Iterative genome engineering of E. coli for fed-batch production of L-tyrosine.
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1102680 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:In this project we aim to construct a tyrosine-producing E. coli strain through iterative steps of genome engineering. High PEP availability through knockout of the PTS was combined with the precise, in-place genomic integration of several engineering interventions, known to increase L-tyrosine production yields, to create a tyrosine-overproducing E. coli strain that can function as a platform for further engineering and optimization. Utilizing a design-build-test-learn (DBTL) cycle, an evolved pts-knockout E. coli strain was equipped with optimizations of the aroG, aroB and tyrA genes and cultivated under batch and fed-batch conditions. Subsequently, metabolomics, transcriptomics and proteomics samples from the fed-batch experiments were analyzed to inform the design of new genomic interventions.
2025-07-01 | GSE264483 | GEO
Project description:Time-course transcriptomic profilling of the oleaginous yeast Yarrowia lipolytica, during a controlled fed-batch. A nitrogen limitation was applied during the course of the fed-batch to initiate de novo biolipid synthesis.
2011-05-15 | GSE29046 | GEO
Project description:Time-course transcriptomic profilling of the oleaginous yeast Yarrowia lipolytica, during a controlled fed-batch. A nitrogen limitation was applied during the course of the fed-batch to initiate de novo biolipid synthesis. Dual staining, one replicate per slide. On each slide, a time point sample and a reference sample are spotted. Reference samples were obtained by pooling the RNAs from the time-course samples.
2011-05-15 | E-GEOD-29046 | biostudies-arrayexpress
Project description:Fed-batch cultivation of recombinant Chinese hamster ovary (CHO) cell lines is one of the most widely used production mode for commercial manufacturing of recombinant protein therapeutics. Furthermore, fed-batch cultivations are often conducted as biphasic processes where culture temperature is decreased to maximize volumetric product yields. However, it still remains to be elucidated which intracellular regulatory elements actually control the observed pro-productive phenotypes. Recently, several studies have revealed microRNAs (miRNAs) to be important molecular switches of cell phenotypes since single miRNAs are capable of regulating entire physiological pathways. In this study, we analyzed miRNA profiles of two different recombinant CHO cell lines (high and low producer), and compared them to a non-producing CHO DG44 host cell line during fed-batch cultivation at 37 versus 30 °C culture temperature. Taking advantage of next-generation sequencing combined with cluster, correlation and differential expression analyses, we could identify 89 different miRNAs, which might be interesting for CHO cell engineering. Functional validation experiments using 19 validated target miRNAs confirmed that these miRNAs indeed induced changes in process relevant phenotypes such as recombinant protein production, apoptosis, necrosis and proliferation. Furthermore, computational miRNA target prediction combined with functional clustering identified putative target genes and cellular pathways, which might be regulated by these miRNAs. Taken together, our study systematically identified novel target miRNAs during different phases and conditions of a biphasic fed-batch process and functionally evaluated their potential for host cell engineering.
2016-04-03 | GSE72945 | GEO
Project description:Fed-batch cultivation of recombinant Chinese hamster ovary (CHO) cell lines is one of the most widely used production mode for commercial manufacturing of recombinant protein therapeutics. Furthermore, fed-batch cultivations are often conducted as biphasic processes where culture temperature is decreased to maximize volumetric product yields. However, it still remains to be elucidated which intracellular regulatory elements actually control the observed pro-productive phenotypes. Recently, several studies have revealed microRNAs (miRNAs) to be important molecular switches of cell phenotypes since single miRNAs are capable of regulating entire physiological pathways. In this study, we analyzed miRNA profiles of two different recombinant CHO cell lines (high and low producer), and compared them to a non-producing CHO DG44 host cell line during fed-batch cultivation at 37 versus 30 °C culture temperature. Taking advantage of next-generation sequencing combined with cluster, correlation and differential expression analyses, we could identify 89 different miRNAs, which might be interesting for CHO cell engineering. Functional validation experiments using 19 validated target miRNAs confirmed that these miRNAs indeed induced changes in process relevant phenotypes such as recombinant protein production, apoptosis, necrosis and proliferation. Furthermore, computational miRNA target prediction combined with functional clustering identified putative target genes and cellular pathways, which might be regulated by these miRNAs. Taken together, our study systematically identified novel target miRNAs during different phases and conditions of a biphasic fed-batch process and functionally evaluated their potential for host cell engineering. 36 miRNA libraries from three different CHO cell lines and two process condition. In the control run temperature was maintained at 30°C, while temperature was reduced to 30°C after reaching mid exponential phase
