DNA molecules are green materials with great potential for high-density and long-term data storage.However,the current data-writing process of DNA data storage via DNA synthesis suffers from high costs and the product...DNA molecules are green materials with great potential for high-density and long-term data storage.However,the current data-writing process of DNA data storage via DNA synthesis suffers from high costs and the production of hazards,limiting its practical applications.Here,we developed a DNA movable-type storage system that can utilize DNA fragments pre-produced by cell factories for data writing.In this system,these pre-generated DNA fragments,referred to herein as“DNA movable types,”are used as basic writing units in a repetitive way.The process of data writing is achieved by the rapid assembly of these DNA movable types,thereby avoiding the costly and environmentally hazardous process of de novo DNA synthesis.With this system,we successfully encoded 24 bytes of digital information in DNA and read it back accurately by means of high-throughput sequencing and decoding,thereby demonstrating the feasibility of this system.Through its repetitive usage and biological assembly of DNA movable-type fragments,this system exhibits excellent potential for writing cost reduction,opening up a novel route toward an economical and sustainable digital data-storage technology.展开更多
Polymyxin B,produced by Paenibacillus polymyxa,is used as the last line of defense clinically.In this study,exogenous mixture of precursor amino acids increased the level and proportion of polymyxin B1 in the total of...Polymyxin B,produced by Paenibacillus polymyxa,is used as the last line of defense clinically.In this study,exogenous mixture of precursor amino acids increased the level and proportion of polymyxin B1 in the total of polymyxin B analogs of P.polymyxa CJX518-AC(PPAC)from 0.15 g/L and 61.8%to 0.33 g/L and 79.9%,respectively.The co-culture of strain PPAC and recombinant Corynebacterium glutamicum-leu01,which produces high levels of threonine,leucine,and isoleucine,increased polymyxin B1 production to 0.64 g/L.When strains PPAC and C.glu-leu01 simultaneously inoculated into an optimized medium with 20 g/L peptone,polymyxin B1 production was increased to 0.97 g/L.Furthermore,the polymyxin B1 production in the co-culture of strains PPAC and C.glu-leu01 increased to 2.21 g/L after optimized inoculation ratios and fermentation medium with 60 g/L peptone.This study provides a new strategy to improve polymyxin B1 production.展开更多
Genomic rearrangements play a crucial role in shaping biological phenotypic diversity and driving species evolution.Synthetic chromosome rearrangement and modification by LoxP-mediated evolution(SCRaMbLE)has been appl...Genomic rearrangements play a crucial role in shaping biological phenotypic diversity and driving species evolution.Synthetic chromosome rearrangement and modification by LoxP-mediated evolution(SCRaMbLE)has been applied to explore large-scale genomic rearrangements,yet it has been observed that these rearrangements occur exclusively in genomic regions containing loxPsym sites.Here,we found that SCRaMbLE of synthetic yeast harboring synthetic chromosome V and X can generate a variety of synthetic segment insertions into wild-type chromosomes,ranging from 1 to 300 kb.Furthermore,it was revealed that the novel insertions impacted the transcriptional level of neighboring regions and affected the production of exemplar pathway of zeaxanthin.Collectively,our results improve the understanding of the ability of SCRaMbLE to generate complex structural variations in nonsynthetic regions and provide a potential model to explore genomic transposable events.展开更多
Genomic rearrangements play a significant role in disease,evolution,and tumorigenesis(Mani and Chinnaiyan,2010).While single nucleotide polymorphisms(SNPs)and small insertions/deletions contribute substantially to gen...Genomic rearrangements play a significant role in disease,evolution,and tumorigenesis(Mani and Chinnaiyan,2010).While single nucleotide polymorphisms(SNPs)and small insertions/deletions contribute substantially to genetic variation,discerning the independent impact of structural variations poses a challenge.展开更多
