Diabetes-induced oxidative stress plays a critical role in the mobilisation of endothelial progenitor cells （EPCs） from the bone marrow to the circulation. This study was designed to explore the effects of chronic m...Diabetes-induced oxidative stress plays a critical role in the mobilisation of endothelial progenitor cells （EPCs） from the bone marrow to the circulation. This study was designed to explore the effects of chronic melatonin administration on the promotion of the mobilisation of EPCs and on the preservation of erectile function in type I diabetic rats. Melatonin was administered to streptozotocin-induced type I diabetic rats. EPCs levels were determined using flow cytometry. Oxidative stress in the bone marrow was indicated by the levels of superoxide dismutase and malondialdehyde. Erectile function was evaluated by measuring the intracavernous pressure during an electrostimulation of the cavernous nerve. The density of the endothelium and the proportions of smooth muscle and collagen in the corpus cavernosum were determined by immunohistochemistry. The administration of melatonin increased the superoxide dismutase level and decreased the malondialdehyde level in the bone marrow. This effect was accompanied by an increased level of circulating EPCs in the diabetic rats. The intracavernous pressure to mean arterial pressure ratio of the rats in the treatment group was significantly greater, compared with diabetic control rats. The histological analysis demonstrated an increase in the endothelial density of the corpus cavernosum after the administration of melatonin. However, melatonin treatment did not change the proportions of smooth muscle and collagen in the corpus cavernosum of diabetic rats. Chronic administration of melatonin has a beneficial effect on preventing erectile dysfunction （ED） in type I diabetic rats. Promoting the mobilisation of EPCs is one of the possible mechanisms involved in the improvement of ED.展开更多
Glutaminase is used industrially to enhance flavor and aroma and to enrich foodstuffs nutritionally. It also has potential for pharmaceutical application as anti-leukemia agent. The bacteria of Zymomonas mobilis has b...Glutaminase is used industrially to enhance flavor and aroma and to enrich foodstuffs nutritionally. It also has potential for pharmaceutical application as anti-leukemia agent. The bacteria of Zymomonas mobilis has been studied for ethanol production, however, there is no study regarding glutaminase production. The aim of the present study was to establish the influencing factors for the growth of Z mobilis and its relationship with glutaminase production using statistical tools. Analysis of variance in blocks was carried out in a complete block design and the Tukey test demonstrated the importance of the components of the culture medium, absence of agitation and fermentation time. Minimum culture medium was used in the optimization varying the glucose concentrations （10, 30, and 50 g/L）, glutamine （0, 0.5 and 1g/L） and culture time （18, 24 and 30 hours）. Maximum production was obtained at 8.86 U/L glutaminase. Optimized conditions were used in the growth kinetics, where typical exponential growth was observed. Glutaminase production was shown to be related to biomass production.展开更多
CRISPR-Cas (clustered regularly interspaced short palindromic repeats—CRISPR associated proteins) is a RNA-guided defense immune system that prevents some genetic elements such as plasmids and virus from getting into...CRISPR-Cas (clustered regularly interspaced short palindromic repeats—CRISPR associated proteins) is a RNA-guided defense immune system that prevents some genetic elements such as plasmids and virus from getting into the bacterial cells. Zymomonas mobilis is an ethanologenic bacterium, which encodes a subtype I-F CRISPR-Cas system containing three CRISPR loci and a far distant cas gene cluster. Reverse transcription (RT)-PCR analysis revealed that the CRISPR loci were transcribed on both strands. The Cas proteins were suggested to be expressed based on the previous transcriptomic analysis. Challenging with the invader plasmids containing the artificial protospacer with the protospacer adjacent motif (PAM) of NGG or GG exhibited immune interference activity. However, PAM motif of GG seems more effective than NGG in interference activity. Further, the artificial CRISPR arrays with the spacer sequences targeting to the specific genome sites could also lead to strong immune activity, resulting in almost no transformant grown on the agar plates. It was suggested that bacteria like Z. mobilis ZM4 are lack of the rejoining function to heal the double breakage of genomic DNA made by the CRISPR system. Conclusively, the Type I-F CRISPR-Cas system in Z. mobilis ZM4 is active to functionally defense the invading DNA elements.展开更多
