Defining suitable enzymes for reaction steps in novel synthetic pathways is crucial for developing microbial cell factories for non-natural products.Here,we developed a computational workflow to identify C12 alcohol-a...Defining suitable enzymes for reaction steps in novel synthetic pathways is crucial for developing microbial cell factories for non-natural products.Here,we developed a computational workflow to identify C12 alcohol-active UDP-glycosyltransferases.The workflow involved three steps:(1)assembling initial candidates of putative UDP-glycosyltransferases,(2)refining selection by examining conserved regions,and(3)3D structure prediction and molecular docking.Genomic sequences from Candida,Pichia,Rhizopus,and Thermotoga,known for lauryl glucoside synthesis via whole-cell biocatalysis,were screened.Out of 240 predicted glycosyltransferases,8 candidates annotated as glycosyltransferases were selected after filtering out those with signal peptides and identifying conserved UDP-glycosyltransferase regions.These proteins underwent 3D structure prediction and molecular docking with 1-dodecanol.RO3G,a candidate from Rhizopus delemar RA 99-880 with a relatively high ChemPLP fitness score,was selected and expressed in Escherichia coli BL21(DE3).It was further characterized using a feeding experiment with 1-dodecanol.Results confirmed that the RO3G-expressing strain could convert 1-dodecanol to lauryl glucoside,as quantified by HPLC and identified by targeted LC-MS.Monitoring the growth and fermentation profiles of the engineered strain revealed that RO3G expression did not affect cell growth.Interestingly,acetate,a major fermentation product,was reduced in the RO3G-expressing strain compared to the GFP-expressing strain,suggesting a redirection of flux from acetate to other pathways.Overall,this work presents a successful workflow for discovering UDP-glycosyltransferase enzymes with confirmed activity toward 1-dodecanol for lauryl glucoside production.展开更多
With the purpose of efficiently predicting structural radiated noise of internal combustion engine（I.C.E.）,a new simulation technique is introduced,which is an approach based on boundary element method （BEM）,acous...With the purpose of efficiently predicting structural radiated noise of internal combustion engine（I.C.E.）,a new simulation technique is introduced,which is an approach based on boundary element method （BEM）,acoustic transfer vector（ATV） technique and coupled boundary element model and finite element model （BEM-FEM） approach.Analyses of vibration exciting loads,computing structural dynamic characteristics and dynamic responses have led to theoretical results,which are tested on an L6 diesel engine to validate this proposed technique in engineering practice.展开更多
The Beijing Diesel Engine Group Corporation I/E Co. is a subsidiary company under the Beijing Diesel Engine Group Corporation (BDEGC), a foreign window for the enterprise. The BDEGC is the nation’s largest specialize...The Beijing Diesel Engine Group Corporation I/E Co. is a subsidiary company under the Beijing Diesel Engine Group Corporation (BDEGC), a foreign window for the enterprise. The BDEGC is the nation’s largest specialized diesel engine production factory, a super large enterprise at state level. Its main products include six series of motors and the 1040 series light trucks, 6400 and 6401 wagon cars, agricultural self-discharging semitrailers, and light-duty pilothouses and covers. The power of annual diesel engine output has reached 40 million KW, with the products’ coverage rate on the market ranking in a leading position among the same trade nationwide. Since the 1980s, the BDEGC has exported indefinite quantities of展开更多
Background： A comprehensive metabolism network of engineered E. coli is very important in systems biology and metabolomics studies. Many tools focus on two-dimensional space to display pathways in metabolic network. ...Background： A comprehensive metabolism network of engineered E. coli is very important in systems biology and metabolomics studies. Many tools focus on two-dimensional space to display pathways in metabolic network. However, the usage of three-dimensional visualization may help to understand better the intricate topology of metabolic and regulatory networks. Methods： We manually curated large amount of experimental data （including pathways, reactions and metabolites） from literature related with different types of engineered E. coli and then utilized a novel technology of three dimensional visualization to develop a comprehensive metabolic network named SynBioEcoll. Results： SynBioEoli contains 740 biosynthetic pathways, 3,889 metabolic reactions, 2,255 chemical compounds manually curated from about 11,000 metabolism publications related with different types of engineered E. coil Furthermore, SynBioEcoli integrates with various informatics techniques. Conclusions： SynBioEcoli could be regarded as a comprehensive knowledgebase of engineered E. coli and represents the next generation cellular metabolism network visualization technology. It could be accessed via web browsers （such as Google Chrome） supporting WebGL, at http：//www.rxnfinder.org/synbioecoli/.展开更多
基金This work(Grant No.RGNS 64-069)was financially supported by Office of the Permanent Secretary,Ministry of Higher Education,Science,Research and Innovationpartially supported by Chiang Mai University.
