 bar, high CO 2 uptake of 3.04–3.99 mmol/g was achieved by the carbons. Q st of the NSCDCs was 22.6–28.7 kJ/mol, and CO 2 adsorption selectivity over N 2 was 10.5–17.3 at 25 °C and 1 bar. At 25 °C and 20 bar, CO 2 uptake increased to 11.26–17.29 mmol/g, and exhibited linear dependence on specific surface area. The current work indicated that MES potassium salt/PIPES dipotassium salt could be used as activator for convenient synthesis of NSCDCs as efficient CO 2 adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] • CTAB assists the synthesis of spherical hydrochar with high yield. • N-doped carbon spheres are synthesized from KHCO 3 activation of the hydrochar. • The carbon spheres exhibit ultrahigh S BET of 3576 m2/g. • Impressively high CO 2 uptake of 35.57 mmol/g is achieved at 0 °C and 20 bar. In the current work, we reported a facile synthesis method for carbon spheres utilizing KHCO 3 activation. Glucose was hydrothermally reacted at 200 °C to produce spherical hydrochar at high yield, and cetyltrimethylammonium bromide (CTAB) was added to mediate the morphology. The hydrochar was then activated with KHCO 3 in the presence of urea. The obtained carbon spheres exhibited ultrahigh specific surface area of 3576 m2/g. It was also found that urea effectively promoted pore formation during activation. Superior CO 2 capture performances were achieved at both 1 and 20 bar. At 25 °C and 1 bar, the carbon spheres showed high CO 2 uptake of 4.26 mmol/g. While at 20 bar, impressively high uptakes of 35.57 mmol/g (0 °C) and 23.04 mmol/g (25 °C) were achieved, which were the highest among the reported results for porous carbons at 20 bar. At 1 bar, ultramicropore (<0.7 nm) was the most important factor in deciding CO 2 uptake, while nitrogen doping significantly enhanced adsorption heat and selectivity. At 20 bar, the uptake showed clear dependence on surface area. The carbon spheres in our work showed great potential in pre-combustion CO 2 capture. [ABSTRACT FROM AUTHOR]

Microporous carbon material with a high surface area of 1562 m 2 /g is prepared via an impregnation method with NaY zeolite as hard template. The results indicate that glucose, an environmental friendly material, could be used as the carbon precursor of zeolite templated carbons, in comparison with the toxicity of furfuryl alcohol and lower surface area of carbons generated from sucrose. Effects of reactant molar ratios and carbonization conditions on the textural properties are addressed. Although higher carbonization temperature favors more complete carbonization reactions, it also causes the collapse of small pores and the formation of large pores at the same time. Further characterizations of the obtained carbon materials with XRD, SEM and N 2 adsorption–desorption measurements are presented. Methane adsorption tests on carbon materials are investigated with the static volumetric method at 300 K. The higher adsorption amount of 9.9 wt.% was achieved at 3.5 MPa on sample with a higher micropore volume, indicating that micropores were playing a crucial role for the methane storage process. [ABSTRACT FROM AUTHOR]

[Display omitted] • N-doped monodisperse carbon nanospheres are prepared using KHCO 3 activation. • KHCO 3 activation favors the perfect preservation of the spherical shape. • The carbon nanospheres show ultrahigh S BET of 3096 m2/g. • CO 2 uptake at 0 °C and 20 bar reaches a strikingly high level of 31.42 mmol/g. Carbon nanospheres are attractive materials with great potentials in many applications. Herein, we presented the synthesis and CO 2 capture of N-doped monodisperse carbon nanospheres with high surface area. Spherical 3-aminophenol-formaldehyde resin with uniform size and shape was used as the precursor, which was then converted into carbon nanospheres through KHCO 3 activation. KHCO 3 activation was the key to the synthesis of carbon spheres, because it led to the formation of highly porous structure with surface area up to 3096 m2/g, and perfectly preserved the spherical shape at the same time. In contrast, the spherical structure was completely destroyed during KOH activation. The carbon nanospheres also showed high nitrogen content of 2.54–8.54 wt%. CO 2 adsorption performances of the carbon nanospheres were studied with pressure up to 20 bar. The carbons showed impressively high uptakes of 31.42/21.55 mmol/g at 0/25 °C and 20 bar, which outperformed many reported results under the same conditions. The correlation between CO 2 adsorption performances and physicochemical properties at different pressures were studied and revealed. [ABSTRACT FROM AUTHOR]

[Display omitted] • N/S co-doped carbon is synthesized with chemical blowing method. • The carbon has a sponge-like hierarchically porous structure. • The S BET of the carbon reaches 1645 m2/g. • Carbon's microporosity is the most critical factor to CO 2 adsorption at 1 bar. • CO 2 uptake at 20 bar correlates with S BET of the carbon. Heteroatom doped carbons have attracted great attentions as CO 2 adsorbents. Herein, we presented a novel and facile strategy for the synthesis of nitrogen and sulfur co-doped carbons (NSCDCs) with chemical blowing method. Chitosan was used as the carbon and nitrogen source, and hydroquinonesulfonic acid potassium salt (HAPS) was used as the sulfur source and blowing agent. NSCDC with hierarchically porous structure was obtained after one-step carbonization of chitosan and HAPS mixture. The carbon exhibited surface area up to 1645 m2/g. HAPS promoted the formation of mesopores and macropores in the carbon. The nitrogen and sulfur contents were 2.54–2.62 and 1.63–6.70 at.%, respectively. NSCDC was also successfully synthesized by replacing chitosan with glucosamine hydrochloride derived hydrochar. The CO 2 adsorption performances of NSCDCs were studied with pressure up to 20 bar. At 25 °C, the best CO 2 uptakes at 1 bar and 20 bar were 2.4 and 12.9 mmol/g, respectively. At 1 bar, the carbon's microporous structure was the most important factor; at 20 bar, the uptake was mainly decided by the total surface area and the pore volume of the carbon. [ABSTRACT FROM AUTHOR]

[Display omitted] • A sustainable process for lutetium separation from LYSO scrap was developed. • Novel diglycolamide-based ionic liquids were synthesized for the extraction process. • The alkali fusion reaction mechanism of LYSO with molten NaOH was revealed. • The process exhibits high REEs extractability with low acid consumption. • Lu(III) can be recovered by three stages of simulated counter-current extraction. As the consumption of rare earth elements (REEs) for many clean energy and consumer electronic sectors continues to grow, recycling REEs is essential due to the limited resources and high economic importance of high-value rare earth (RE). Herein, we describe the development of a novel alkali fusion, acid leaching, and liquid–liquid extraction process for the separation of lutetium from (Lu, Y) 2 SiO 5 (LYSO) scrap using diglycolamide-based task-specific ionic liquids (DGA-TSILs). The comprehensive disintegration of LYSO through alkaline fusion is discussed and subsequently optimized parameters were employed to extract REEs from LYSO under low acidity conditions during hydrochloric acid leaching. Two DGA-TSILs were used for the extraction of Lu(III) and Y(III) from chloride system. McCabe-Thiele diagram was constructed to determine the number of stages needed for the separation of Lu(III) from LYSO leachate, and stripping of Lu(III) from the loaded organic phase was achieved with 0.01 mol/L HCl solution. These results provide a green alternative to conventional methods of strategically important REEs recycling from LYSO scrap. [ABSTRACT FROM AUTHOR]

