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OBJECTIVES: Ultrasound guidance endoscopic surgery (ES) has been widely used in the treatment of cerebral hemorrhage in recent years, but relevant research articles are still scarce. Our study aims to investigate the effect of ES compared with conventional craniotomy (CC) on the postoperative complications, and prognosis of patients with intracerebral hemorrhage. MATERIALS AND METHODS: The clinical data of 1201 patients with ICH treated in our hospital from January 2017 to January 2020 were collected. The t-test, Chi-squared test and Fisher's exact test were used to analyze the clinical baseline data. Among 1021 spontaneous ICH patients, 193 patients who underwent hematoma evacuation were included in the present analysis. RESULTS: The Glasgow Outcome Scale (GOS) score at 6 months had a favorable prognosis in ES group (p = 0.003). ES group had fewer postoperative complications compared with CC group. Operating time and intraoperative blood loss were significantly lower in ES group than CC group (p = 0.001 and p = 0.002). CONCLUSIONS: Our study revealed that receiving ES improved the prognosis of ICH patients. Additionally, endoscopic surgery diminishes operative time, and intraoperative blood loss and reduces the incidence of postoperative complications.
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Pérdida de Sangre Quirúrgica , Hemorragia Cerebral , Humanos , Estudios Retrospectivos , Resultado del Tratamiento , Hemorragia Cerebral/diagnóstico por imagen , Hemorragia Cerebral/cirugía , Craneotomía/efectos adversos , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Hematoma/diagnóstico por imagen , Hematoma/cirugíaRESUMEN
Beta-elemene, a class of sesquiterpene derived from the Chinese medicinal herb Curcuma wenyujin, is widely used in clinical medicine due to its broad-spectrum antitumor activity. However, the unsustainable plant extraction prompted the search for environmentally friendly strategies for ß-elemene production. In this study, we designed a Yarrowia lipolytica cell factory that can continuously produce germacrene A, which is further converted into ß-elemene with 100% yield through a Cope rearrangement reaction by shifting the temperature to 250°C. First, the productivity of four plant-derived germacrene A synthases was evaluated. After that, the metabolic flux of the precursor to germacrene A was maximized by optimizing the endogenous mevalonate pathway, inhibiting the competing squalene pathway, and expressing germacrene A synthase gene in multiple copies. Finally, the most promising strain achieved the highest ß-elemene titer reported to date with 5.08 g/L. This sustainable and green method has the potential for industrial ß-elemene production.
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Sesquiterpenos , Yarrowia , Extractos Vegetales , Sesquiterpenos/metabolismo , Sesquiterpenos de Germacrano/metabolismo , Yarrowia/metabolismo , Ingeniería MetabólicaRESUMEN
Microbial oils produced by Yarrowia lipolytica offer an environmentally friendly and sustainable alternative to petroleum as well as traditional lipids from animals and plants. The accurate measurement of fermentation parameters, including the substrate concentration, dry cell weight, and lipid accumulation, is the foundation of process control, which is indispensable for industrial lipid production. However, it remains a great challenge to measure the complex parameters online during the lipid fermentation process, which is nonlinear, multivariate, and characterized by strong coupling. As a type of AI technology, the artificial neural network model is a powerful tool for handling extremely complex problems, and it can be employed to develop a soft sensor to monitor the microbial lipid fermentation process of Y. lipolytica. In this study, we first analyzed and emphasized the volume of sodium hydroxide and dissolved oxygen concentration as central parameters of the fermentation process. Then, a soft sensor based on a four-input artificial neural network model was developed, in which the input variables were fermentation time, dissolved oxygen concentration, initial glucose concentration, and additional volume of sodium hydroxide. This provides the possibility of online monitoring of dry cell weight, glucose concentration, and lipid production with high accuracy, which can be extended to similar fermentation processes characterized by the addition of bases or acids, as well as changes of the dissolved oxygen concentration.