文摘Defining suitable enzymes for reaction steps in novel synthetic pathways is crucial for developing microbial cell factories for non-natural products.Here,we developed a computational workflow to identify C12 alcohol-active UDP-glycosyltransferases.The workflow involved three steps:(1)assembling initial candidates of putative UDP-glycosyltransferases,(2)refining selection by examining conserved regions,and(3)3D structure prediction and molecular docking.Genomic sequences from Candida,Pichia,Rhizopus,and Thermotoga,known for lauryl glucoside synthesis via whole-cell biocatalysis,were screened.Out of 240 predicted glycosyltransferases,8 candidates annotated as glycosyltransferases were selected after filtering out those with signal peptides and identifying conserved UDP-glycosyltransferase regions.These proteins underwent 3D structure prediction and molecular docking with 1-dodecanol.RO3G,a candidate from Rhizopus delemar RA 99-880 with a relatively high ChemPLP fitness score,was selected and expressed in Escherichia coli BL21(DE3).It was further characterized using a feeding experiment with 1-dodecanol.Results confirmed that the RO3G-expressing strain could convert 1-dodecanol to lauryl glucoside,as quantified by HPLC and identified by targeted LC-MS.Monitoring the growth and fermentation profiles of the engineered strain revealed that RO3G expression did not affect cell growth.Interestingly,acetate,a major fermentation product,was reduced in the RO3G-expressing strain compared to the GFP-expressing strain,suggesting a redirection of flux from acetate to other pathways.Overall,this work presents a successful workflow for discovering UDP-glycosyltransferase enzymes with confirmed activity toward 1-dodecanol for lauryl glucoside production.
基金Sponsored by the National Natural Science Foundation of China (50505047)Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi
文摘With the purpose of efficiently predicting structural radiated noise of internal combustion engine（I.C.E.）,a new simulation technique is introduced,which is an approach based on boundary element method （BEM）,acoustic transfer vector（ATV） technique and coupled boundary element model and finite element model （BEM-FEM） approach.Analyses of vibration exciting loads,computing structural dynamic characteristics and dynamic responses have led to theoretical results,which are tested on an L6 diesel engine to validate this proposed technique in engineering practice.
文摘The Beijing Diesel Engine Group Corporation I/E Co. is a subsidiary company under the Beijing Diesel Engine Group Corporation (BDEGC), a foreign window for the enterprise. The BDEGC is the nation’s largest specialized diesel engine production factory, a super large enterprise at state level. Its main products include six series of motors and the 1040 series light trucks, 6400 and 6401 wagon cars, agricultural self-discharging semitrailers, and light-duty pilothouses and covers. The power of annual diesel engine output has reached 40 million KW, with the products’ coverage rate on the market ranking in a leading position among the same trade nationwide. Since the 1980s, the BDEGC has exported indefinite quantities of
基金This work was supported by the National Science Foundation of China （Nos. 31270101 and 31570092）, the National High Technology Research and Development Program （No. 2012CB721000） and the Natural Science Foundation of Tianjin, China.
文摘Background： A comprehensive metabolism network of engineered E. coli is very important in systems biology and metabolomics studies. Many tools focus on two-dimensional space to display pathways in metabolic network. However, the usage of three-dimensional visualization may help to understand better the intricate topology of metabolic and regulatory networks. Methods： We manually curated large amount of experimental data （including pathways, reactions and metabolites） from literature related with different types of engineered E. coli and then utilized a novel technology of three dimensional visualization to develop a comprehensive metabolic network named SynBioEcoll. Results： SynBioEoli contains 740 biosynthetic pathways, 3,889 metabolic reactions, 2,255 chemical compounds manually curated from about 11,000 metabolism publications related with different types of engineered E. coil Furthermore, SynBioEcoli integrates with various informatics techniques. Conclusions： SynBioEcoli could be regarded as a comprehensive knowledgebase of engineered E. coli and represents the next generation cellular metabolism network visualization technology. It could be accessed via web browsers （such as Google Chrome） supporting WebGL, at http：//www.rxnfinder.org/synbioecoli/.