Abstract: Mesoporous NiO is synthesized with a fast and facile method by using octylamine (OA) and NiCl2·6H2O as template and precursor, respectively. The resultant products are characterized with XRD, DRIFT, SEM, TEM, XPS and nitrogen adsorption–desorption measurements. The synthesis approach is described by the S+X−I+ (OA+Cl−Ni2+) assembly pathway, where the process is mediated by the addition of HCl. The reaction takes place at room temperature and completes in an hour, where the addition of NaOH solution leads to rapid precipitation of Ni(OH)2 and formation of partially ordered mesopores. Nanocrystalline mesoporous NiO is obtained after removal of template and decomposition of Ni(OH)2 upon hot ethanol washing and calcination. The mesopores in NiO are built from the embedded nanocrystallites through template removal and calcination induced cracking. The NiO product achieves a high surface area of 350m2/g after 300°C/3h calcination. The effects of synthetic conditions on the properties of NiO are addressed. [Copyright &y& Elsevier]

Abstract: MnO2 modified NaX zeolites are prepared by dispersion of MnO2 on the surface of NaX in a calcination process. XRD, XPS and N2 adsorption tests confirm that the dispersed MnO2 is primarily monolayer and the calcination conditions affect the dispersion efficiency. The adsorption performances of hydrogen and deuterium of the modified zeolites are investigated at both 77K and 295K. A hydrogen adsorption capacity increase up to 30% is observed at 295K for NaX with moderate MnO2 modification, but the corresponding adsorption at 77K does not show much improvement, and even deteriorates for the samples with high MnO2 contents. NaX shows an adsorption capacity difference of 11% between hydrogen and deuterium at 9bar and 77K, higher than that of MnO2 modified samples (4%); while the difference is much smaller at 295K for all samples. The effects of MnO2 modification on hydrogen adsorption properties are explained by the involvement of Kubas interaction, where Mn in MnO2 acts as a d-electron donor for the enhanced binding of hydrogen molecules. [Copyright &y& Elsevier]

Abstract: The independence number of is defined as the maximum cardinality of a set of pairwise non-adjacent vertices which is called an independent set. In this paper, we characterize the graphs which have the minimum spectral radius among all the connected graphs of order with independence number . [Copyright &y& Elsevier]

L-serine and its derivative L-cysteine have broad industrial applications, and their direct fermentative production from renewable biomass is gaining increasing attention. Corynebacterium glutamicum is an extensively studied and well-established industrial microorganism, which is a predominant microbial host for producing amino acids. In this review, updated information on the genetics and molecular mechanisms underlying L-serine and L-cysteine production using C. glutamicum is presented, including their synthesis and degradation pathways, and other intracellular processes related to their production, as well as the mechanisms underlying substrate import and product export are also analyzed. Furthermore, metabolic strategies for strain improvement are systematically discussed, and conclusions and future perspectives for bio-based L-serine and L-cysteine production using C. glutamicum are presented. This review can provide a thorough understanding of L-serine and L-cysteine metabolic pathways to facilitate metabolic engineering modifications of C. glutamicum and development of more efficient industrial fermentation processes for L-serine and L-cysteine production. [ABSTRACT FROM AUTHOR]

Abstract: A novel rolling method for the preparation of the water management layer (WML) of a PEMFC was developed. In this method, the WML was prepared without dependence on the carbon paper substrate. The obtained WML was in a filmed state. The thickness, PTFE content and sintering condition of the rolled WML film were investigated. The MEA with the WML film exhibited a more stable performance than the MEA without the WML during a long running period. The water management ability of the WML film was confirmed. [Copyright &y& Elsevier]

• Hierarchically porous carbon frameworks (HPCFs) are prepared using hard templates. • The HPCFs have well-defined cubical macropores and abundant micropores. • The HPCFs are successfully doped with nitrogen. • S BET of 100 m2/g corresponds to CO 2 uptake of 0.82 mmol/g at 298 K and 20 bar. Hierarchically porous carbons have triggered lots of research interests due to their unique structure properties. Herein, we presented the synthesis of hierarchically porous carbon frameworks (HPCFs) with the combination of hard template and chemical activation methods. Well-defined cubical macropores were formed by duplication of the hard template's shape, and developed microporosity in the carbon frames was created by NaOH activation. The HPCFs were also successfully doped with nitrogen using urea. Effects of different synthesis parameters on the carbons' morphology and textural properties were analyzed and discussed. The carbon yield could be considered as an indicator of the structure's integrity. Usually the carbon framework collapsed when a very low yield was observed. The carbons' CO 2 adsorption performances were systematically investigated. Effects of nitrogen doping at different pressures were carefully studied. Results from the current and reported works demonstrated that CO 2 uptake at 20 bar depended on the carbons' surface area. The fitting results showed that surface area of 100 m2/g corresponded to CO 2 uptake of 0.82 mmol/g. For CO 2 adsorption under different conditions, heteroatom doped porous carbons with high porosity and lots of small micropores are the most desirable. [ABSTRACT FROM AUTHOR]

The issue of bacterial resistance has become a matter of significant concern globally, prompting extensive research into the development and clinical application of aminoglycoside antibiotics (AGAs) as a crucial antibacterial therapy. One of the primary mechanisms contributing to aminoglycoside antibiotic resistance is the action of aminoglycoside modifying enzymes (AMEs), which modify aminoglycoside antibiotics and consequently confer drug resistance. Chemical modification of the AME action site can eliminate functional groups vulnerable to AMEs, thus improving drug resistance. This study involves the introduction of α‐hydroxy‐γ‐aminobutyric acid and amidine to the 1 and 6′ positions of sisomicin, respectively, to produce a range of 6′‐amidine modified sisomicin derivatives of AGAs. The research evaluates the antibacterial activity, absorption, distribution, metabolism, and excretion (ADME) properties, pharmacokinetic properties, cytotoxicity, nephrotoxicity, and drug resistance of AGAs. The outcomes of this study are significant in terms of enriching the structural understanding of aminoglycosides, providing insight into their structure–activity relationship, and producing new AGAs with high antibacterial activity, low ototoxicity, and nephrotoxicity. [ABSTRACT FROM AUTHOR]

