The ornithine-urea cycle involves fumaric acid biosynthesis in Aureobasidium pullulans var.aubasidani,a green and eco-friendly process for fumaric acid production

The current petroleum chemical methods for fumaric acid production can cause heavy pollution and global warming.In this study,the engineered strains of A.pullulans var.aubasidani were found to be suitable for green fumaric acid producer.Removal and complementation of the relevant genes showed only the ornithine-urea cycle(OUC)was involved in high level fumarate biosynthesis which was controlled by the Ca^(2+)signaling pathway.Removal of both the GOX gene encoding glucose oxidase and the PKS1 gene encoding the polyketide synthase for 3,5-dihydroxydecanoic acid biosynthesis and overexpression of the PYC gene encoding pyruvate carboxylase made the strain e-PYC produce 88.1±4.3 g/L of fumarate at flask level and 93.9±0.8 g/L of fumarate during the fed-batch fermentation.As a yeast-like fungal strain,it was very easy to cultivate A.pullulans var.aubasidani DH177 and their mutants in the bioreactor and to edit its genomic DNAs to enhance fumarate production.It was found that 2 mol of CO_(2) could be fixed during a maximal theoretical yield of 2 mol of fumarate per mole of glucose consumed in the OUC.Therefore,the OUC-mediated fumarate biosynthesis pathway in A.pullulans var.aubasidani was a green and eco-friendly process for the global sustainable development and carbon neutrality.

Short-term Prognosis of Fragmented QRS Complex in Patients with Non-ST Elevated Acute Myocardial Infarction

Background：There remains significant debate as to the relationship between fragmented QRS （fQRS） complexes on electrocardiogram （ECG） and acute myocardial infarction （AMI）.Few studies have reported on this relationship in non-ST elevated AMI （NSTEMI）,and thus,we attempt to assess this relationship and its potential short-term prognostic value.Methods：This was a single-center,observational,retrospective cohort study.A total of 513 consecutive patients （399 men,114 women） with NSTEMI within 24 h who underwent coronary angiography at our department,between January 1,2014,and December 31,2014.Patients were divided into 2 groups according to the presence or absence of fQRS complex on the admission ECG.fQRS complexes were defined as the existence of an additional R＇ or crochetage wave,notching in the nadir of the S wave,RS fragmentation,or QS complexes on 2 contiguous leads.All patients were followed up for 6 months,and all major adverse cardiac events （MACE） were recorded.Results：In this study,there were 285 patients with fQRS ECG in the 513 patients with NSTEMI.The number of patients with 0-2 coronary arteries narrowed by ≥50% in fQRS group were less while patients with 3 narrowed arteries were more than in the non-fQRS group （P =0.042）.There were fewer Killip Class Ⅰ patients in the fQRS group （P =0.019）,while Killip Class Ⅱ,Ⅲ,and Ⅳ patients were more in the fQRS group than in the non-fQRS group （P =0.019）.Left ventricular ejection fraction levels were significantly lower in the fQRS group （P =0.021）.Baseline total cholesterol,low-density lipoprotein,creatinine,creatine kinase,homocysteine,high-sensitivity C-reactive protein （CRP）,and red blood cells distribution width levels were significantly higher in the fQRS group.Total MACE （MACE,P =0.028）,revascularization （P =0.005）,and recurrent angina （P =0.005） were also significantly greater in the fQRS group.On final logistic regression analysis,after adjusting for baseline variables,the following variables were independent predictors of fQRS：Coronary artery narrowing （P =0.035）,Killip classification （P =0.026）,and total cholesterol （P =0.002）.The following variables were found to be independent predictors of preoperative MACE：Hemoglobin （P =0.000）,gender （P =0.026）,fQRS （P =0.016）,and time from myocardial infarction to balloon or coronary artery bypasses grafting （P =0.013）.Conclusions：The fQRS complexes are commonly present in NSTEMI and the fQRS complexes are an independent predictor of MACE in NSTEMI patients.The number of narrowed coronary arteries,Killip classification,and total cholesterol are all independent predictors of the fQRS complexes.