Lactate is an important monomer for the synthesis of poly-lactate(PLA),which is a substitute for the petrochemical plastics.To achieve the goal of high lactate titer,rate,and yield for commercial production,efficient ...Lactate is an important monomer for the synthesis of poly-lactate(PLA),which is a substitute for the petrochemical plastics.To achieve the goal of high lactate titer,rate,and yield for commercial production,efficient lactate production pathway is needed as well as genetic targets that affect high lactate production and tolerance.In this study,an LldR-based d-lactate biosensor with a broad dynamic range was first applied into Zymomonas mobilis to select mutant strains with strong GFP fluorescence,which could be the mutant strains with increased d-lactate production.Then,LldR-based d-lactate biosensor was combined with a genome-wide CRISPR interference(CRISPRi)library targeting the entire genome to generate thousands of mutants with gRNA targeting different genetic targets across the whole genome.Specifically,two mutant libraries were selected containing 105 and 104 mutants with different interference sites from two rounds of fluorescence-activated cell sorting(FACS),respectively.Two genetic targets of ZMO1323 and ZMO1530 were characterized and confirmed to be associated with the increased d-lactate production,further knockout of ZMO1323 and ZMO1530 resulted in a 15%and 21%increase of d-lactate production,respectively.This work thus not only established a high-throughput approach that combines genome-scale CRISPRi and biosensor-assisted screening to identify genetic targets associated with d-lactate production in Z.mobilis,but also provided a feasible high-throughput screening approach for rapid identification of genetic targets associated with strain performance for other industrial microorganisms.展开更多
Due to the complicated metabolic and regulatory networks of l-serine biosynthesis and degradation,microbial cell factories for l-serine production using non-model microorganisms have not been reported.In this study,a ...Due to the complicated metabolic and regulatory networks of l-serine biosynthesis and degradation,microbial cell factories for l-serine production using non-model microorganisms have not been reported.In this study,a combination of synthetic biology and process optimization were applied in an ethanologenic bacterium Zymomonas mobilis for l-serine production.By blocking the degradation pathway while introducing an exporter EceamA from E.coli,l-serine titer in recombinant Z.mobilis was increased from 15.30 mg/L to 62.67 mg/L.It was further increased to 260.33 mg/L after enhancing the l-serine biosynthesis pathway.Then,536.70 mg/L l-serine was achieved by removing feedback inhibition with a SerA mutant,and an elevated titer of 687.67 mg/L was further obtained through increasing serB copies while enhancing the precursors.Finally,855.66 mg/L l-serine can be accumulated with the supplementation of the glutamate precursor.This work thus not only constructed an l-serine producer to help understand the bottlenecks limiting l-serine production in Z.mobilis for further improvement,but also provides guidance on engineering non-model microbes to produce biochemicals with complicated pathways such as amino acids or terpenoids.展开更多
CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against mobile genetic elements(MGEs)through uptake of invader-derived spacers.De novo adaptation samples spacers from both invaders and hosts,whe...CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against mobile genetic elements(MGEs)through uptake of invader-derived spacers.De novo adaptation samples spacers from both invaders and hosts,whereas primed adaptation shows higher specificity to sample spacers from invaders in many model systems as well as in the subtype I-F system of Zymomonas mobilis.Self-derived spacers will lead to CRISPR self-interference.However,our in vivo study demonstrated that this