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Yarrowia , Animales , Fermentación , Yarrowia/metabolismo , Hidróxido de Sodio/metabolismo , Aceites/metabolismo , Glucosa/metabolismo , Oxígeno/metabolismoRESUMEN
As an optimal one-dimensional reaction coordinate, the committor function not only describes the probability of a trajectory initiated at a phase space point first reaching the product state before reaching the reactant state but also preserves the kinetics when utilized to run a reduced dynamics model. However, calculating the committor function in high-dimensional systems poses significant challenges. In this paper, within the framework of milestoning, exact expressions for committor functions at two levels of coarse graining are given, including committor functions of phase space point to point (CFPP) and milestone to milestone (CFMM). When combined with transition kernels obtained from trajectory analysis, these expressions can be utilized to accurately and efficiently compute the committor functions. Furthermore, based on the calculated committor functions, an adaptive algorithm is developed to gradually refine the transition state region. Finally, two model examples are employed to assess the accuracy of these different formulations of committor functions.
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BACKGROUND: Vancomycin administration is challenging in critically ill patients because of pharmacokinetic changes and requires careful therapeutic drug monitoring (TDM) to guide the appropriate dosing for an effective serum concentration and to avoid toxicity. METHODS: We reported a one-year-old female pediatric patient with a body mass index of 15.4 had successful TDM-guided vancomycin therapy after a living donor liver transplantation for biliary atresia. RESULTS: The patient was admitted to the Intensive Care Unit for sepsis after her second liver transplantation. Even with the administration of the maximum approved vancomycin dosage (40 mg/kg/day), the serum trough levels were less than the recommended therapeutic level. After several adjustments based on TDM, a continuous pump infusion of up to 800 mg/day was needed to reach the desired serum trough concentration of > 10 µg/mL. Sepsis was controlled, and the patient was transferred from the Intensive Care Unit to the general ward and finally discharged home on a regular follow-up plan. CONCLUSIONS: TDM-guided vancomycin continuous infusion may be an effective therapeutic option for pediatric patients after liver transplantation.
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Trasplante de Hígado , Sepsis , Humanos , Niño , Femenino , Lactante , Vancomicina/uso terapéutico , Antibacterianos , Monitoreo de Drogas , Donadores Vivos , Sepsis/tratamiento farmacológico , Sepsis/etiología , Estudios RetrospectivosRESUMEN
The biocatalytic asymmetric reduction of prochiral ketones for the production of enantiopure alcohols is highly desirable due to its inherent advantages over chemical methods. In this study, a new bacterial strain capable of transforming ketones to corresponding alcohols with high activity and excellent enantioselectivity was discovered in a soil sample. The strain was subsequently identified as Bacillus cereus TQ-2 based on its physiological characteristics and 16S rDNA sequence analysis. Under optimized reaction conditions, the resting cells of B. cereus TQ-2 converted acetophenone to enantioenriched (R)-1-phenylethanol with 99% enantiometric excess following anti-Prelog's rule, which is scarce in biocatalytic ketone reduction. The optimum temperature for the cells was 30 °C, and considerable catalytic activity was observed over a broad pH range from 5.0 to 9.0. The cells showed enhanced catalytic activity in the presence of 15% (v/v) glycerol as a co-substrate. The catalytic activity can also be substantially improved by adding Ca2+ or K+ ions. Moreover, the B. cereus TQ-2 cell was highly active in reducing several structurally diverse ketones and aldehydes to form corresponding alcohols with good to excellent conversion. Our study provides a versatile whole-cell biocatalyst that can be used in the asymmetric reduction of ketones for the production of chiral alcohol, thereby expanding the biocatalytic toolbox for potential practical applications.