Constraints on the Genesis of the Qixiashan Pb-Zn Deposit, Nanjing: Evidence from Sulfide Trace Element Geochemistry

The large-scale Qixiashan Pb-Zn Deposit in the eastern Middle-Lower Yangtze metallogenic belt is hosted in carbonate rocks.Based on a detailed mineral paragenesis study,in-situ LA-ICP-MS(laser ablation inductively coupled plasma mass spectrometer)trace element geochemistry data for pyrite and sphalerite from different stages in the Qixiashan Deposit are reported,the Pb-Zn mineralization processes are reconstructed,and a genetic model is constructed.Four paragenetic stages of Pb-Zn ore deposition are identified:the biogenic pyrite mineralization stage(Stage 1),the early stage of hydrothermal Pb-Zn mineralization(Stage 2),the late stage of hydrothermal Pb-Zn mineralization(Stage 3),and the carbonate stage(Stage 4).Stages 2 and 3 are the main ore stages.The trace element characteristics of the sulfide in stages 2 and 3,such as the higher Co/Ni and lower trace element contents of the pyrite and the Fe,Mn,and Ge contents of the sphalerite,indicate that they were generated by magmatic-hydrothermal processes.Furthermore,the lower Cu,Ag,Sb,and Pb contents of the pyrite and sphalerite of Stage 3 compared to Stage 2 suggest an increase in magmatic-hydrothermal activity from Stage 2 to Stage 3.The hydrothermal fluids leached trace elements(e.g.,Cu,Ag,Sb,and Pb)from the previously deposited primary pyrite and sphalerite,which were precipitated in the later hydrothermal stage Cu,Au,Ag,Sb,and Pb bearing minerals and secondary pyrite and sphalerite with lower trace element contents(e.g.,Cu,Au,Ag,Sb,and Pb).Compared with the pyrite from stages 2 and 3,the Stage 1 pyrite has relatively higher trace elements contents(Sb,Cu,Zn,Au,Ag,Pb,As,and Ni).However,their lower Co/Ni ratio suggests a syngenetic sedimentary origin.Based on the petrographic features and trace element data,a multi-stage mineralization model is proposed.The Stage 1 biogenic pyrite formed stratiform pyrite layers,which provided reducing conditions and a base for the subsequent Pb-Zn mineralization.During Stage 2,subsequent hydrothermal fluid interacted with the stratiform pyrite layers,which resulted in sulfide precipitation and the formation of stratiform Pb-Zn orebodies.In Stage 3,the hydrothermal fluid replaced the limestone along the fractures,which triggered the formation of Pb-Zn vein orebodies.

Efficient production of mannosylerythritol lipids by a marine yeast Moesziomyces aphidis XM01 and their application as self‑assembly nanomicelles

Mannosylerythritol lipids(MELs)are one of the most promising biosurfactants because of their excellent physicochemical properties,high environmental compatibility,and various biological functions.In this study,a mangrove yeast strain Moesziomyces aphidis XM01 was identified and used for efficient extracellular MEL production.The MEL titer reached 64.5±0.7 g/L at flask level within 7 days with the optimized nitrogen and carbon source of 2.0 g/L NaNO_(3) and 70 g/L soybean oil.Furthermore,during a 10-L two-stage fed-batch fermentation,the final MEL titer reached 113.6±3.1 g/L within 8 days,with prominent productivity and yield of 14.2 g·L^(−1)·day^(−1)and 94.6 g/g_((glucose and soybean oil)).Structural analysis indicated that the produced MELs were mainly MEL-A and its fatty acid profile was composed of only medium-chain fatty acids(C8–C12),especially C10 acids(77.81%).Further applications of this compound were evaluated as one-step selfassembly nanomicelles.The obtained MEL nanomicelles showed good physicochemical stability and antibacterial activity.In addition,using clarithromycin as a model hydrophobic drug,the MEL nanomicelles exhibited high loading capacity and could be used for the controlled and sustained drug release in low-pH environments.Therefore,M.aphidis XM01 is an excellent candidate for efficient MEL production,and the prepared MEL nanomicelles have broad application prospects in the pharmaceutical and cosmetic fields.