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•Y. lipolytica is a superior industrial host for the production of lipids.•Lipid metabolic pathway in Y. lipolytica and the potential engineering targets are introduced.•Metabolic ...engineering strategies for increasing lipid accumulation in Y. lipolytica are summarized.•Systems and synthetic biology tools will further push the lipid yields to the theoretical limits.•Perspectives for novel engineering approaches for increasing lipid accumulation in Y. lipolytica are discussed.
Current energy security and climate change policies encourage the development and utilization of bioenergy. Oleaginous yeasts provide a particularly attractive platform for the sustainable production of biofuels and industrial chemicals due to their ability to accumulate high amounts of lipids. In particular, microbial lipids in the form of triacylglycerides (TAGs) produced from renewable feedstocks have attracted considerable attention because they can be directly used in the production of biodiesel and oleochemicals analogous to petrochemicals. As an oleaginous yeast that is generally regarded as safe, Yarrowia lipolytica has been extensively studied, with large amounts of data on its lipid metabolism, genetic tools, and genome sequencing and annotation. In this review, we highlight the newest strategies for increasing lipid accumulation using metabolic engineering and summarize the research advances on the overaccumulation of lipids in Y. lipolytica. Finally, perspectives for future engineering approaches are proposed.
Statins are lipid-lowering therapeutics with favorable anti-inflammatory profiles and have been proposed as an adjunct therapy for COVID-19. However, statins may increase the risk of SARS-CoV-2 viral ...entry by inducing ACE2 expression. Here, we performed a retrospective study on 13,981 patients with COVID-19 in Hubei Province, China, among which 1,219 received statins. Based on a mixed-effect Cox model after propensity score-matching, we found that the risk for 28-day all-cause mortality was 5.2% and 9.4% in the matched statin and non-statin groups, respectively, with an adjusted hazard ratio of 0.58. The statin use-associated lower risk of mortality was also observed in the Cox time-varying model and marginal structural model analysis. These results give support for the completion of ongoing prospective studies and randomized controlled trials involving statin treatment for COVID-19, which are needed to further validate the utility of this class of drugs to combat the mortality of this pandemic.
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•Statin treatment among 13,981 patients with COVID-19 was retrospectively studied•Statin use in this cohort was associated with a lower risk of all-cause mortality•Adding an ACE inhibitor or an ARB did not affect statin-associated outcome in the cohort•The benefit of statins among this cohort may be due to immunomodulatory benefits
Statins have anti-inflammatory benefits and were suggested as an adjunct therapy for COVID-19. But statins may increase the expression of ACE2, the receptor for SARS-CoV-2. Here, Zhang et al. retrospectively analyzed 13,981 COVID-19 cases and found that in-hospital statin use is associated with a lower risk of all-cause mortality.
A practical and efficient method for the direct trifluoromethylthiolation of unactivated C(sp3)H bonds by AgSCF3/K2S2O8 under mild conditions is described. The reaction has a good functional‐group ...tolerance and good selectivity. Initial mechanistic investigations indicate that the reaction may involve a radical process in which K2S2O8 plays key roles in both the activation of the C(sp3)H bond and the oxidation of AgSCF3.
Direct and mild: A variety of alkyltrifluoromethylthioethers were efficiently synthesized by direct trifluoromethylthiolation of unactivated C(sp3)H bonds under mild reaction conditions. The reagent system comprises AgSCF3 and K2S2O8, the latter of which both activates the C(sp3)H bond and oxidizes AgSCF3. The reaction has a broad substrate scope with good functional‐group tolerance and good selectivity.
The interconversion between difluoromethylene ylide and difluorocarbene is described. The difluoromethylene ylide precursor, Ph3P+CF2CO2−, could be turned into an efficient difluorocarbene reagent, ...whereas the classical difluorocarbene reagents, HCF2Cl and FSO2CF2CO2TMS, could generate highly reactive difluoromethylene ylide. Thus the Wittig difluoro‐olefination and difluorocyclopropanation could be selectively realized by using the same reagent. In addition, the ylides obtained from different carbene sources showed different reactivity in Wittig reactions.