catalyzed byβ-carotene hydroxylase(crtZ)andβ-carotene ketolase(crtW)decreases the content of the astaxanthin.Here,we exploited directed evolution of the fusion of crtZ and crtW for improving astaxanthin biosynthesis...catalyzed byβ-carotene hydroxylase(crtZ)andβ-carotene ketolase(crtW)decreases the content of the astaxanthin.Here,we exploited directed evolution of the fusion of crtZ and crtW for improving astaxanthin biosynthesis in Saccharomyces cerevisiae.The results demonstrated that the fusion enzyme of crtZ-crtW with 2 X GGGGS peptides linker can effectively reduce the accumulation of intermediates and improves the content of astaxanthin.Compared with the control strain,the fusion enzyme of ketase and hydroxylase reduced zeaxanthin and canthaxanthin by 7 and 14 times and increased astaxanthin by 1.6 times,respectively.Moreover,9 variant fusion mutants with improved astaxanthin production were generated through directed evolution.Combining these dominant mutants generated a variant,L95S+I206L,which increased the astaxanthin content of 3.8 times than the control strain.The AlphaFold2 assisted structural analysis indicated that these two mutations alter the interaction between the substrate and the enzymes pocket.Our research provided an efficient idea to reduce the accumulation of the intermediate products in complex biosynthesis pathway.展开更多
Designer chromosomes are artificially synthesized chromosomes.Nowadays,these chromosomes have numerous applications ranging from medical research to the development of biofuels.However,some chromosome fragments can in...Designer chromosomes are artificially synthesized chromosomes.Nowadays,these chromosomes have numerous applications ranging from medical research to the development of biofuels.However,some chromosome fragments can interfere with the chemical synthesis of designer chromosomes and eventually limit the widespread use of this technology.To address this issue,this study aimed to develop an interpretable machine learning framework to predict and quantify the synthesis difficulties of designer chromosomes in advance.Through the use of this framework,six key sequence features leading to synthesis difficulties were identified,and an e Xtreme Gradient Boosting model was established to integrate these features.The predictive model achieved high-quality performance with an AUC of 0.895 in cross-validation and an AUC of 0.885 on an independent test set.Based on these results,the synthesis difficulty index(S-index)was proposed as a means of scoring and interpreting synthesis difficulties of chromosomes from prokaryotes to eukaryotes.The findings of this study emphasize the significant variability in synthesis difficulties between chromosomes and demonstrate the potential of the proposed model to predict and mitigate these difficulties through the optimization of the synthesis process and genome rewriting.展开更多
Global society requires new technologies for manufacturing essential chemicals for modern life that are decoupled from fossil fuels.Therefore,Green Chemical Engineering focuses on the areas of green and sustain-able d...Global society requires new technologies for manufacturing essential chemicals for modern life that are decoupled from fossil fuels.Therefore,Green Chemical Engineering focuses on the areas of green and sustain-able development of chemistry and chemical engineering,among which biomanufacturing is an attractive topic.展开更多
Fatty alcohol biosynthesis by oleaginous microbes was a promising alternative to the petroleum or other non-renewable resources-based process. However, low titer and yield hamper the further industrial and commercial ...Fatty alcohol biosynthesis by oleaginous microbes was a promising alternative to the petroleum or other non-renewable resources-based process. However, low titer and yield hamper the further industrial and commercial applications. Here, we developed an efficient strategy to coordinate fatty alcohol with glycolysis which achieved a ‘pull-and-push’ effect to improve fatty alcohol production. Transcript profiling indicated that genes in carbohydrate metabolism were up-regulated significantly in response to high fatty alcohol production. Based on it, 11 glycolysis promoters were screening to express fatty acyl-CoA reductase(FAR) to relate the fatty alcohol production with the up-regulated carbohydrate metabolism, and the fatty alcohol production reached 557 mg/L when FAR was expressed by the promoter of PFBAin. RNA-seq and qRT-PCR analysis demonstrated that a ‘pull-and-push’ effect caused by the coordination system dynamically enhanced the product synthesis flux from top to bottom, which was also testified and intensified by doubled glucose concentration. After manipulating structural and regulatory genes of lipid metabolism, the final strain achieved up to 5.75 g/L fatty alcohol production from modified YPD medium(containing 91 g/L glucose) in shake flasks, which represented the highest titer reported to date. This work offered a feasible and effective reference for dynamic manipulation of fatty acid-derived chemicals synthesis.展开更多
The rapid development of synthetic biology enables the design,construction and optimization of synthetic microbial consortia to achieve specific functions.In China,the“973”project-“Design and Construction of Microb...The rapid development of synthetic biology enables the design,construction and optimization of synthetic microbial consortia to achieve specific functions.In China,the“973”project-“Design and Construction of Microbial Consortia”was funded by the National Basic Research Program of China in January 2014.It was proposed to address the fundamental challenges in engineering natural microbial consortia and reconstructing microbial consortia to meet industrial demands.In this review,we will introduce this“973”project,including the significance of microbial consortia,the fundamental scientific issues,the recent research progresses,and some case studies about synthetic microbial consortia in the past two and a half years.展开更多