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Alcoholes , Cetonas , Oxidación-Reducción , Biocatálisis , Etanol , Glicerol , EstereoisomerismoRESUMEN
BACKGROUND: α-Humulene is an important biologically active sesquiterpene, whose heterologous production in microorganisms is a promising alternative biotechnological process to plant extraction and chemical synthesis. In addition, the reduction of production expenses is also an extremely critical factor in the sustainable and industrial production of α-humulene. In order to meet the requirements of industrialization, finding renewable substitute feedstocks such as low cost or waste substrates for terpenoids production remains an area of active research. RESULTS: In this study, we investigated the feasibility of peroxisome-engineering strain to utilize waste cooking oil (WCO) for high production of α-humulene while reducing the cost. Subsequently, transcriptome analysis revealed differences in gene expression levels with different carbon sources. The results showed that single or combination regulations of target genes identified by transcriptome were effective to enhance the α-humulene titer. Finally, the engineered strain could produce 5.9 g/L α-humulene in a 5-L bioreactor. CONCLUSION: To the best of our knowledge, this is the first report that converted WCO to α-humulene in peroxisome-engineering strain. These findings provide valuable insights into the high-level production of α-humulene in Y. lipolytica and its utilization in WCO bioconversion.
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Yarrowia , Yarrowia/metabolismo , Ingeniería Metabólica/métodos , Perfilación de la Expresión Génica , CulinariaRESUMEN
INTRODUCTION: Increased permeability of the renal capillaries is a common consequence of sepsis-associated acute kidney injury. Vascular endothelial (VE)-cadherin is a strictly endothelial-specific adhesion molecule that can control the permeability of the blood vessel wall. Additionally, autophagy plays an important role in maintaining cell stability. Ulinastatin, a urinary trypsin inhibitor, attenuates the systemic inflammatory response and visceral vasopermeability. However, it is uncertain whether ulinastatin can improve renal microcirculation by acting on the endothelial adhesion junction. METHODS: We observed the effect of ulinastatin in a septic rat model using contrast-enhanced ultrasonography (CEUS) to evaluate the perfusion of the renal cortex and medulla. Male adult Sprague Dawley rats were subjected to cecal ligation and puncture and divided into the sham, sepsis, and ulinastatin groups. Ulinastatin (50,000 U/kg) was injected into the tail vein immediately after the operation. The CEUS was performed to evaluate the renal microcirculation perfusion at 3, 6, 12, and 24 h after the operation. Histological staining was used to evaluate kidney injury scores. Western blot was used to quantify the expression of VE-cadherin, LC3II, and inflammatory factors (interleukin-1ß, interleukin-6, and tumor necrosis factor-α) in kidney tissue, and enzyme-linked immunosorbent assay detected serum inflammatory factors and kidney function and early kidney injury biomarker levels. RESULTS: Compared with the sham group, ulinastatin reduced the inflammatory response, inhibited autophagy, maintained the expression of VE-cadherin, and meliorated cortical and medullary perfusion. CONCLUSION: Ulinastatin effectively protects the adhesion junction and helps ameliorate the perfusion of kidney capillaries during sepsis by the inhibition of autophagy and the expression of inflammatory factors.
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Células Endoteliales , Sepsis , Animales , Autofagia , Glicoproteínas , Riñón , Masculino , Microcirculación , Ratas , Ratas Sprague-Dawley , Sepsis/tratamiento farmacológicoRESUMEN
Rhein is an active component from Chinese herbal medicine. It can cause diarrhea by inhibiting Na+ , K+ -ATPase activity on intestinal epithelial cells, thus decreasing the re-absorption of Na+ from intestinal tract to blood. However, when this Na+ , K+ -ATPase inhibition was quantitated by a colorimetric method that measures ATPase-catalyzed release of inorganic phosphorus, the data obtained were inconsistent and showed great variation. We developed a novel method using inductively coupled plasma mass spectrometry (ICP-MS) to quantitate the amount of intracellular Rb+ . This method largely mimics the 86 RbCl tracer flux assay, but it uses non-radioactive RbCl as a flux substrate. The results demonstrated that this method has better precision and accuracy than the conventional colorimetric method. More importantly, this method is free from radioactive substances, which is expected to make it safer and more convenient than the radioactive 86 RbCl tracer flux method. In conclusion, the ICP-MS method for Na+ , K+ -ATPase activity determination is novel and accurate. It can also provide a reference for studying the transport of other metal ions across membranes under biological conditions.