Previously, a novel Corynebacterium glutamicum strain for the de novo biosynthesis of tailored poly-γ-glutamic acid (γ-PGA) has been constructed by our group. The strain was based on the γ-PGA synthetase complex, PgsBCA, which is the only polyprotein complex responsible for γ-PGA synthesis in Bacillus spp. In the present study, PgsBCA was reconstituted and overexpressed in C. glutamicum to further enhance γ-PGA synthesis. First, we confirmed that all the components (PgsB, PgsC, and PgsA) of γ-PGA synthetase derived from B. licheniformis are necessary for γ-PGA synthesis, and γ-PGA was detected only when PgsB, PgsC, and PgsA were expressed in combination in C. glutamicum. Next, the expression level of each pgsB , pgsC , and pgsA was tuned in order to explore the effect of expression of each of the γ-PGA synthetase subunits on γ-PGA production. Results showed that increasing the transcription levels of pgsB or pgsC and maintaining a medium-level transcription level of pgsA led to 35.44% and 76.53% increase in γ-PGA yield (γ-PGA yield-to-biomass), respectively. Notably, the expression level of pgsC had the greatest influence (accounting for 68.24%) on γ-PGA synthesis, followed by pgsB. Next, genes encoding for PgsC from four different sources (Bacillus subtilis , Bacillus anthracis , Bacillus methylotrophicus , and Bacillus amyloliquefacien s) were tested in order to identify the influence of PgsC-encoding orthologues on γ-PGA production, but results showed that in all cases the synthesis of γ-PGA was significantly inhibited. Similarly, we also explored the influence of gene orthologues encoding for PgsB on γ-PGA production, and found that the titer increased to 17.14 ± 0.62 g/L from 8.24 ± 0.10 g/L when PgsB derived from B. methylotrophicus replaced PgsB alone in PgsBCA from B. licheniformis. The resulting strain was chosen for further optimization, and we achieved a γ-PGA titer of 38.26 g/L in a 5 L fermentor by optimizing dissolved oxygen level. Subsequently, by supplementing glucose, γ-PGA titer increased to 50.2 g/L at 48 h. To the best of our knowledge, this study achieved the highest titer for de novo production of γ-PGA from glucose, without addition of L-glutamic acid, resulting in a novel strategy for enhancing γ-PGA production. [ABSTRACT FROM AUTHOR]

• Four different potassium salts are used as highly efficient activators. • The carbons show very high S BET (>2000 m2/g). • Nitrogen content of the carbons is 1.33–6.17 wt%. • CO 2 uptake at 0 °C and 20 bar reaches 26.24 mmol/g. • CO 2 uptake at 20 bar is decided by the carbon's S BET and the total porosity. KOH is one of the most widely used activators for the synthesis of highly porous carbon. However, the strong causticity of KOH could cause serious equipment damage and safety issues at high temperature. In the current work, we presented the synthesis of porous carbons with large surface area using four different potassium salts (CH 3 COOK, KHCO 3 , K 2 CO 3 , and K 2 C 2 O 4 ·H 2 O) as mild but effective activators. Hydrochar prepared from the hydrothermal carbonization of glucosamine hydrochloride was used as carbon precursor. The carbons exhibited specific surface area up to 2403 m2/g. In order to reveal the different influences of nitrogen doping and textural properties under low and high pressure conditions, CO 2 adsorption was tested with pressure up to 20 bar. At 1 bar, ultramicropore was the most determinant factor. Nitrogen doping also showed important influences, especially on the CO 2 /N 2 selectivity. At 20 bar, the carbon activated by KHCO 3 showed CO 2 uptakes of 26.24 (0 °C) and 18.63 mmol/g (25 °C). The experiment results indicated that the uptake at 20 bar correlated with the total surface area and total porosity of the carbon, and no apparent effects from nitrogen doping were observed. [ABSTRACT FROM AUTHOR]

An efficient carbonaceous CO2 adsorbent with doped nitrogen element is derived from agar. Agar was mixed with urea and the mixture was then carbonized. After chemical activation with KOH, nitrogen doped microporous carbon was obtained. The nitrogen content was up to 8.58 wt %, depending on the preparation conditions. The CO2 adsorption properties, including the adsorption isotherms, the isosteric heat of adsorption and the adsorption selectivity were studied. The highest CO2 uptake of 6.5 mmol g−1 (273 K, 1 bar) was achieved by a carbon activated at 600 °C with moderate nitrogen content, while the carbon activated at 550 °C exhibited the best CO2/N2 selectivity of 37. The current work exploits the potential use of agar as carbon precursor for CO2 adsorbent, and provides a convenient and effective approach to nitrogen doping. A very convenient strategy for the preparation of nitrogen containing carbon from biomass was developed in this work. Nitrogen doped carbons were prepared from the mixture of agar and urea. The carbons exhibited high porosity and great potential for the application in CO2 adsorption. A high CO2 uptake of 6.5 mmol g−1 was achieved at 273 K and 1 bar. [ABSTRACT FROM AUTHOR]

Herein, a new strategy of using polyoxometalates (K 3 PW 12 O 40 ) to stabilize sulfur was introduced for the first time for Li-S batteries. The as prepared K 3 PW 12 O 40 spheres/S electrode shows a initial discharge capacity of 1281.0 mAh g −1 with a good cycling stability at a rate of 0.1 C. In particular, the K 3 PW 12 O 40 /S electrode exhibits an initial specific capacity of 810.0 mAh g −1 at a high current rate of 2 C, and remains 560.4 mAh g −1 after 250 cycles. The excellent performances are attributed to the significant roles that K 3 PW 12 O 40 host played during the charge/discharge process. [ABSTRACT FROM AUTHOR]

l -Serine is a non-essential amino acid that has wide and expanding applications in industry with a fast-growing market demand. Currently, extraction and enzymatic catalysis are the main processes for l -serine production. However, such approaches limit the industrial-scale applications of this important amino acid. Therefore, shifting to the direct fermentative production of l -serine from renewable feedstocks has attracted increasing attention. This review details the current status of microbial production of l -serine from renewable feedstocks. We also summarize the current trends in metabolic engineering strategies and techniques for the typical industrial organisms Corynebacterium glutamicum and Escherichia coli that have been developed to address and overcome major challenges in the l -serine production process. [ABSTRACT FROM AUTHOR]

Podocyte injury plays a critical role in diabetic kidney disease (DKD). Our previous work demonstrated a protective role of tyrosine-protein kinase receptor TYRO3 in glomerular disease; However, the downstream signaling of TYRO3 remains unclear. Our data showed that genetic ablation of tyro3 in zebrafish recapitulated a nephrotic syndrome phenotype. TYRO3 expression was suppressed by high glucose and TGF-β, which may contribute to the decreased TYRO3 expression in progressive DKD. Moreover, knockdown of TYRO3 expression with siRNA induced podocytes apoptosis and cytoskeleton rearrangement. Further study revealed that TYRO3 conferred antiapoptotic effects through the activation of JNK/c-jun-P53 in podocytes. Our results revealed a novel signaling module of TYRO3 in podocyte homeostasis, which provides a new molecular insight of TYRO3 effect in podocyte protection. [Display omitted] • Glomerular TYRO3 expression in DN patients closely related to proteinuria and eGFP. • Knockout tyro3 alters glomerular filtration barrier in zebrafish. • TYRO3 conferred protective effects through the activation of JNK/c-jun-P53 in podocytes. [ABSTRACT FROM AUTHOR]

In acute pancreatitis, activation of inflammatory signaling, including the nuclear factor-kappa B (NF-κB) pathway, within acinar cells is known to be an early intracellular event occurring in parallel with pathologic trypsinogen activation. Sphingosine 1-phosphate receptor 2 (S1PR2) plays a critical role in endothelial inflammation, and our previous studies reported that S1PR2 deficiency significantly reduced the inflammatory response in liver injury under cholestasis conditions. However, the role of S1PR2 in inflammatory signaling activation within acinar cells and inflammatory responses during acute pancreatitis has not been elucidated. Here we report that S1PR2 was upregulated in the whole pancreas during acute pancreatitis. Blockade of S1PR2 by pharmacologic inhibition of S1PR2 by JTE-013 or AAV-mediated knockdown of S1PR2 improved the severity of pancreatic injury, as indicated by a significant reduction in inflammation and acinar cells death in acute pancreatitis mice. Moreover, S1PR2 is the predominant S1PRs expressed in pancreatic acinar cells and mediates NF-κB activation and the early inflammatory response within acinar cells under acute pancreatitis conditions via ROCK signaling pathways, not extracellular signal-regulated kinase pathways or p38 mitogen-activated protein kinase pathways. In addition, S1PR2 mediated macrophage NF-κB activation, migration and polarization toward the M1 phenotype. Therefore, these results demonstrated that the S1PR2-mediated early inflammatory response in acinar cells promotes the progression of acute pancreatitis, successfully linking local events to the systematic inflammatory response and leading to a novel therapeutic target for acute pancreatitis aimed at halting the progression of the inflammatory response. 4Upw5czRUXogyYiQEsPybu Video Abstract [ABSTRACT FROM AUTHOR]