The ability to expand genetic code in living cells has emerged as a powerful method with diverse applications.Here,we design re-placement of the anticodons of E.coli tRNAs that recognize codons for 20 natural amino ac...The ability to expand genetic code in living cells has emerged as a powerful method with diverse applications.Here,we design re-placement of the anticodons of E.coli tRNAs that recognize codons for 20 natural amino acids,with three anti-stop codons,resulting in a total of 60 engineered tRNA constructs.We test these constructs one by one in E.coli,and found that six tRNAsCUA(tyrV,serX,hisR,trpT,glnV and leuX),two tRNAsUCA(trpT and leuX)and one tRNAUUA(tyrV)allowed efficient expression of Red Fluorescence Protein(RFP)with the presence of a corresponding stop codon in frame.Furthermore,we exploit the mutual orthogonality of tRNASer CUA,tRNATrpUCA and tRNATyrUUA with corresponding stop codons and demonstrated that the tRNASer CUA and the tRNATrp UCA can provide dynamic range and low crosstalk.Finally,we show the TAG and TGA can not only be used as an"AND gate"circuit to control the translation of target gene,but also be used to control the translation of a prodeoxyviolacein(PDV)pathway and a reporter in parallel.Overall,this work provides flexible tools for translational control and holds great potential to promote synthetic biology studies.展开更多
Yeast artificial chromosomes(YACs) are important tools for sequencing,gene cloning,and transferring large quantities of genetic information.However,the structure and activity of YAC chromatin,as well as the unintended...Yeast artificial chromosomes(YACs) are important tools for sequencing,gene cloning,and transferring large quantities of genetic information.However,the structure and activity of YAC chromatin,as well as the unintended impacts of introducing foreign DNA sequences on DNA-associated biochemical events,have not been widely explored.Here,we showed that abundant genetic elements like TATA box and transcription factor-binding motifs occurred unintentionally in a previously reported datacarrying chromosome(d Chr).In addition,we used state-of-the-art sequencing technologies to comprehensively profile the genetic,epigenetic,transcriptional,and proteomic characteristics of the exogenous d Chr.We found that the data-carrying DNA formed active chromatin with high chromatin accessibility and H3K4 tri-methylation levels.The d Chr also displayed highly pervasive transcriptional ability and transcribed hundreds of noncoding RNAs.The results demonstrated that exogenous artificial chromosomes formed chromatin structures and did not remain as naked or loose plasmids.A better understanding of the YAC chromatin nature will improve our ability to design better data-storage chromosomes.展开更多
Escherichia coli is one of the most important microbial cell factories,but infection by bacteriophages in the environment may have a huge impact on its application in industrial production.Here,we developed a mobile C...Escherichia coli is one of the most important microbial cell factories,but infection by bacteriophages in the environment may have a huge impact on its application in industrial production.Here,we developed a mobile CRISPR-Cas9 based anti-phage system for bacteriophages defense in E.coli.Two conjugative plasmids pGM1(phosphoglucomutase 1)and pGM2 carrying one and two guide RNAs,respectively,were designed to defend against a filamentous phage.The results showed that the pGM1 and pGM2 could decrease the phage infection rate to 1.6%and 0.2%respectively in infected cells.For preventing phage infection in E.coli,the pGM2 decreased the phage infection rate to 0.1%,while pGM1 failed to block phage infection.Sequence verification revealed that point mutations in protospacer or protospacer adjacent motif sequences of the phage genome caused loss of the defense function.These results support the potential application of MCBAS in E.coli cell factories to defend against phage infections.展开更多