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Antraquinonas/farmacología , Espectrometría de Masas/métodos , ATPasa Intercambiadora de Sodio-Potasio , Cloruros , Colorimetría , Células HCT116 , Humanos , Límite de Detección , Reproducibilidad de los Resultados , Rubidio , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , ATPasa Intercambiadora de Sodio-Potasio/metabolismoRESUMEN
Renal interstitial fibrosis (RIF) is a common pathological characteristic associated with end-stage renal disease. However, treatment strategies for RIF are still very limited. In this study, we reported that kaempferol, a classic flavonoid, exhibited strong and widely inhibitory effect on the expression of fibrosis related genes in transforming growth factor beta 1 (TGF-ß1) treated NRK-52E cells. Further studies revealed that kaempferol inhibited TGF-ß1 induced epithelial-mesenchymal transition (EMT) process of NRK-52E cells and improved renal function deterioration and RIF in unilateral ureteral obstruction (UUO) rats. After exploring the underlying mechanisms, we found that kaempferol was able to activate the BMP-7-Smad1/5 pathway, rather than the TGF-ß1-Smad2/3 pathway. To further validate these results, DMH1 and BMP-7 knockdown were utilized at the cellular level and the results showed that both methods were able to antagonize the effects of kaempferol on the EMT process of NRK-52E cells induced by TGF-ß1. In UUO rats, inhibition of BMP-7 signaling by DMH1 also reversed the effects of kaempferol on renal function decline and RIF. Taken together, our findings demonstrated that kaempferol could be a good candidate for renal fibrosis treatment.
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Proteína Morfogenética Ósea 7/metabolismo , Quempferoles/farmacología , Enfermedades Renales/metabolismo , Proteínas Smad Reguladas por Receptores/metabolismo , Proteína Smad1/metabolismo , Proteína Smad5/metabolismo , Animales , Línea Celular , Colágeno/metabolismo , Células Epiteliales , Fibrosis , Riñón/efectos de los fármacos , Riñón/patología , Masculino , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
This 1:5 case-control study aimed to identify the risk factors of hospital-acquired pressure injuries (HAPIs) and to develop a mathematical model of nomogram for the risk prediction of HAPIs. Data for 370 patients with HAPIs and 1971 patients without HAPIs were extracted from the adverse events and the electronic medical systems. They were randomly divided into two sets: training (n = 1951) and validation (n = 390). Significant risk factors were identified by univariate and multivariate analyses in the training set, followed by a nomogram constructed. Age, independent movement, sensory perception and response, moisture, perfusion, use of medical devices, compulsive position, hypoalbuminaemia, an existing pressure injury or scarring from a previous pressure injury, and surgery sufferings were considered significant risk factors and were included to construct a nomogram. In both of the training and validation sets, the areas of 0.90 under the receiver operating characteristic curves showed excellent discrimination of the nomogram; calibration plots demonstrated a good consistency between the observed probability and the nomogram's prediction; decision curve analyses exhibited preferable net benefit along with the threshold probability in the nomogram. The excellent performance of the nomogram makes it a convenient and reliable tool for the risk prediction of HAPIs.
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Predicción/métodos , Enfermedad Iatrogénica , Nomogramas , Úlcera por Presión/etiología , Presión/efectos adversos , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Teóricos , Reproducibilidad de los Resultados , Factores de RiesgoRESUMEN
BACKGROUND: Ticagrelor and clopidogrel, P2Y12 receptor antagonists, can prevent thrombotic events and are used to treat cardiovascular diseases such as acute coronary syndrome and chronic obstructive pulmonary disease, in which inflammation is involved. Moreover, NF-B is the central regulator of inflammation. Thus, we suspected that ticagrelor and clopidogrel are involved in the regulation of the NF-ΚB signaling pathway. METHODS: After human umbilical vein endothelial cells (HUVECs) were cultured with ticagrelor or clopidogrel and given lipopolysaccharide (LPS) and CD14, the mRNA levels of related inflammatory factors, the protein level and subcellular localization of molecules in the NF-ΚB signaling pathway, cell viability, apoptosis and the cell cycle, cell migration, and vascular formation were detected using quantitative polymerase chain reaction (qPCR), western blotting and immunofluorescence assay, CCK-8, flow cytometry, transwell assay, and matrigel, respectively. All data was expressed as the mean ± S.D. The statistical significance of data was assessed by an unpaired two-tailed t-test. RESULTS: Ticagrelor and clopidogrel can inhibit the degradation of IKBα and phosphorylation of p65, prevent p65 from entering the nucleus, reduce the production of TNFα, IL-1, IL-8, IL-6 and IL-2, and alleviate the decrease in cell viability, cell migration and angiogenesis, the changes of cell cycle and apoptosis induced by LPS. CONCLUSIONS: Ticagrelor and clopidogrel alleviate cellular dysfunction through suppressing NF-ΚB signaling pathway.