Androstenedione (ADD), an important precursor for steroid hormone drug synthesis, can be obtained through the transformation of phytosterols by members of the Mycobacteria genus. In this study, multidirectional pathway engineering of Mycobacterium neoaurum LY-2 was applied to improve ADD production from phytosterols. Initially, the nonessential gene KasB encoding a cell wall β-ketoacyl acyl carrier protein synthase in Mycobacterium neoaurum LY-2 was knocked out, and the production of ADD was increased by 21.0%. Then, the key enzymes involved in ADD synthetic metabolism were systematically explored. These assays revealed that propionyl coenzyme A carboxylase (PCC) and Hsd4A played important roles in the synthesis of ADD. In addition, the heterologous expression of Vitreoscilla hemoglobin (VHb), a protein with oxygen-binding capacity, was successfully realized in Mycobacterium neoaurum LY-2, and the ADD concentration reached 4.42 g/L. Finally, the recombinant strain LY-2- ΔKasB-hsd4A-pcc-vgb with high ADD production was constructed by combining the above strategies. Through optimization of conversion conditions, the recombinant strain LY-2-Δ KasB - hsd4A - pcc-vgb produced an ADD concentration of 11.12 g/L when adding 20 g/L phytosterols. [Display omitted] • Mycobacterium neoaurum LY-2 efficiently catalyzes phytosterols to produce ADD. • Deletion of KasB enhanced the productivity of M. neoaurum LY-2. • PCC, Hsd4A, and VHb were co-expressed in the recombinant strain LY-2-Δ KasB. • The recombinant strain LY-2-Δ KasB - hsd4A - pcc-vgb produced 11.12 g/L of ADD. [ABSTRACT FROM AUTHOR]

• Cordycepin (CRD) could effectively improve hepatic fibrosis in mice fed a diet containing 0.1% DDC. • Cordycepin disrupted quiescent HSCs into proliferative, migratory, contractile, and fibrogenic myofibroblasts. • Cordycepin significantly inhibited glutaminolysis of activated-HSCs and induced cell senescence through the YAP signaling pathway. Cordycepin (CRD) is an active component derived from Cordyceps militaris , which possesses multiple biological activities and uses in liver disease. However, whether CRD improves liver fibrosis by regulating hepatic stellate cell (HSC) activation has remained unknown. The study aims further to clarify the activities of CRD on liver fibrosis and elucidate the possible mechanism. Our results demonstrated that CRD significantly relieved hepatocyte injury and inhibited HSC activation, alleviating hepatic fibrogenesis in the Diethyl 1,4-dihydro-2,4,6-trimethyl-3,5-pyridinedicarboxylate (DDC)-induced mice model. In vitro , CRD exhibited dose-dependent repress effects on HSC proliferation, migration, and pro-fibrotic function in TGF-β1-activated LX-2 and JS-1 cells. The functional enrichment analysis of RNA-seq data indicated that the pathway through which CRD alleviates HSC activation involves cellular senescence and cell cycle-related pathways. Furthermore, it was observed that CRD accumulated the number of senescence-associated a-galactosidase positive cells and the levels of senescence marker p21, and provoked S phase arrest of activated HSC. Remarkably, CRD treatment abolished TGF-β‐induced yes-associated protein (YAP) nuclear translocation that acts upstream of glutaminolysis in activated HSC. On the whole, CRD significantly inhibited glutaminolysis of activated-HSC and induced cell senescence through the YAP signaling pathway, consequently alleviating liver fibrosis, which may be a valuable supplement for treating liver fibrosis. [ABSTRACT FROM AUTHOR]

CYP68JX, a P450 hydroxylase, derived from Colletotrichum lini ST-1 is capable of biotransforming dehydroepiandrosterone (DHEA) to 3β,7α,15α-trihydroxy-5-androstene-17-one (7α,15α-diOH-DHEA). Redox partners and cofactor supply are important factors affecting the catalytic activity of CYP68JX. In this study, the heterologous expression of CYP68JX in Saccharomyces cerevisiae BY4741 was realized resulting in a 17.1% target product yield. In order to increase the catalytic efficiency of CYP68JX in S. cerevisiae BY4741, a complete cytochrome P450 redox system was constructed. Through the combination of CYP68JX and heterologous CPRs, the yield of the target product 7α,15α-diOH-DHEA in CYP68JX recombinant system was increased to 37.8%. Furthermore, by adding NADPH coenzyme precursor tryptophan of 40 mmol/L and co-substrate fructose of 20 g/L during the conversion process, the catalytic efficiency of CYP68JX was further improved, the target product yield reached 57.9% which was 3.39-fold higher than initial yield. Overall, this study provides a reference for improving the catalytic activity of P450s. • CYP68JX achieved heterologous expression in Saccharomyces cerevisiae. • The combination of CYP68JX and AtCPR increased the catalytic efficiency. • Adding tryptophan and fructose improved NADPH supply. [ABSTRACT FROM AUTHOR]

• The interaction between lncRNAs and tyrosine kinases (TKs) and their regulatory network in drug resistance of pancreatic cancer. • The mechanism of TKs mediated drug resistance in pancreatic cancer. • The promotive and suppressive roles of lncRNAs play in drug resistance of pancreatic cancer. • The clinical relevance of targeting TKs and lncRNAs. Pancreatic cancer (PC) is one of the most malignant tumors with a dismal survival rate, this is primarily due to inevitable chemoresistance. Dysfunctional tyrosine kinases (TKs) and long non-coding RNAs (lncRNAs) affect the drug resistance and prognosis of PC. Here, we summarize the mechanisms by which TKs or lncRNAs mediate drug resistance and other malignant phenotypes. We also discuss that lncRNAs play oncogenic or tumor suppressor roles and different mechanisms including lncRNA-proteins/microRNAs to mediate drug resistance. Furthermore, we highlight that lncRNAs serve as upstream regulators of TKs mediating drug resistance. Finally, we display the clinical significance of TKs (AXL, EGFR, IGF1R, and MET), clinical trials, and lncRNAs (LINC00460, PVT1, HIF1A-AS1). In the future, TKs and lncRNAs may become diagnostic and prognostic biomarkers or drug targets to overcome the drug resistance of PC. [ABSTRACT FROM AUTHOR]