species used the microhomology-mediated end joining(MMEJ)pathway to efficiently repair subtype I-F CRISPR-Cas system-mediated DNA breaks guided by the self-targeting spacers.MMEJ repair of DNA breaks requires direct microhomologous sequences flanking the protospacers and leads to DNA deletions covering the protospacers.Importantly,CRISPR-mediated genomic DNA breaks failed to be repaired via MMEJ pathway in presence of higher copies of short homologous DNA.Moreover,CRISPR-cleaved exogenous plasmid DNA was failed to be repaired through MMEJ pathway,probably due to the inhibition of MMEJ by the presence of higher copies of the plasmid DNA in Z.mobilis.Our results infer that MMEJ pathway discriminates DNA damages between in the host chromosome versus mobile genetic element(MGE)DNA,and maintains genome stability post CRISPR immunity in Z.mobilis.展开更多
High-quality genome-scale metabolic models(GEMs)could play critical roles on rational design of microbial cell factories in the classical Design-Build-Test-Learn cycle of synthetic biology studies.Despite of the const...High-quality genome-scale metabolic models(GEMs)could play critical roles on rational design of microbial cell factories in the classical Design-Build-Test-Learn cycle of synthetic biology studies.Despite of the constant establishment and update of GEMs for model microorganisms such as Escherichia coli and Saccharomyces cerevisiae,high-quality GEMs for non-model industrial microorganisms are still scarce.Zymomonas mobilis subsp.mobilis ZM4 is a non-model ethanologenic microorganism with many excellent industrial characteristics that has been developing as microbial cell factories for biochemical production.Although five GEMs of Z.mobilis have been constructed,these models are either generating ATP incorrectly,or lacking information of plasmid genes,or not providing standard format file.In this study,a high-quality GEM iZM516 of Z.mobilis ZM4 was constructed.The information from the improved genome annotation,literature,datasets of Biolog Phenotype Microarray studies,and recently updated Gene-Protein-Reaction information was combined for the curation of iZM516.Finally,516 genes,1389 reactions,1437 metabolites,and 3 cell compartments are included in iZM516,which also had the highest MEMOTE score of 91%among all published GEMs of Z.mobilis.Cell growth was then predicted by iZM516,which had 79.4%agreement with the experimental results of the substrate utilization.In addition,the potential endogenous succinate synthesis pathway of Z.mobilis ZM4 was proposed through simulation and analysis using iZM516.Furthermore,metabolic engineering strategies to produce succinate and 1,4-butanediol(1,4-BDO)were designed and then simulated under anaerobic condition using iZM516.The results indicated that 1.68 mol/mol succinate and 1.07 mol/mol 1,4-BDO can be achieved through combinational metabolic engineering strategies,which was comparable to that of the model species E.coli.Our study thus not only established a high-quality GEM iZM516 to help understand and design microbial cell factories for economic biochemical production using Z.mobilis as the chassis,but also provided guidance on building accurate GEMs for other non-model industrial microorganisms.展开更多
The decarbonization of the chemical industry and a shift toward circular economies because of high global CO_(2) emissions make CO_(2) an attractive feedstock for manufacturing chemicals.Moreover,H_(2) is a low-cost a...The decarbonization of the chemical industry and a shift toward circular economies because of high global CO_(2) emissions make CO_(2) an attractive feedstock for manufacturing chemicals.Moreover,H_(2) is a low-cost and carbon-free reductant because technologies such as solar-driven electrolysis and supercritical water(scH_(2)O) gasification enable sustainable production of molecular hydrogen(H_(2)).We review the recent advances in engineering Ralsto-nia eutropha,the representative species of“Knallgas”bacteria,for utilizing CO_(2) and H_(2) to autotrophically produce 2,3-butanediol(2,3-BDO).This assessment is focused on state-of-the-art approaches for splitting H_(2) to supply en-ergy in the form of ATP and NADH to power cellular reactions and employing the Calvin-Benson-Bassham cycle for CO_(2) fixation.Major challenges and opportunities for application and future perspectives are discussed in the context of developing other promising CO_(2) and H_(2)-utilizing microorganisms,exemplified by Zymomonas mobilis.展开更多