Variations in the composition and level of phospholipids （PLs） in yeast cells during industrial ethanol fermentation processes were analyzed. A comparative lipidomic method was used to investigate the changes in tot...Variations in the composition and level of phospholipids （PLs） in yeast cells during industrial ethanol fermentation processes were analyzed. A comparative lipidomic method was used to investigate the changes in total cellular PLs during continuous and fed-batch/batch processes. The phospholipid metabolism in yeast changed during both processes, mainly due to the presence of longchain poly unsaturated fatty acids （PUFA） that contained phosphatidyglycerol （PG）, phosphatidylethanolamine （PE） and phosphatidylserine （PS）. The complexity of the media affected the growth of the yeast and the membrane composition. Yeast incorporated lots of exogenous saturated and PUFAs from the feedstock during the fermentations. During the continuous fermentation, there was an increase in PLs with shorter chains as the fermentation progressed and early in process there were more longchains. During the fed-batch/batch process, the PG species increased as the fermentation progressed. This is probably due to an inositol deficiency in the earlier part of the fermentation.展开更多
基金supported by the National Key Research and Development Program of China(2018YFA0900100)the Natural Science Foundation of Tianjin,China(19JCJQJC63300)Tianjin University。
文摘DNA molecules are green materials with great potential for high-density and long-term data storage.However,the current data-writing process of DNA data storage via DNA synthesis suffers from high costs and the production of hazards,limiting its practical applications.Here,we developed a DNA movable-type storage system that can utilize DNA fragments pre-produced by cell factories for data writing.In this system,these pre-generated DNA fragments,referred to herein as“DNA movable types,”are used as basic writing units in a repetitive way.The process of data writing is achieved by the rapid assembly of these DNA movable types,thereby avoiding the costly and environmentally hazardous process of de novo DNA synthesis.With this system,we successfully encoded 24 bytes of digital information in DNA and read it back accurately by means of high-throughput sequencing and decoding,thereby demonstrating the feasibility of this system.Through its repetitive usage and biological assembly of DNA movable-type fragments,this system exhibits excellent potential for writing cost reduction,opening up a novel route toward an economical and sustainable digital data-storage technology.
基金grateful for the financial supports from the National Key R&D Program of China(2018YFA0902200)the National Natural Science Foundation of China(Program:21878224).
文摘Polymyxin B,produced by Paenibacillus polymyxa,is used as the last line of defense clinically.In this study,exogenous mixture of precursor amino acids increased the level and proportion of polymyxin B1 in the total of polymyxin B analogs of P.polymyxa CJX518-AC(PPAC)from 0.15 g/L and 61.8%to 0.33 g/L and 79.9%,respectively.The co-culture of strain PPAC and recombinant Corynebacterium glutamicum-leu01,which produces high levels of threonine,leucine,and isoleucine,increased polymyxin B1 production to 0.64 g/L.When strains PPAC and C.glu-leu01 simultaneously inoculated into an optimized medium with 20 g/L peptone,polymyxin B1 production was increased to 0.97 g/L.Furthermore,the polymyxin B1 production in the co-culture of strains PPAC and C.glu-leu01 increased to 2.21 g/L after optimized inoculation ratios and fermentation medium with 60 g/L peptone.This study provides a new strategy to improve polymyxin B1 production.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFC2100800)the National Natural Science Foundation of China(Grant No.22208241)+1 种基金China Postdoctoral Science Foundation(Grant No.2023M732591)the Key R&D Program of Shandong Province,China(Grant No.2022SFGC0102).
文摘Genomic rearrangements play a crucial role in shaping biological phenotypic diversity and driving species evolution.Synthetic chromosome rearrangement and modification by LoxP-mediated evolution(SCRaMbLE)has been applied to explore large-scale genomic rearrangements,yet it has been observed that these rearrangements occur exclusively in genomic regions containing loxPsym sites.Here,we found that SCRaMbLE of synthetic yeast harboring synthetic chromosome V and X can generate a variety of synthetic segment insertions into wild-type chromosomes,ranging from 1 to 300 kb.Furthermore,it was revealed that the novel insertions impacted the transcriptional level of neighboring regions and affected the production of exemplar pathway of zeaxanthin.Collectively,our results improve the understanding of the ability of SCRaMbLE to generate complex structural variations in nonsynthetic regions and provide a potential model to explore genomic transposable events.
文摘Genomic rearrangements play a significant role in disease,evolution,and tumorigenesis(Mani and Chinnaiyan,2010).While single nucleotide polymorphisms(SNPs)and small insertions/deletions contribute substantially to genetic variation,discerning the independent impact of structural variations poses a challenge.
基金funded by the Ministry of Science and Technology,the National Key Research and Development Program of China (2021YFC2100800)the National Natural Science Foundation of China (31800719,and 21621004).