The dietary supplementation of prebiotics is considered a promising strategy for the modulation of gut microbiota. Due to the wide variety of animal models and tremendous inter-individual variability from human investigations, the prebiotic effect of fibers is often difficult to compare between studies. Here, the effects of 11 dietary fibers on human fecal microbiota were studied using an in vitro human fecal fermentation model under well-controlled conditions. All fibers showed positive regulatory effects on short chain fatty acids (SCFAs) and several beneficial bacteria, including Parabacteroides distasonis and Bifidobacterium spp. Cultures supplemented with xylo-oligosaccharide and konjac flour showed the highest SCFAs. According to regulatory effects, fibers were divided into three groups, with 13 indicator OTUs (operational taxonomic units) identified. Fecal microbiota regulated by isomalto-oligosaccharide and chitosan-oligosaccharide were similar to fructo-oligosaccharide and inulin outputs. As a supplement to in vivo studies, our results comprehensively summarized the similarities and distinctiveness of fibers in regulating fecal microbiota structures. Key points: • Fibers were divided into three groups based on the regulatory effects in microbiota. • Thirteen indicator OTUs were identified using pairwise comparisons. • Fiber similarities and distinctive traits in regulating microbiota effect were identified. [ABSTRACT FROM AUTHOR]

Homologs of PtxS are ubiquitous transcriptional regulators controlling the expression of the glucose dehydrogenase and kgu operon to globally regulate the 2-ketogluconic acid (2KGA) metabolism in Pseudomonas. In the present study, a PtxS from a 2KGA industrial producer Pseudomonas plecoglossicida JUIM01 (PpPtxS) was heterologously expressed in E. coli BL21(DE3), then structurally and functionally characterized. The obtained results showed that PpPtxS was a 36.65-kDa LacI-family transcriptional regulator. 2KGA was the sole effector of PpPtxS. Glucose negatively affected the molecular binding of PpPtxS and 2KGA, and gluconic acid inhibited the PpPtxS-2KGA binding reaction. PpPtxS in water solution mainly existed as a dimer and bound to two molecules of 2KGA. The effector 2KGA mainly bound to the region close to the C-terminal of PpPtxS by interacting with the 299th to the 301st amino acids (Ala, Gln, Pro, Thr, Glu and Arg). PpPtxS specifically recognized and bound to a 14-bp palindrome sequence (5′-TGAAACCGGTTTCA-3′) due to its conserved HTH motif at the N-terminal. The characterization of PpPtxS in this study would provide a theoretical guidance for the industrial production of 2KGA. • PtxS from a 2KGA industrial producer P. plecoglossicida was heterologously expressed. • PpPtxS was a 36.65-kDa LacI-family transcriptional regulator. • PpPtxS had a sole effector of 2KGA. • PpPtxS was mainly dimeric in water solution and bound to two molecules of 2KGA. • PpPtxS specifically recognized and bound to a 14-bp palindrome sequence. [ABSTRACT FROM AUTHOR]

Background: Cell type-specific transcriptional programming results from the combinatorial interplay between the repertoire of active regulatory elements. Disease-associated variants disrupt such programming, leading to altered expression of downstream regulated genes and the onset of pathological states. However, due to the non-linear regulatory properties of non-coding elements such as enhancers, which can activate transcription at long distances and in a non-directional way, the identification of causal variants and their target genes remains challenging. Here, we provide a multi-omics analysis to identify regulatory elements associated with functional kidney disease variants, and downstream regulated genes. Results: In order to understand the genetic risk of kidney diseases, we generated a comprehensive dataset of the chromatin landscape of human kidney tubule cells, including transcription-centered 3D chromatin organization, histone modifications distribution and transcriptome with HiChIP, ChIP-seq and RNA-seq. We identified genome-wide functional elements and thousands of interactions between the distal elements and target genes. The results revealed that risk variants for renal tumor and chronic kidney disease were enriched in kidney tubule cells. We further pinpointed the target genes for the variants and validated two target genes by CRISPR/Cas9 genome editing techniques in zebrafish, demonstrating that SLC34A1 and MTX1 were indispensable genes to maintain kidney function. Conclusions: Our results provide a valuable multi-omics resource on the chromatin landscape of human kidney tubule cells and establish a bioinformatic pipeline in dissecting functions of kidney disease-associated variants based on cell type-specific epigenome. [ABSTRACT FROM AUTHOR]

Our previous study has revealed that Pseudomonas plecoglossicida JUIM01 produced 2-keto- d -gluconic acid (2KGA) and re-utilized 2KGA as an alternative carbon source to support cell growth after complete consumption of glucose. Phosphorylation of intracellular 2KGA to 2-keto-6-phosphogluconic acid by 2-ketogluconate kinase (KguK) was regarded as the first step of 2KGA catabolism in Pseudomonas cytoplasm. In the present study, a kguK gene encoding 2-ketogluconate kinase from P. plecoglossicida JUIM01 was cloned and heterologously expressed in Pichia pastoris. The recombinant KguK showed the highest activity at 30–33 °C and pH 7.7, and high stability at 33 °C. Under the optimal conditions of 30 °C and pH 7.7 with addition of 5 mM Mg2+, the purified and concentrated (~30 folds) KguK had a specific activity of 3649.6 U/g and a Michaelis constant for 2KGA of 8.7 × 10−4 M. Knockout of kguK could retard but not completely inhibit 2KGA catabolism, indicating other existing 2KGA utilization pathway(s). The kguK -knockout P. plecoglossicida significantly reduced 2KGA re-utilization without negative effects on cell growth, glucose consumption or 2KGA production. The outputs demonstrated kguK knockout could be an effective strategy to develop the alternative 2KGA high-producing Pseudomonas strains to avoid the decrease of 2KGA yield caused by its re-utilization. • A kguK gene was heterelogously expressed from 2KGA producer P. plecoglossicida. • The recombinant KguK of P. plecoglossicida was enzymatically characterized. • Knockout of kguK significantly reduced 2KGA re-utilization after complete consumption of glucose. • Knockout of kguK is a strategy to develop 2KGA high-producing Pseudomonas strains. [ABSTRACT FROM AUTHOR]

Acute pancreatitis (AP) is a noninfectious inflammatory disease with high morbidity and mortality, which is characterized by severe inflammation and tissue necrosis. Cordycepin (CRD), derived from Cordyceps militaris , possesses anti-inflammatory effects and immunomodulation properties. Here, we investigated the protective effects of CRD on pancreatic injury and clarified potential mechanisms in AP model. There were established caerulein-induced AP and CRD pretreatment models in vivo and in vitro, as showed by serum enzymes, histopathological alterations and pro-inflammatory cytokines. Pretreatment with CRD notably downregulated the serum amylase and lipase levels and apparently reduced pancreatic histopathological alterations in AP mice. Meanwhile, the MPO staining confirmed that CRD pretreatment modulated the infiltration of neutrophils in AP mice. Furthermore, CRD markedly decreased the levels of pro-inflammatory factors (IL-6, IL-1β, and TNF-α) though inhibiting the activation of nuclear factor-κB (NF-κB) and NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome in AP mice. In pancreatic acinar cancer cell 266-6, CRD pretreatment decreased cholecystokinin(CCK)-induced inflammatory response was consistent with those in vivo. Mechanistically, CRD was also revealed to activate activated protein kinase (AMPK) and attenuated inflammation both in vivo and in vitro. On the whole, this study indicated that CRD protects mice from pancreatic inflammatory process and damage by suppressed NF-κB and NLRP3 inflammasome activation via AMPK, which probably contributed to the potential therapy for AP. [ABSTRACT FROM AUTHOR]