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Antiinflamatorios/farmacología , Clopidogrel/farmacología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Lipopolisacáridos/toxicidad , FN-kappa B/metabolismo , Antagonistas del Receptor Purinérgico P2Y/farmacología , Ticagrelor/farmacología , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Citocinas/metabolismo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Células Endoteliales de la Vena Umbilical Humana/patología , Humanos , Quinasa I-kappa B/metabolismo , Neovascularización Fisiológica/efectos de los fármacos , Fosforilación , Transducción de Señal , Factor de Transcripción ReIA/metabolismoRESUMEN
In recent years, eukaryotic microorganisms have been widely applied to offer many solutions for everyday life and have come to play important roles in agriculture, food, health care, and the fine-chemicals industry. However, the complex genetic background and low homologous recombination efficiency have hampered the implementation of large-scale and high-throughput gene editing in many eukaryotic microorganisms. The low efficiency of homologous recombination (HR) not only makes the modification process labor-intensive but also completely precludes the application of many otherwise very useful genome editing techniques. Thus, increasing the efficiency of HR is clearly an enabling technology for basic research and gene editing in eukaryotic microorganisms. In this review, we summarize the current strategies for enhancing the efficiency of HR in eukaryotic microorganisms (particularly yeasts and filamentous fungi), list some small molecules and candidate genes associated with homologous and non-homologous recombination, and briefly discuss the further development prospects of these strategies.
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Hongos/genética , Edición Génica/métodos , Recombinación Homóloga , Ingeniería Metabólica/métodos , Levaduras/genéticaRESUMEN
Pneumocandin B0 is a hydrophobic secondary metabolite that accumulates in the mycelia of Glarea lozoyensis and inhibits fungal 1,3-ß-glucan synthase. Extractive batch fermentation can promote the release of intracellular secondary metabolites into the fermentation broth and is often used in industry. The addition of extractants has been proven as an effective method to attain higher accumulation of hydrophobic secondary metabolites and circumvent troublesome solvent extraction. Various extractants exerted significant but different influences on the biomass and pneumocandin B0 yields. The maximum pneumocandin B0 yield (2528.67 mg/L) and highest extracellular pneumocandin B0 yield (580.33 mg/L) were achieved when 1.0 g/L SDS was added on the 13th day of extractive batch fermentation, corresponding to significant increases of 37.63 and 154% compared with the conventional batch fermentation, respectively. The mechanism behind this phenomenon is partly attributed to the release of intracellular pneumocandin B0 into the fermentation broth and the enhanced biosynthesis of pneumocandin B0 in the mycelia.
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Ascomicetos/efectos de los fármacos , Ascomicetos/metabolismo , Equinocandinas/aislamiento & purificación , Equinocandinas/metabolismo , Dodecil Sulfato de Sodio/metabolismo , Tensoactivos/metabolismo , Medios de Cultivo/química , FermentaciónRESUMEN
The ω-3/long-chain polyunsaturated fatty acids (LC-PUFAs) play an important role in human health, but they cannot be synthesized in sufficient amounts by the human body. In a previous study, we obtained an engineered Schizochytrium sp. strain (HX-RS) by exchanging the acyltransferase (AT) gene, and it was able to co-produce docosahexaenoic acid and eicosapentaenoic acid. To investigate the mechanism underlying the increase of PUFA content in HX-RS, the discrepancies of fermentation performance, key enzyme activities and intracellular metabolites between HX-RS and its wild-type parent strain (WTS) were analyzed via fed-batch fermentation in 5-L bioreactors. The results showed that the cell dry weight (CDW) of HX-RS was higher than that of the WTS. Metabolomics combined with multivariate analysis showed that 4-aminobutyric acid, proline and glutamine are potential biomarkers associated with cell growth and lipid accumulation of HX-RS. Additionally, the shift of metabolic flux including a decrease of glyceraldehyde-3-phosphate content, high flux from pyruvate to acetyl-CoA, and a highly active glycolysis pathway were also found to be closely related to the high PUFA yield of the engineered strain. These findings provide new insights into the effects of exogenous AT gene expression on cell proliferation and fatty acid metabolism.