目的检索并总结青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)患者后路矫形融合术后早期活动的最佳证据,为临床医护人员对患者术后实施早期活动措施提供循证依据。方法按照“6S”证据金字塔模型,采用计算机系统检索UpToDa...目的检索并总结青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)患者后路矫形融合术后早期活动的最佳证据,为临床医护人员对患者术后实施早期活动措施提供循证依据。方法按照“6S”证据金字塔模型,采用计算机系统检索UpToDate,BMJ Best Practice,乔安娜布里格斯研究所(Joanna Briggs Institute,JBI)循证卫生保健中心数据库,美国国立指南数据库,英国国家临床医学研究所指南库,苏格兰院际指南网,Cochrane Library,Medline,PubMed,Embase,中国知网,万方数据库,SinoMed,脊柱侧凸研究学会(Scoliosis Research Society,SRS),美国骨科医师协会骨科相关网站,加速康复外科(enhanced recovery after surgery,ERAS)协会网站关于AIS患者后路矫形融合术后早期活动的临床决策、指南、证据总结、系统评价、随机对照试验研究、类实验研究、专家共识。检索时限为建库至2023年6月30日。由2名研究者独立对文献进行质量评价和资料提取。结果共纳入13篇文献,其中指南1篇、系统评价1篇、随机对照试验5篇、类实验研究1篇、专家共识5篇。从健康宣教、早期功能锻炼的意义及原则、肢体功能锻炼、早期离床、体位适应性训练、安全性评估、终止指标、效果评价8个方面汇总了15条最佳证据。结论本研究总结的AIS患者后路矫形融合术后早期活动的最佳证据可为临床医护人员提供参考,建议在应用证据时结合患者的具体情况制订个性化的活动方案。展开更多
目的:探讨早期康复训练对机械通气重症脑卒中患者功能改善的影响。方法:将50例带有机械通气的重症脑卒中患者按随机字数表法分为试验组和对照组,每组各25例。两组患者均接受神经科ICU常规药物治疗和常规护理,试验组在此基础上进行早期...目的:探讨早期康复训练对机械通气重症脑卒中患者功能改善的影响。方法:将50例带有机械通气的重症脑卒中患者按随机字数表法分为试验组和对照组,每组各25例。两组患者均接受神经科ICU常规药物治疗和常规护理,试验组在此基础上进行早期康复训练,包括肢体运动和呼吸训练,2次/d。比较两组患者治疗前后急性生理与慢性健康状况评分Ⅱ(acute physiology and chronic health evaluation,APACHEⅡ),以及呼吸机相关肺炎(ventilator associated pneumonia,VAP)发生率、撤机成功率、机械通气时间和ICU住院时间。结果:①治疗前两组患者APACHEⅡ评分比较,差异无显著性意义(P>0.05);②治疗后,两组患者APACHEⅡ评分与治疗前比较均明显降低(P<0.01),但组间差异无显著性意义(P>0.05);③治疗后试验组VAP发生率明显低于对照组,而撤机成功率显著高于对照组,机械通气时间和ICU住院时间明显短于对照组(P<0.05)。结论:早期肢体运动和呼吸训练可以提高机械通气重症脑卒中患者的撤机成功率,降低VAP发生率,缩短机械通气时间和ICU住院时间。展开更多
文摘Diabetes-induced oxidative stress plays a critical role in the mobilisation of endothelial progenitor cells （EPCs） from the bone marrow to the circulation. This study was designed to explore the effects of chronic melatonin administration on the promotion of the mobilisation of EPCs and on the preservation of erectile function in type I diabetic rats. Melatonin was administered to streptozotocin-induced type I diabetic rats. EPCs levels were determined using flow cytometry. Oxidative stress in the bone marrow was indicated by the levels of superoxide dismutase and malondialdehyde. Erectile function was evaluated by measuring the intracavernous pressure during an electrostimulation of the cavernous nerve. The density of the endothelium and the proportions of smooth muscle and collagen in the corpus cavernosum were determined by immunohistochemistry. The administration of melatonin increased the superoxide dismutase level and decreased the malondialdehyde level in the bone marrow. This effect was accompanied by an increased level of circulating EPCs in the diabetic rats. The intracavernous pressure to mean arterial pressure ratio of the rats in the treatment group was significantly greater, compared with diabetic control rats. The histological analysis demonstrated an increase in the endothelial density of the corpus cavernosum after the administration of melatonin. However, melatonin treatment did not change the proportions of smooth muscle and collagen in the corpus cavernosum of diabetic rats. Chronic administration of melatonin has a beneficial effect on preventing erectile dysfunction （ED） in type I diabetic rats. Promoting the mobilisation of EPCs is one of the possible mechanisms involved in the improvement of ED.
文摘Glutaminase is used industrially to enhance flavor and aroma and to enrich foodstuffs nutritionally. It also has potential for pharmaceutical application as anti-leukemia agent. The bacteria of Zymomonas mobilis has been studied for ethanol production, however, there is no study regarding glutaminase production. The aim of the present study was to establish the influencing factors for the growth of Z mobilis and its relationship with glutaminase production using statistical tools. Analysis of variance in blocks was carried out in a complete block design and the Tukey test demonstrated the importance of the components of the culture medium, absence of agitation and fermentation time. Minimum culture medium was used in the optimization varying the glucose concentrations （10, 30, and 50 g/L）, glutamine （0, 0.5 and 1g/L） and culture time （18, 24 and 30 hours）. Maximum production was obtained at 8.86 U/L glutaminase. Optimized conditions were used in the growth kinetics, where typical exponential growth was observed. Glutaminase production was shown to be related to biomass production.