Book of ylide: Difluoromethylene phosphonium ylide, generated from Ph3P+CF2CO2−, was turned into an efficient difluorocarbene reagent, whereas the classical difluorocarbene reagents, HCF2Cl and FSO2CF2CO2TMS, generated the highly reactive difluoromethylene ylide. Interestingly, it was found that the ylides obtained from different carbene sources showed different reactivity in Wittig reactions (see scheme; TMS=trimethylsilyl).
Low‐cost multivalent battery chemistries (Mg2+, Al3+) have been extensively investigated for large‐scale energy storage applications. However, their commercialization is plagued by the poor power ...density and cycle life of cathodes. A universal polyimides@CNT (PI@CNT) cathode is now presented that can reversibly store various cations with different valences (Li+, Mg2+, Al3+) at an extremely fast rate. The ion‐coordination charge storage mechanism of PI@CNT is systemically investigated. Full cells using PI@CNT cathodes and corresponding metal anodes exhibit long cycle life (>10000 cycles), fast kinetics (>20 C), and wide operating temperature range (−40 to 50 °C), making the low‐cost industrial polyimides universal cathodes for different multivalent metal batteries. The stable ion‐coordinated mechanism opens a new foundation for the development of high‐energy and high‐power multivalent batteries.
A universal ultrafast organic cathode for multivalent batteries is reported. In contrast to slow solid‐state ion diffusion and phase transformation in inorganic materials with a stiff crystal structure, the soft structure of the PI@CNT composite with the ion‐coordination charge storage mechanism ensures ultrafast reaction kinetics, improving the traditional low power and poor cycle life of multivalent battery chemistries.
Lipids rich in polyunsaturated fatty acids are important nutrients. They are traditionally extracted from animals and plants but alternatively can be obtained from microbes through microbial lipid ...biotechnology. To make this process more economical, apart from strain engineering, the next frontier is through bioprocess and downstream innovation.
Organic compounds are desirable alternatives for sustainable lithium‐ion battery electrodes. However, the electrochemical properties of state‐of‐the‐art organic electrodes are still worse than ...commercial inorganic counterparts. Here, a new chemistry is reported based on the electrochemical conversion of nitro compounds to azo compounds for high performance lithium‐ion batteries. 4‐Nitrobenzoic acid lithium salt (NBALS) is selected as a model nitro compound to systemically investigate the structure, lithiation/delithiation mechanism, and electrochemical performance of nitro compounds. NBALS delivers an initial capacity of 153 mAh g−1 at 0.5 C and retains a capacity of 131 mAh g−1 after 100 cycles. Detailed characterizations demonstrate that during initial electrochemical lithiation, the nitro group in crystalline NBALS is irreversibly reduced into an amorphous azo compound. Subsequently, the azo compound is reversibly lithiated/delithiated in the following charge/discharge cycles with high electrochemical performance. The lithiation/delithiation mechanism of azo compounds is also validated by directly using azo compounds as electrode materials, which exhibit similar electrochemical performance to nitro compounds, while having a much higher initial Coulombic efficiency. Therefore, this work proves that nitro compounds can be electrochemically converted to azo compounds for high performance lithium‐ion batteries.
A new chemistry is unveiled to electrochemically convert nitro compounds into azo compounds, which act as active materials to reversibly react with lithium ions. The discovery of nitro and azo compounds for organic electrodes offers new opportunities for high‐performance lithium‐ion batteries.
Iron fluoride, an intercalation-conversion cathode for lithium ion batteries, promises a high theoretical energy density of 1922 Wh kg
However, poor electrochemical reversibility due to repeated ...breaking/reformation of metal fluoride bonds poses a grand challenge for its practical application. Here we report that both a high reversibility over 1000 cycles and a high capacity of 420 mAh g
can be realized by concerted doping of cobalt and oxygen into iron fluoride. In the doped nanorods, an energy density of ~1000 Wh kg
with a decay rate of 0.03% per cycle is achieved. The anion's and cation's co-substitutions thermodynamically reduce conversion reaction potential and shift the reaction from less-reversible intercalation-conversion reaction in iron fluoride to a highly reversible intercalation-extrusion reaction in doped material. The co-substitution strategy to tune the thermodynamic features of the reactions could be extended to other high energy conversion materials for improved performance.
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