• A new N, N-di(2-ethylhexyl)-diglycolamide grafted polymer resin is prepared. • The polymer resin exhibits enhanced adsorption capacity towards trace RE(III). • Purification of REEs from a mixture containing Al(III) and Fe(III) is achieved. • Efficient reusability of the polymer resin is demonstrated. Separation of rare earth elements (REEs) from dilute solutions using liquid-liquid extraction is often plagued by third phase formation and multiple sequential extraction steps. A new system based on the N, N-di(2-ethylhexyl)-diglycolamide (DEHDGA) grafted polymer resin, used for the efficient separation of RE(III) are proposed. Upon grafting of DEHDGA ligand, the resulting polymer resin was evaluated for its RE(III) adsorption performance. By using a combination of pH-dependent adsorption, kinetics and equilibrium adsorption isotherms experiments, the results suggest that adsorption behavior of the resin for RE(III) is mainly influenced by pH, and thus a competitive adsorption model is proposed to simultaneously describe the adsorption of RE(III) and protons. The proposed resin demonstrates enhanced selectivity towards RE(III) in the presence of Al(III) and Fe(III) compared to the DGA-normal resin at pH 3.0. These results establish that the polymer skeleton could provide a favorable geometry of DEHDGA ligand for complexing RE(III) through the carbonyl and ether groups, which is supported by the FT-IR and XPS analysis of prepared RE(III)-loaded resin. Furthermore, the polymer resin could be reused after four consecutive cycles without substantial loss of adsorption ability, offering a facile process for highly efficient REEs separation from a low concentration of leaching solution. [ABSTRACT FROM AUTHOR]

The preparation and application of heteroatom doped carbons have attracted lots of attention in the past years. In the current work, a facile synthesis of nitrogen doped carbon with filter paper as the carbon source and urea as the nitrogen source was presented. Filter paper was first impregnated with urea solution, and was then carbonized and activated. The carbons' physical and chemical properties were studied. For the application in CO 2 adsorption, impacts from porous characteristics and nitrogen doping were discussed and differentiated. The results suggested that nitrogen doping was beneficial to the improvement of CO 2 uptake, but suitable porous properties were the most important factors. Nitrogen doping showed more significant effects on enhancing the adsorption heat and selectivity. The research of carbonaceous CO 2 adsorbent should focus on nitrogen doped carbons with high porosity. • Urea loaded filter paper is used as starting material for nitrogen doped carbon. • Effects of nitrogen doping and porous structure on CO 2 adsorption are studied. • CO 2 uptake at 273 K and 1 bar reaches 5.12 mmol/g. • Nitrogen doping has obvious effects on CO 2 adsorption heat and selectivity. [ABSTRACT FROM AUTHOR]

Background: l-Serine has wide and increasing applications in industries with fast-growing market demand. Although strategies for achieving and improving l-serine production in Corynebacterium glutamicum (C. glutamicum) have focused on inhibiting its degradation and enhancing its biosynthetic pathway, l-serine yield has remained relatively low. Exporters play an essential role in the fermentative production of amino acids. To achieve higher l-serine yield, l-serine export from the cell should be improved. In C. glutamicum, ThrE, which can export l-threonine and l-serine, is the only identified l-serine exporter so far. Results: In this study, a novel l-serine exporter NCgl0580 was identified and characterized in C. glutamicum ΔSSAAI (SSAAI), and named as SerE (encoded by serE). Deletion of serE in SSAAI led to a 56.5% decrease in l-serine titer, whereas overexpression of serE compensated for the lack of serE with respect to l-serine titer. A fusion protein with SerE and enhanced green fluorescent protein (EGFP) was constructed to confirm that SerE localized at the plasma membrane. The function of SerE was studied by peptide feeding approaches, and the results showed that SerE is a novel exporter for l-serine and l-threonine in C. glutamicum. Subsequently, the interaction of a known l-serine exporter ThrE and SerE was studied, and the results suggested that SerE is more important than ThrE in l-serine export in SSAAI. In addition, probe plasmid and electrophoretic mobility shift assays (EMSA) revealed NCgl0581 as the transcriptional regulator of SerE. Comparative transcriptomics between SSAAI and the NCgl0581 deletion strain showed that NCgl0581 is a positive regulator of NCgl0580. Finally, by overexpressing the novel exporter SerE, combined with l-serine synthetic pathway key enzyme serAΔ197, serC, and serB, the resulting strain presented an l-serine titer of 43.9 g/L with a yield of 0.44 g/g sucrose, which is the highest l-serine titer and yield reported so far in C. glutamicum. Conclusions: This study provides a novel target for l-serine and l-threonine export engineering as well as a new global transcriptional regulator NCgl0581 in C. glutamicum. [ABSTRACT FROM AUTHOR]

The riverine dissolved solids, indicating the environment information in watersheds, generally originated from rock weathering, soil erosion and anthropogenic inputs etc. The hydro-chemical characteristics of Danjiangkou Reservoir and its influencing factors after the implementation of South-to-North Water Transfer Project were discussed, based on water quality investigation from October 2017 to July 2018. The water in Danjiangkou Reservoir was moderately alkalescent, with pH ranging from 7.02 to 8.58. The dissolved oxygen, oxidation–reduction potential and conductivity had showed obviously seasonal variations. The total dissolved solids average was 176.14 ± 15.98 mg/L, which was much higher than that average of main rivers in the world. The Ca2+ concentration was the highest among cationic composition, accounting for 50% to 70% of total cations. Among the anion composition, HCO 3 - concentrations accounted for more than 70% in most sampling points. Researches showed that carbonates weathering had contributed 70.1% of chemical compositions and mainly controlled the hydro-chemical characteristics. Some riverine ions were affected by silicates weathering. The 17.75% of chemical species were released into rivers by anthropogenic inputs, which proved to be the important factors affecting riverine chemical characteristics, especially in the wet season. [ABSTRACT FROM AUTHOR]

• The 9α-hydroxyandrost-4-ene-3,17-dione is a key intermediate of steroid drugs. • A nonionic surfactant is selected based on hydrophilic-lipophilic balance values. • Polyoxyethylene (10) nonylphenyl ether enhanced phytosterol solubility by 12.1-fold. • The 9α-hydroxyandrost-4-ene-3,17-dione molar yield increased to 42.5%. The 9α-hydroxyandrost-4-ene-3,17-dione (9α−OH-AD) is a key intermediate for synthetizing steroid pharmaceutical compounds. It is bioconverted by Mycobacterium sp. LY-1 from phytosterols. During biotransformation, the low solubility of phytosterols in water limits 9α−OH-AD production. In the present work, polyoxyethylene (10) nonylphenyl ether (TX-40), a nonionic surfactant, was first used to enhance phytosterol solubility during 9α−OH-AD biotransformation. In the presence of 0.7% TX-40, phytosterol solubility was increased 12.1-fold, and the 9α−OH-AD molar yield reached 42.5% at the phytosterols concentration of 15 g/L, an increase of 217.2% over controls. The improvement is sufficient to replace the traditional process of adding soybean oil. Scanning electron microscopy showed that the extracellular membrane-like structure was loosened by TX-40, but cells maintained their integrity. The fatty acid profile of Mycobacterium sp. LY-1 cells revealed that TX-40 altered the composition of the cell membrane and improved its permeability. The transcript levels of key enzymes involved in cell membrane lipid synthesis were downregulated significantly upon TX-40 addition compared with controls. These results demonstrated that the increase in product molar yield by TX-40 was primarily related to easier substrate transportation across the cell membrane of Mycobacterium sp. LY-1. [ABSTRACT FROM AUTHOR]