文摘CRISPR-Cas (clustered regularly interspaced short palindromic repeats—CRISPR associated proteins) is a RNA-guided defense immune system that prevents some genetic elements such as plasmids and virus from getting into the bacterial cells. Zymomonas mobilis is an ethanologenic bacterium, which encodes a subtype I-F CRISPR-Cas system containing three CRISPR loci and a far distant cas gene cluster. Reverse transcription (RT)-PCR analysis revealed that the CRISPR loci were transcribed on both strands. The Cas proteins were suggested to be expressed based on the previous transcriptomic analysis. Challenging with the invader plasmids containing the artificial protospacer with the protospacer adjacent motif (PAM) of NGG or GG exhibited immune interference activity. However, PAM motif of GG seems more effective than NGG in interference activity. Further, the artificial CRISPR arrays with the spacer sequences targeting to the specific genome sites could also lead to strong immune activity, resulting in almost no transformant grown on the agar plates. It was suggested that bacteria like Z. mobilis ZM4 are lack of the rejoining function to heal the double breakage of genomic DNA made by the CRISPR system. Conclusively, the Type I-F CRISPR-Cas system in Z. mobilis ZM4 is active to functionally defense the invading DNA elements.
基金This work was supported by the National Key Research and Development Program of China(2022YFA0911800)National Natural Science Foundation of China(CN)(21978071)+2 种基金the Key Science and Technology Innovation Project of Hubei Province(2021BAD001)the Innovation Base for Introducing Talents of Discipline of Hubei Province(2019BJH021)We also acknowledge the support from the State Key Laboratory of Biocatalysis and Enzyme Engineering.
文摘Lactate is an important monomer for the synthesis of poly-lactate(PLA),which is a substitute for the petrochemical plastics.To achieve the goal of high lactate titer,rate,and yield for commercial production,efficient lactate production pathway is needed as well as genetic targets that affect high lactate production and tolerance.In this study,an LldR-based d-lactate biosensor with a broad dynamic range was first applied into Zymomonas mobilis to select mutant strains with strong GFP fluorescence,which could be the mutant strains with increased d-lactate production.Then,LldR-based d-lactate biosensor was combined with a genome-wide CRISPR interference(CRISPRi)library targeting the entire genome to generate thousands of mutants with gRNA targeting different genetic targets across the whole genome.Specifically,two mutant libraries were selected containing 105 and 104 mutants with different interference sites from two rounds of fluorescence-activated cell sorting(FACS),respectively.Two genetic targets of ZMO1323 and ZMO1530 were characterized and confirmed to be associated with the increased d-lactate production,further knockout of ZMO1323 and ZMO1530 resulted in a 15%and 21%increase of d-lactate production,respectively.This work thus not only established a high-throughput approach that combines genome-scale CRISPRi and biosensor-assisted screening to identify genetic targets associated with d-lactate production in Z.mobilis,but also provided a feasible high-throughput screening approach for rapid identification of genetic targets associated with strain performance for other industrial microorganisms.
基金This work was supported by the National Key Research and Development Program of China(2022YFA0911800)National Natural Science Foundation of China(CN)(21978071)+2 种基金the Key Science and Technology Innovation Project of Hubei Province(2021BAD001)the Innovation Base for Introducing Talents of Discipline of Hubei Province(2019BJH021)We also acknowledge the support from the State Key Laboratory of Biocatalysis and Enzyme Engineering。
文摘Due to the complicated metabolic and regulatory networks of l-serine biosynthesis and degradation,microbial cell factories for l-serine production using non-model microorganisms have not been reported.In this study,a combination of synthetic biology and process optimization were applied in an ethanologenic bacterium Zymomonas mobilis for l-serine production.By blocking the degradation pathway while introducing an exporter EceamA from E.coli,l-serine titer in recombinant Z.mobilis was increased from 15.30 mg/L to 62.67 mg/L.It was further increased to 260.33 mg/L after enhancing the l-serine biosynthesis pathway.Then,536.70 mg/L l-serine was achieved by removing feedback inhibition with a SerA mutant,and an elevated titer of 687.67 mg/L was further obtained through increasing serB copies while enhancing the precursors.Finally,855.66 mg/L l-serine can be accumulated with the supplementation of the glutamate precursor.This work thus not only constructed an l-serine producer to help understand the bottlenecks limiting l-serine production in Z.mobilis for further improvement,but also provides guidance on engineering non-model microbes to produce biochemicals with complicated pathways such as amino acids or terpenoids.