文摘catalyzed byβ-carotene hydroxylase(crtZ)andβ-carotene ketolase(crtW)decreases the content of the astaxanthin.Here,we exploited directed evolution of the fusion of crtZ and crtW for improving astaxanthin biosynthesis in Saccharomyces cerevisiae.The results demonstrated that the fusion enzyme of crtZ-crtW with 2 X GGGGS peptides linker can effectively reduce the accumulation of intermediates and improves the content of astaxanthin.Compared with the control strain,the fusion enzyme of ketase and hydroxylase reduced zeaxanthin and canthaxanthin by 7 and 14 times and increased astaxanthin by 1.6 times,respectively.Moreover,9 variant fusion mutants with improved astaxanthin production were generated through directed evolution.Combining these dominant mutants generated a variant,L95S+I206L,which increased the astaxanthin content of 3.8 times than the control strain.The AlphaFold2 assisted structural analysis indicated that these two mutations alter the interaction between the substrate and the enzymes pocket.Our research provided an efficient idea to reduce the accumulation of the intermediate products in complex biosynthesis pathway.
基金supported by the National Natural Science Foundation of China(21621004,31861143017,21907074)the National Key Research and Development Program of China(2019YFA0906600)。
文摘Designer chromosomes are artificially synthesized chromosomes.Nowadays,these chromosomes have numerous applications ranging from medical research to the development of biofuels.However,some chromosome fragments can interfere with the chemical synthesis of designer chromosomes and eventually limit the widespread use of this technology.To address this issue,this study aimed to develop an interpretable machine learning framework to predict and quantify the synthesis difficulties of designer chromosomes in advance.Through the use of this framework,six key sequence features leading to synthesis difficulties were identified,and an e Xtreme Gradient Boosting model was established to integrate these features.The predictive model achieved high-quality performance with an AUC of 0.895 in cross-validation and an AUC of 0.885 on an independent test set.Based on these results,the synthesis difficulty index(S-index)was proposed as a means of scoring and interpreting synthesis difficulties of chromosomes from prokaryotes to eukaryotes.The findings of this study emphasize the significant variability in synthesis difficulties between chromosomes and demonstrate the potential of the proposed model to predict and mitigate these difficulties through the optimization of the synthesis process and genome rewriting.
文摘Global society requires new technologies for manufacturing essential chemicals for modern life that are decoupled from fossil fuels.Therefore,Green Chemical Engineering focuses on the areas of green and sustain-able development of chemistry and chemical engineering,among which biomanufacturing is an attractive topic.
基金supported by the National Natural Science Foundation of China (21621004)Young Elite Scientists Sponsorship Program by Tianjin (TJSQNTJ-2018-16)
文摘Fatty alcohol biosynthesis by oleaginous microbes was a promising alternative to the petroleum or other non-renewable resources-based process. However, low titer and yield hamper the further industrial and commercial applications. Here, we developed an efficient strategy to coordinate fatty alcohol with glycolysis which achieved a ‘pull-and-push’ effect to improve fatty alcohol production. Transcript profiling indicated that genes in carbohydrate metabolism were up-regulated significantly in response to high fatty alcohol production. Based on it, 11 glycolysis promoters were screening to express fatty acyl-CoA reductase(FAR) to relate the fatty alcohol production with the up-regulated carbohydrate metabolism, and the fatty alcohol production reached 557 mg/L when FAR was expressed by the promoter of PFBAin. RNA-seq and qRT-PCR analysis demonstrated that a ‘pull-and-push’ effect caused by the coordination system dynamically enhanced the product synthesis flux from top to bottom, which was also testified and intensified by doubled glucose concentration. After manipulating structural and regulatory genes of lipid metabolism, the final strain achieved up to 5.75 g/L fatty alcohol production from modified YPD medium(containing 91 g/L glucose) in shake flasks, which represented the highest titer reported to date. This work offered a feasible and effective reference for dynamic manipulation of fatty acid-derived chemicals synthesis.
基金the Ministry of Science and Technology of China(“973”Program:2014CB745100).
文摘The rapid development of synthetic biology enables the design,construction and optimization of synthetic microbial consortia to achieve specific functions.In China,the“973”project-“Design and Construction of Microbial Consortia”was funded by the National Basic Research Program of China in January 2014.It was proposed to address the fundamental challenges in engineering natural microbial consortia and reconstructing microbial consortia to meet industrial demands.In this review,we will introduce this“973”project,including the significance of microbial consortia,the fundamental scientific issues,the recent research progresses,and some case studies about synthetic microbial consortia in the past two and a half years.
