The aroma of fragrant rice is one of the grain quality attributes that significantly influenceconsumer preferences and prices in world markets. The volatile compound 2-acetyl-1-pyrroline (2AP) isrecognized as a key co...The aroma of fragrant rice is one of the grain quality attributes that significantly influenceconsumer preferences and prices in world markets. The volatile compound 2-acetyl-1-pyrroline (2AP) isrecognized as a key component of the aroma in fragrant rice. The variation in grain 2AP content amongvarious fragrant rice varieties is associated with the expression of the badh2 gene, with 19 alleles havingbeen identified so far. The grain 2AP content is strongly influenced by environmental and managementfactors during cultivation as well as post-harvest conditions. This review pinpointed the major abiotic andbiotic factors that control grain 2AP content. Abiotic factors refer to water, temperature, light quality,fertilizer application (both macro- and micro-nutrients), and soil properties, including salinity, while bioticfactors include microorganisms that produce aromatic compounds, thus influencing the grain aroma infragrant rice. Post-harvest management, including storage and drying conditions, can significantly impactthe grain 2AP content, and proper post-harvest conditions can intensify the grain aroma. This reviewsuggests that there are rice varieties that can serve as potential sources of genetic material for breedingrice varieties with high grain aroma content. It offers an overview of recent research on the major factorsaffecting the aroma content in fragrant rice. This knowledge will facilitate further research on theproduction of high-quality rice to meet the demands of farmers and consumers.展开更多
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
基金partially funded by the Chiang Mai University (Grant No. RG25/2566)the Thailand Rice Science Research Hub of Knowledge (NRCT: N34E670027), Thailand
文摘The aroma of fragrant rice is one of the grain quality attributes that significantly influenceconsumer preferences and prices in world markets. The volatile compound 2-acetyl-1-pyrroline (2AP) isrecognized as a key component of the aroma in fragrant rice. The variation in grain 2AP content amongvarious fragrant rice varieties is associated with the expression of the badh2 gene, with 19 alleles havingbeen identified so far. The grain 2AP content is strongly influenced by environmental and managementfactors during cultivation as well as post-harvest conditions. This review pinpointed the major abiotic andbiotic factors that control grain 2AP content. Abiotic factors refer to water, temperature, light quality,fertilizer application (both macro- and micro-nutrients), and soil properties, including salinity, while bioticfactors include microorganisms that produce aromatic compounds, thus influencing the grain aroma infragrant rice. Post-harvest management, including storage and drying conditions, can significantly impactthe grain 2AP content, and proper post-harvest conditions can intensify the grain aroma. This reviewsuggests that there are rice varieties that can serve as potential sources of genetic material for breedingrice varieties with high grain aroma content. It offers an overview of recent research on the major factorsaffecting the aroma content in fragrant rice. This knowledge will facilitate further research on theproduction of high-quality rice to meet the demands of farmers and consumers.
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.