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Ácidos Grasos Insaturados/química , Fermentación , Estramenopilos/metabolismo , Bioingeniería/métodos , Biomarcadores/metabolismo , Reactores Biológicos , Biotecnología/métodos , Proliferación Celular , Ácidos Docosahexaenoicos/metabolismo , Ácido Eicosapentaenoico/análogos & derivados , Ácido Eicosapentaenoico/metabolismo , Ácidos Grasos Omega-3/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Glucosa/química , Glutamina/química , Metabolismo de los Lípidos , Lípidos/química , Metabolómica , Análisis Multivariante , Prolina/química , Ácido gamma-Aminobutírico/químicaRESUMEN
The oleaginous yeast Yarrowia lipolytica is widely used for the production of both bulk and fine chemicals, including organic acids, fatty acid-derived biofuels and chemicals, polyunsaturated fatty acids, single-cell proteins, terpenoids, and other valuable products. Consequently, it is becoming increasingly popular for metabolic engineering applications. Multiple gene manipulation tools including URA blast, Cre/LoxP, and transcription activator-like effector nucleases (TALENs) have been developed for metabolic engineering in Y. lipolytica. However, the low efficiency and time-consuming procedures involved in these methods hamper further research. The emergence of the CRISPR/Cas system offers a potential solution for these problems due to its high efficiency, ease of operation, and time savings, which can significantly accelerate the genomic engineering of Y. lipolytica. In this review, we summarize the research progress on the development of CRISPR/Cas systems for Y. lipolytica, including Cas9 proteins and sgRNA expression strategies, as well as gene knock-out/knock-in and repression/activation applications. Finally, the most promising and tantalizing future prospects in this area are highlighted.
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Ingeniería Metabólica/métodos , Yarrowia/genética , Yarrowia/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Sistemas CRISPR-Cas , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Ingeniería Metabólica/tendenciasRESUMEN
Pneumocandin B0, the precursor of the antifungal drug caspofungin, is a secondary metabolite of the fungus Glarea lozoyensis. In this study, we investigated the effects of mannitol as the sole carbon source on pneumocandin B0 production by G. lozoyensis. The osmotic pressure is more important in enhancing pneumocandin B0 production than is the substrate concentration. Based on the kinetic analysis, an osmotic stress control fed-batch strategy was developed. This strategy led to a maximum pneumocandin B0 concentration of 2711 mg/L with a productivity of 9.05 mg/L/h, representing 34.67 and 6.47% improvements, respectively, over the best result achieved by the one-stage fermentation. Furthermore, G. lozoyensis accumulated glutamate and proline as compatible solutes to resist osmotic stress, and these amino acids also provided the precursors for the enhanced pneumocandin B0 production. Osmotic stress also activated ROS (reactive oxygen species)-dependent signal transduction by upregulating the levels of related genes and increasing intracellular ROS levels by 20%. We also provided a possible mechanism for pneumocandin B0 accumulation based on signal transduction. These findings will improve our understanding of the regulatory mechanisms of pneumocandin B0 biosynthesis and may be applied to improve secondary metabolite production.