基金The authors are grateful for the financial support fromthe National Key Research and Development Program of China(No.2018YFA0903700)the National Natural Science Foundation of China(Nos.31800719,21621004)the International(regional)cooperation and exchange projects(No.31861143017)。
文摘The ability to expand genetic code in living cells has emerged as a powerful method with diverse applications.Here,we design re-placement of the anticodons of E.coli tRNAs that recognize codons for 20 natural amino acids,with three anti-stop codons,resulting in a total of 60 engineered tRNA constructs.We test these constructs one by one in E.coli,and found that six tRNAsCUA(tyrV,serX,hisR,trpT,glnV and leuX),two tRNAsUCA(trpT and leuX)and one tRNAUUA(tyrV)allowed efficient expression of Red Fluorescence Protein(RFP)with the presence of a corresponding stop codon in frame.Furthermore,we exploit the mutual orthogonality of tRNASer CUA,tRNATrpUCA and tRNATyrUUA with corresponding stop codons and demonstrated that the tRNASer CUA and the tRNATrp UCA can provide dynamic range and low crosstalk.Finally,we show the TAG and TGA can not only be used as an"AND gate"circuit to control the translation of target gene,but also be used to control the translation of a prodeoxyviolacein(PDV)pathway and a reporter in parallel.Overall,this work provides flexible tools for translational control and holds great potential to promote synthetic biology studies.
基金supported by the National Key Research and Development Program of China (2121YFA0909300)the National Natural Science Foundation of China (31861143017,21621004+1 种基金31901019)the China Postdoctoral Science Foundation(2021M692389)。
文摘Yeast artificial chromosomes(YACs) are important tools for sequencing,gene cloning,and transferring large quantities of genetic information.However,the structure and activity of YAC chromatin,as well as the unintended impacts of introducing foreign DNA sequences on DNA-associated biochemical events,have not been widely explored.Here,we showed that abundant genetic elements like TATA box and transcription factor-binding motifs occurred unintentionally in a previously reported datacarrying chromosome(d Chr).In addition,we used state-of-the-art sequencing technologies to comprehensively profile the genetic,epigenetic,transcriptional,and proteomic characteristics of the exogenous d Chr.We found that the data-carrying DNA formed active chromatin with high chromatin accessibility and H3K4 tri-methylation levels.The d Chr also displayed highly pervasive transcriptional ability and transcribed hundreds of noncoding RNAs.The results demonstrated that exogenous artificial chromosomes formed chromatin structures and did not remain as naked or loose plasmids.A better understanding of the YAC chromatin nature will improve our ability to design better data-storage chromosomes.
基金support from the National Key Research and Development Program of China(Grant No.2019YFA0903800)the National Natural Science Foundation of China(Grant Nos.31800719,21621004)the International(regional)cooperation and exchange projects(Grant No.31861143017).
文摘Escherichia coli is one of the most important microbial cell factories,but infection by bacteriophages in the environment may have a huge impact on its application in industrial production.Here,we developed a mobile CRISPR-Cas9 based anti-phage system for bacteriophages defense in E.coli.Two conjugative plasmids pGM1(phosphoglucomutase 1)and pGM2 carrying one and two guide RNAs,respectively,were designed to defend against a filamentous phage.The results showed that the pGM1 and pGM2 could decrease the phage infection rate to 1.6%and 0.2%respectively in infected cells.For preventing phage infection in E.coli,the pGM2 decreased the phage infection rate to 0.1%,while pGM1 failed to block phage infection.Sequence verification revealed that point mutations in protospacer or protospacer adjacent motif sequences of the phage genome caused loss of the defense function.These results support the potential application of MCBAS in E.coli cell factories to defend against phage infections.
文摘Variations in the composition and level of phospholipids （PLs） in yeast cells during industrial ethanol fermentation processes were analyzed. A comparative lipidomic method was used to investigate the changes in total cellular PLs during continuous and fed-batch/batch processes. The phospholipid metabolism in yeast changed during both processes, mainly due to the presence of longchain poly unsaturated fatty acids （PUFA） that contained phosphatidyglycerol （PG）, phosphatidylethanolamine （PE） and phosphatidylserine （PS）. The complexity of the media affected the growth of the yeast and the membrane composition. Yeast incorporated lots of exogenous saturated and PUFAs from the feedstock during the fermentations. During the continuous fermentation, there was an increase in PLs with shorter chains as the fermentation progressed and early in process there were more longchains. During the fed-batch/batch process, the PG species increased as the fermentation progressed. This is probably due to an inositol deficiency in the earlier part of the fermentation.