γ-Polyglutamic acid (γ-PGA) is a biodegradable polymer naturally produced by Bacillus spp. that has wide applications. Fermentation of γ-PGA using Bacillus species often requires the supplementation of L-glutamic acid, which greatly increases the overall cost. Here, we report a metabolically engineered Corynebacterium glutamicum capable of producing γ-PGA from glucose. The genes encoding γ-PGA synthase complex from B. subtilis (pgsB , C , and A) or B. licheniformis (capB , C , and A) were expressed under inducible promoter P tac in a L-glutamic acid producer C. glutamicum ATCC 13032, which led to low levels of γ-PGA production. Subsequently, C. glutamicum F343 with a strong L-glutamic acid production capability was tested. C. glutamicum F343 carrying capBCA produced γ-PGA up to 11.4 g/L, showing a higher titer compared with C. glutamicum F343 expressing pgsBCA. By introducing B. subtilis glutamate racemase gene racE under P tac promoter mutants with different expression strength, the percentage of L-glutamic acid units in γ-PGA could be adjusted from 97.1% to 36.9%, and stayed constant during the fermentation process, while the γ-PGA titer reached 21.3 g/L under optimal initial glucose concentrations. The molecular weight (M w) of γ - PGA in the engineered strains ranged from 2000 to 4000 kDa. This work provides a foundation for the development of sustainable and cost-effective de novo production of γ-PGA from glucose with customized ratios of L-glutamic acid in C. glutamicum. Image 1 • Inducible expression of the γ-PGA synthase can lead to de novo synthesis of γ-PGA. • Limited supply of L-glutamate in C. glutamicum restricts the synthesis of γ-PGA. • The stereochemistry of γ-PGA can be tailored by regulating the expression of rac E. [ABSTRACT FROM AUTHOR]

[Display omitted] • CsHCO 3 is used as effective chemical activator to synthesize porous carbons. • The carbons exhibit S BET of 1251–2746 m2/g. • An impressively high CO 2 uptake of 4.64 mmol/g is achieved at 25 °C and 1 bar. • At 25 °C and 20 bar, CO 2 uptake of the carbons reaches 22.12 mmol/g. In the current work, highly porous carbons were prepared from CsHCO 3 activation of glucosamine hydrochloride derived hydrochar. Carbon materials with surface area of 1251–2746 m2/g were obtained at high yield of 42.5–49.9%. The carbons demonstrated remarkable CO 2 adsorption capabilities at both 1 and 20 bar. At 25 °C, an impressively high CO 2 uptake of 4.64 mmol/g was achieved, and it increased to 22.12 mmol/g at 20 bar. The current work shows that CsHCO 3 can be used as a highly effective activator in preparing porous carbons for CO 2 adsorption. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous carbons are prepared from the direct pyrolysis of potassium cinnamate. • N-doped porous carbons can be obtained when urea is added. • The carbons show high S BET up to 2198 m2/g. • A high CO 2 uptake of 3.92 mmol/g is achieved at 25 °C and 1 bar. In the current work, honeycomb-like porous carbons were prepared from the direct pyrolysis of potassium cinnamate without the use of any activators or templates. The carbons' surface area reached 2198 m2/g. N-doped porous carbons were also prepared by co-pyrolysis of potassium cinnamate and urea. Effects of the pyrolysis temperature on textural properties and N-doping were studied. CO 2 adsorption performances of the carbons were investigated at 0 and 25 °C. A high CO 2 uptake of 3.92 mmol/g was achieved at 25 °C and 1 bar. [ABSTRACT FROM AUTHOR]

The metabolic mechanism of excessive exopolysaccharide (BMPS) synthesis by Bacillus mucilaginosus CGMCC5766 under CaCO3 addition was investigated. Under CaCO3 (5 g/L), the maximum BMPS concentration reached 28.4 g/L, which was 11.2 folds higher than that of the control. Proteomics was then used to analyze the proteins with substantial differences expressed by B. mucilaginosus with and without CaCO3 addition. The proteomic results revealed that the enzymes related to the central metabolic pathway, amino acid biosynthesis, and nucleotide metabolism were depressed. By contrast, the UDP–glucose pyrophosphorylase involved in BMPS biosynthesis was overexpressed and converted metabolic flux from the biomass accumulation to the biosynthesis of BMPS. This research provides a new and widened perspective into understanding the mechanism of BMPS biosynthesis and applying theoretical and practical significance for the improvement of BMPS production from B. mucilaginosus. [ABSTRACT FROM AUTHOR]

L-Serine is widely used in pharmaceutical, food and cosmetic industries, and the direct fermentation to produce L-serine from cheap carbon sources such as glycerol is greatly desired. The production of L-serine by engineered Escherichia coli from glycerol has not been achieved so far. In this study, E. coli was engineered to efficiently produce L-serine from glycerol. To this end, three L-serine deaminase genes were deleted in turn, and all of the deletions caused the maximal accumulation of L-serine at 0.06 g/L. Furthermore, removal of feedback inhibition by L-serine resulted in a titer of 1.1 g/L. Additionally, adaptive laboratory evolution was employed to improve glycerol utilization in combination with the overexpression of the cysteine/acetyl serine transporter gene eamA, leading to 2.36 g/L L-serine (23.6% of the theoretical yield). In 5-L bioreactor, L-serine titer could reach up to 7.53 g/L from glycerol, demonstrating the potential of the established strain and bioprocess. [ABSTRACT FROM AUTHOR]

Abstract Alginate oligosaccharides are depolymerization products of alginate by enzymatic degradation or physicochemical treatments. Alginate lyase has received great interests due to its use in oligosaccharide preparation. The substrate specificity of alginate lyase directly determines the type and degree of polymerization of alginate oligosaccharides. In this paper, the degradation products of Alginate lyase from Isoptericola halotolerans CGMCC 5336 were size-fractionated by gel filtration chromatography and the fractions were characterized by TLC, HPLC, MS and 1H NMR spectroscopy. The Mw values for these fractions were 352, 528, 704 Da which represented di-, tri-, and tetrasaccharide fragments, respectively. The 1H NMR revealed that the non-reducing ends of these oligosaccharides were 4-deoxy-L-erythro-hex-4-enepyranosyluronate and the reducing ends of these oligosaccharides were all guluronic acid. Therefore, it is believed that the alginate lyase produced by Isoptericola halotolerans CGMCC 5336 was capable of performing β elimination on guluronic acid residue so that low molecular weight oligosaccharides with guluronic acid on the reducing end could be obtained in this way. Graphical abstract Image 1 Highlights • Association of enzymatic activity with residue neighbor to enzyme cutting site. • The enzyme is a G-lyase only acting on G–M OR G-G diads. • The unsaturated oligosaccharides with guluronic as reducing end were produced and isolated. [ABSTRACT FROM AUTHOR]