基金supported by the National Natural Science Foundation of China(31671291 to N.P.,31570055 to M.H.,and 31900400 to T.L.)the Fundamental Research Funds for the Central Universities(2662019PY028 to N.P.)National Natural Science Foundation of China(31900400)。
文摘CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against mobile genetic elements(MGEs)through uptake of invader-derived spacers.De novo adaptation samples spacers from both invaders and hosts,whereas primed adaptation shows higher specificity to sample spacers from invaders in many model systems as well as in the subtype I-F system of Zymomonas mobilis.Self-derived spacers will lead to CRISPR self-interference.However,our in vivo study demonstrated that this species used the microhomology-mediated end joining(MMEJ)pathway to efficiently repair subtype I-F CRISPR-Cas system-mediated DNA breaks guided by the self-targeting spacers.MMEJ repair of DNA breaks requires direct microhomologous sequences flanking the protospacers and leads to DNA deletions covering the protospacers.Importantly,CRISPR-mediated genomic DNA breaks failed to be repaired via MMEJ pathway in presence of higher copies of short homologous DNA.Moreover,CRISPR-cleaved exogenous plasmid DNA was failed to be repaired through MMEJ pathway,probably due to the inhibition of MMEJ by the presence of higher copies of the plasmid DNA in Z.mobilis.Our results infer that MMEJ pathway discriminates DNA damages between in the host chromosome versus mobile genetic element(MGE)DNA,and maintains genome stability post CRISPR immunity in Z.mobilis.
基金the National Key Technology Research and Development Program of China(2018YFA0900300 and 2022YFA0911800)the National Natural Science Foundation of China(21978071 and U1932141)+3 种基金the Key Science and Technology Innovation Project of Hubei Province(2021BAD001)2022 Joint Projects between Chinese and CEEC’s Universities(202004)the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang Province(2018R01014)the Innovation Base for Introducing Talents of Discipline of Hubei Province(2019BJH021)。
文摘High-quality genome-scale metabolic models(GEMs)could play critical roles on rational design of microbial cell factories in the classical Design-Build-Test-Learn cycle of synthetic biology studies.Despite of the constant establishment and update of GEMs for model microorganisms such as Escherichia coli and Saccharomyces cerevisiae,high-quality GEMs for non-model industrial microorganisms are still scarce.Zymomonas mobilis subsp.mobilis ZM4 is a non-model ethanologenic microorganism with many excellent industrial characteristics that has been developing as microbial cell factories for biochemical production.Although five GEMs of Z.mobilis have been constructed,these models are either generating ATP incorrectly,or lacking information of plasmid genes,or not providing standard format file.In this study,a high-quality GEM iZM516 of Z.mobilis ZM4 was constructed.The information from the improved genome annotation,literature,datasets of Biolog Phenotype Microarray studies,and recently updated Gene-Protein-Reaction information was combined for the curation of iZM516.Finally,516 genes,1389 reactions,1437 metabolites,and 3 cell compartments are included in iZM516,which also had the highest MEMOTE score of 91%among all published GEMs of Z.mobilis.Cell growth was then predicted by iZM516,which had 79.4%agreement with the experimental results of the substrate utilization.In addition,the potential endogenous succinate synthesis pathway of Z.mobilis ZM4 was proposed through simulation and analysis using iZM516.Furthermore,metabolic engineering strategies to produce succinate and 1,4-butanediol(1,4-BDO)were designed and then simulated under anaerobic condition using iZM516.The results indicated that 1.68 mol/mol succinate and 1.07 mol/mol 1,4-BDO can be achieved through combinational metabolic engineering strategies,which was comparable to that of the model species E.coli.Our study thus not only established a high-quality GEM iZM516 to help understand and design microbial cell factories for economic biochemical production using Z.mobilis as the chassis,but also provided guidance on building accurate GEMs for other non-model industrial microorganisms.