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Ascomicetos/genética , Ascomicetos/metabolismo , Equinocandinas/metabolismo , Presión Osmótica/fisiología , Antioxidantes/metabolismo , Ascomicetos/efectos de los fármacos , Ascomicetos/crecimiento & desarrollo , Carbono/metabolismo , Enzimas/genética , Enzimas/metabolismo , Fermentación , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Manitol/metabolismo , Manitol/farmacología , Transducción de Señal/genéticaRESUMEN
Metabolic profiling was used to discover mechanisms of increased pneumocandin B0 production in a high-yield strain by comparing it with its parent strain. Initially, 79 intracellular metabolites were identified, and the levels of 15 metabolites involved in six pathways were found to be directly correlated with pneumocandin B0 biosynthesis. Then by combining the analysis of key enzymes, acetyl-CoA and NADPH were identified as the main factors limiting pneumocandin B0 biosynthesis. Other metabolites, such as pyruvate, α-ketoglutaric acid, lactate, unsaturated fatty acids and previously unreported metabolite γ-aminobutyric acid were shown to play important roles in pneumocandin B0 biosynthesis and cell growth. Finally, the overall metabolic mechanism hypothesis was formulated and a rational feeding strategy was implemented that increased the pneumocandin B0 yield from 1821 to 2768 mg/L. These results provide practical and theoretical guidance for strain selection, medium optimization, and genetic engineering for pneumocandin B0 production.
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Acetilcoenzima A/metabolismo , Ascomicetos/genética , Equinocandinas/genética , Equinocandinas/metabolismo , Glucosa/química , Metabolómica , Aminoácidos/química , Antifúngicos/química , Biomasa , Ciclo del Ácido Cítrico , Ácidos Grasos/química , Ácidos Grasos Insaturados/química , Ingeniería Genética , Microbiología Industrial , Ácidos Cetoglutáricos/química , Ácido Láctico/química , Manitol/química , Modelos Teóricos , NADP/química , Vía de Pentosa Fosfato , Ácido Pirúvico/químicaRESUMEN
In recent years, a variety of genetic tools have been developed and applied to various filamentous fungi, which are widely applied in agriculture and the food industry. However, the low efficiency of gene targeting has for many years hampered studies on functional genomics in this important group of microorganisms. The emergence of CRISPR/Cas9 genome-editing technology has sparked a revolution in genetic research due to its high efficiency, versatility, and easy operation and opened the door for the discovery and exploitation of many new natural products. Although the application of the CRISPR/Cas9 system in filamentous fungi is still in its infancy compared to its common use in E. coli, yeasts, and mammals, the deep development of this system will certainly drive the exploitation of fungal diversity. In this review, we summarize the research progress on CRISPR/Cas9 systems in filamentous fungi and finally highlight further prospects in this area.
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Sistemas CRISPR-Cas , Hongos/genética , Edición Génica/métodos , Genoma Fúngico , Microbiología Industrial/métodos , Agricultura/métodos , Industria de Alimentos/métodosRESUMEN
To investigate the metabolic regulation against oxygen supply, comparative metabolomics was performed to explore the metabolic responses of Mortierella alpina in the process of arachidonic acid (ARA) production. More than 110 metabolites involved in Embden-Meyerhof-Parnas pathway, pentose phosphate pathway, tricarboxylic acid cycle, inositol phosphate metabolism, fatty acid biosynthesis, and amino acid metabolism were identified by gas chromatography-mass spectrometry. Samples at different aeration rates were clearly distinguished by principal components analysis and partial least squares analysis, indicating that oxygen supply had a profound effect on the metabolism of M. alpina. Eleven major metabolites were identified as potential biomarkers to be primarily responsible for the difference of metabolism. Further study of metabolic changes with the relevant pathways demonstrated that the levels of several intermediate metabolites in relation to central carbon metabolism changed remarkably via both processes and citrate and malate was supposed to play vital roles in polyunsaturated acid (PUFA) synthesis. Increase of myo-inositol and sorbitol were probably for osmo-regulation and redox balance, while enhanced phosphoric acid and pyroglutamic acid were supposed to have function in the activation of signal transduction pathway for stress resistance. The present study provides a novel insight into the metabolic responses of M. alpina to aeration rates and the metabolic characteristics during the ARA fermentation.