L-Serine is widely used in the pharmaceutical, food, and cosmetics industries. Although direct fermentative production of L-serine from sugar in Corynebacterium glutamicum has been achieved, the L-serine yield remains relatively low. In this study, atmospheric and room temperature plasma (ARTP) mutagenesis was used to improve the L-serine yield based on engineered C. glutamicum ΔSSAAI strain. Subsequently, we developed a novel high-throughput screening method using a biosensor constructed based on NCgl0581, a transcriptional factor specifically responsive to L-serine, so that L-serine concentration within single cell of C. glutamicum can be monitored via fluorescence-activated cell sorting (FACS). Novel L-serine-producing mutants were isolated from a large library of mutagenized cells. The mutant strain A36-pDser was screened from 1.2 × 105 cells, and the magnesium ion concentration in the medium was optimized specifically for this mutant. C. glutamicum A36-pDser accumulated 34.78 g/L L-serine with a yield of 0.35 g/g sucrose, which were 35.9 and 66.7% higher than those of the parent C. glutamicum ΔSSAAI-pDser strain, respectively. The L-serine yield achieved in this mutant was the highest of all reported L-serine-producing strains of C. glutamicum. Moreover, the whole-genome sequencing identified 11 non-synonymous mutations of genes associated with metabolic and transport pathways, which might be responsible for the higher L-serine production and better cell growth in C. glutamicum A36-pDser. This study explored an effective mutagenesis strategy and reported a novel high-throughput screening method for the development of L-serine-producing strains. [ABSTRACT FROM AUTHOR]

7α,15α-diOH-Dehydroepiandrosterone (7α,15α-diOH-DHEA) is an important intermediate in the synthesis of steroid pharmaceutical compounds, and can be bioconverted from DHEA by Colletotrichum lini ST-1 . A microemulsion system can improve substrate bioavailability and may also minimize DHEA cellular toxicity as cells and substrate are retained in the water and oil phase respectively. In this study, several microemulsions with a different hydrophile lipophile balance were prepared and evaluated based on their stability and bioconversion efficacy. The yield of the best formula of 7α,15α-diOH-DHEA was 61.2%, which was 3.1 times that of the traditional water phase bioconversion system. This formula was further optimized using the Taguchi orthogonal experimental design, and the yield reached 73.3%. Due to less cellular toxicity of the substrate using the microemulsion system, the repeated-cycle bioconversion based on microemulsion using recycled cells was realized for the first time, and the overall 6-cycle production (41.5 g from 60 g DHEA) was 4.3 times that of the traditional method. This highly efficient microemulsion system, with improved cell sustainability as well as bioreactivity, may be expanded to the bioconversion of other insoluble and toxic substrates. [ABSTRACT FROM AUTHOR]

Steviol glycosides have attracted great interest because of their high levels of sweetness and safety, and absence of calories. Improvement of their sensory qualities via glycosylation modification by glycosyltransferase is a research hotspot. In this study, YjiC, a uridine diphosphate-dependent glycosyltransferase from Bacillus subtilis 168, was found with the ability to glycosylate rebaudioside A (Reb A) to produce a novel mono β -1, 6-glycosylated Reb A derivative rebaudioside L2 (Reb L2). It has an improved sweetness compared with Reb A. Next, a cascade reaction was established by combining YjiC with sucrose synthase At SuSy from Arabidopsis thaliana for scale-up preparation of Reb L2. It shows that Reb L2 (30.94 mg/mL) could be efficiently synthesized with an excellent yield of 91.34% within 12 h. Therefore, this study provides a potential approach for the production and application of new steviol glycoside Reb L2, expanding the scope of steviol glycosides. [Display omitted] • A glycosyltransferase YjiC from B. subtilis 168 was reported to synthesize a novel mono β -1,6-glycosylated Reb A derivative. • It was firstly reported that YjiC could realize the construction of β -1,6-glycosidic linkage. • Cascade reaction system with YjiC and sucrose synthase At SuSy from Arabidopsis thaliana was established to regenerate UDPG. • 29.01 mg/mL Reb A was transformed into 30.94 mg/mL Reb L2 with 91.34% yield in the cell lysate. [ABSTRACT FROM AUTHOR]

3β,7α,15α-Trihydroxy-5-androsten-17-one (7α,15α-diOH-DHEA) is a key intermediate of the novel oral contraceptive Yasmin. It can be catalyzed from dehydroepiandrosterone (DHEA) through Colletotrichum lini. Improvement of 7α,15α-diOH-DHEA production was performed through recursive protoplast fusion of C. lini ST in a genome shuffling format. 7α,15α-diOH-DHEA yield of the best performing recombinant C. lini ST-F307 reached 6.08 g/L from 10 g/L DHEA, and this was 94.9% higher than that of the initial C. lini ST strain. Through optimized conditions, the 7α,15α-diOH-DHEA yield was increased to 9.32 g/L from 12 g/L DHEA, with 1.5% ethanol as cosolvent. This is the highest reported substrate concentration and 7α,15α-diOH-DHEA production with one-step substrate addition. Moreover, C. lini ST-F307 showed high P450 enzyme activity and gene transcript levels of several cytochrome P450s, and this might contribute to the enhancement of 7α,15α-diOH-DHEA production. Genome shuffling was an efficient approach to breed high-yield strains. [ABSTRACT FROM AUTHOR]

Pyruvate kinase (PYK) is an important enzyme in the intermediary metabolism and has attracted much attention as a target for metabolic engineering of Corynebacterium glutamicum . Genome sequencing revealed that the 308 residue of PYK was mutated from methionine in model strain C. glutamicum ATCC14067 to isoleucine in L-serine-producing strain C. glutamicum SYPS-062. Consequently, a significantly lower PYK activity (77%) was noted in C. glutamicum SYPS-062, when compared with that in C. glutamicum ATCC14067. To confirm the role of this point mutation, pyk in both C. glutamicum SYPS-062 and C. glutamicum SYPS-062-33aΔSSAA was reversely mutated to restore the PYK enzyme activity, which led to a 33.1% and 28.8% decrease in L-serine titer, respectively. This is the first report to show that the (Met-308→Ile) mutation site of pyk is closely associated with its activity and apparently affected L-serine production. Furthermore, pyk was deleted in strain C. glutamicum SYPS-062-33aΔSSAA, and the resulting strain did not show alteration in growth rate and presented a 12% increase in L-serine production. [ABSTRACT FROM AUTHOR]

Microbial fermentative production of l -serine has attracted increasing attention, and in our previous study, Corynebacterium glutamicum- SYPS - 062ΔSSA has been successfully screened and engineered to produce l -serine from sucrose. It was noticed that there was significant fructose accumulation during l -serine fermentation process using sucrose as substrates, which is the preferred carbon resource for this strain. Lack of fructokinase may be responsible for poor fructose utilization. In the present study, a shortcut pathway for fructose utilization has been constructed via heterologous expression of scrK (fructokinase). Furthermore, pfkA (phosphofructokinase) was over-expressed to avoid over accumulation of fructose-6-phosphate, the resulting strain showed significantly improved cell growth and l -serine accumulation. In a 5-L bioreactor, the engineered C. glutamicum strain produced 30.6 g/L l -serine (0.99 mol/mol sucrose yield, with a theoretical maximal yield of 4 mol/mol sucrose), whereas the reference strain produced 20.54 g/L l -serine (with a yield of 0.67 mol/mol sucrose) at 120 h. After two feedings of sucrose, the l -serine production increased up to 37.0 g/L at 96 h. [ABSTRACT FROM AUTHOR]