基金This work was authored by Alliance for Sustainable Energy,LLC,the Manager and Operator of the National Renewable Energy Laboratory for the U.S.Department of Energy(DOE)under Contract No.DE-AC36-08GO28308Funding provided by U.S.Department of Energy Office of Energy Efficiency and Renewable Energy,Bioenergy Technologies Of-fice(BETO)Funding for YJB was provided by the Center for Bioenergy Innovation(CBI),a U.S.Department of Energy Bioenergy Research Cen-ter supported by the Office of Biological and Environmental Research in the DOE Office of Science.
文摘The decarbonization of the chemical industry and a shift toward circular economies because of high global CO_(2) emissions make CO_(2) an attractive feedstock for manufacturing chemicals.Moreover,H_(2) is a low-cost and carbon-free reductant because technologies such as solar-driven electrolysis and supercritical water(scH_(2)O) gasification enable sustainable production of molecular hydrogen(H_(2)).We review the recent advances in engineering Ralsto-nia eutropha,the representative species of“Knallgas”bacteria,for utilizing CO_(2) and H_(2) to autotrophically produce 2,3-butanediol(2,3-BDO).This assessment is focused on state-of-the-art approaches for splitting H_(2) to supply en-ergy in the form of ATP and NADH to power cellular reactions and employing the Calvin-Benson-Bassham cycle for CO_(2) fixation.Major challenges and opportunities for application and future perspectives are discussed in the context of developing other promising CO_(2) and H_(2)-utilizing microorganisms,exemplified by Zymomonas mobilis.
文摘目的检索并总结青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)患者后路矫形融合术后早期活动的最佳证据,为临床医护人员对患者术后实施早期活动措施提供循证依据。方法按照“6S”证据金字塔模型,采用计算机系统检索UpToDate,BMJ Best Practice,乔安娜布里格斯研究所(Joanna Briggs Institute,JBI)循证卫生保健中心数据库,美国国立指南数据库,英国国家临床医学研究所指南库,苏格兰院际指南网,Cochrane Library,Medline,PubMed,Embase,中国知网,万方数据库,SinoMed,脊柱侧凸研究学会(Scoliosis Research Society,SRS),美国骨科医师协会骨科相关网站,加速康复外科(enhanced recovery after surgery,ERAS)协会网站关于AIS患者后路矫形融合术后早期活动的临床决策、指南、证据总结、系统评价、随机对照试验研究、类实验研究、专家共识。检索时限为建库至2023年6月30日。由2名研究者独立对文献进行质量评价和资料提取。结果共纳入13篇文献,其中指南1篇、系统评价1篇、随机对照试验5篇、类实验研究1篇、专家共识5篇。从健康宣教、早期功能锻炼的意义及原则、肢体功能锻炼、早期离床、体位适应性训练、安全性评估、终止指标、效果评价8个方面汇总了15条最佳证据。结论本研究总结的AIS患者后路矫形融合术后早期活动的最佳证据可为临床医护人员提供参考,建议在应用证据时结合患者的具体情况制订个性化的活动方案。
文摘目的:探讨早期康复训练对机械通气重症脑卒中患者功能改善的影响。方法:将50例带有机械通气的重症脑卒中患者按随机字数表法分为试验组和对照组,每组各25例。两组患者均接受神经科ICU常规药物治疗和常规护理,试验组在此基础上进行早期康复训练,包括肢体运动和呼吸训练,2次/d。比较两组患者治疗前后急性生理与慢性健康状况评分Ⅱ(acute physiology and chronic health evaluation,APACHEⅡ),以及呼吸机相关肺炎(ventilator associated pneumonia,VAP)发生率、撤机成功率、机械通气时间和ICU住院时间。结果:①治疗前两组患者APACHEⅡ评分比较,差异无显著性意义(P>0.05);②治疗后,两组患者APACHEⅡ评分与治疗前比较均明显降低(P<0.01),但组间差异无显著性意义(P>0.05);③治疗后试验组VAP发生率明显低于对照组,而撤机成功率显著高于对照组,机械通气时间和ICU住院时间明显短于对照组(P<0.05)。结论:早期肢体运动和呼吸训练可以提高机械通气重症脑卒中患者的撤机成功率,降低VAP发生率,缩短机械通气时间和ICU住院时间。