2016-04-03 | E-GEOD-72945 | biostudies-arrayexpress
Project description:iSMNN: batch effect correction for single-cell RNA-seq data via iterative supervised mutual nearest neighbor refinement
| PRJNA675647 | ENA
Project description:BackgroundAcarbose, as an alpha-glucosidase inhibitor, is widely used clinically to treat type II diabetes. In its industrial production, Actinoplanes sp. SE50/110 is used as the production strain. Lack of research on its regulatory mechanisms and unexplored gene targets are major obstacles to rational strain design. Here, transcriptome sequencing was applied to uncover more gene targets and rational genetic engineering was performed to increase acarbose production.ResultsIn this study, with the help of transcriptome information, a TetR family regulator (TetR1) was identified and confirmed to have a positive effect on the synthesis of acarbose by promoting the expression of acbB and acbD. Some genes with low expression levels in the acarbose biosynthesis gene cluster were overexpressed and this resulted in a significant increase in acarbose yield. In addition, the regulation of metabolic pathways was performed to retain more glucose-1-phosphate for acarbose synthesis by weakening the glycogen synthesis pathway and strengthening the glycogen degradation pathway. Eventually, with a combination of multiple strategies and fed-batch fermentation, the yield of acarbose in the engineered strain increased 58% compared to the parent strain, reaching 8.04 g/L, which is the highest fermentation titer reported.ConclusionsIn our research, acarbose production had been effectively and steadily improved through genetic engineering based on transcriptome analysis and fed-batch culture strategy.
| S-EPMC9685945 | biostudies-literature
Project description:BackgroundA fundamental problem associated with E. coli fermentations is the difficulty in achieving high cell densities in batch cultures, attributed in large part to the production and accumulation of acetate through a phenomenon known as overflow metabolism when supplying enough glucose for the cell density desired. Although a fed-batch configuration is the standard method for reducing such issues, traditional fed-batch systems require components which become problematic when applying them at smaller scale. One alternative has been the development of a system whereby the enzymatic degradation of starch is used to release glucose at a controlled rate. However, to date, amylolytic enzymes have only been applied to the culture exogenously, whereas our goal is to design and construct a self-secreting amylolytic chassis capable of self-regulated enzyme-based fed-batch fermentation.ResultsA putative glucoamylase from C. violaceum has been cloned and expressed in E. coli BL21(DE3) and W3110, which exhibits significant glucose releasing amylolytic activity. Extracellular amylolytic activity was enhanced following a replacement of the enzymes native signal peptide with the DsbA signal sequence, contributing to a glucoamylase secreting strain capable of utilising starch as a sole carbon source in defined media. Introduction of PcstA, a glucose sensitive K12 compatible promoter, and the incorporation of this alongside C. violaceum glucoamylase in E. coli W3110, gave rise to increased cell densities in cultures grown on starch (OD600 ∼ 30) compared to those grown on an equivalent amount of glucose (OD600 ∼ 15). Lastly, a novel self-secreting enzyme-based fed-batch fermentation system was demonstrated via the simultaneous expression of the C. violaceum glucoamylase and a recombinant protein of interest (eGFP), resulting in a fourfold increase in yield when grown in media containing starch compared with the glucose equivalent.ConclusionsThis study has developed, through the secretion of a previously uncharacterised bacterial glucoamylase, a novel amylolytic E. coli strain capable of direct starch to glucose conversion. The ability of this strain to achieve increased cell densities as well as an associated increase in recombinant protein yield when grown on starch compared with an equivalent amount of glucose, demonstrates for the first time a cell engineering approach to enzyme-based fed-batch fermentation.
| S-EPMC8310608 | biostudies-literature
Project description:In the current study, we present iSMNN, a supervised batch effect correction method for scRNA-seq data via multiple iterations of mutual nearest neighbor refinement. To validate the performance of iSMNN, we performed single-cell RNA-seq for adult murine heart using 10X Chromium platform.
2021-04-14 | GSE161138 | GEO
Project description:BackgroundGeraniol is an acyclic monoterpene alcohol, which exhibits good prospect as a gasoline alternative. Geraniol is naturally encountered in plants at low concentrations and an attractive target for microbial engineering. Geraniol has been heterologously produced in Escherichia coli, but the low titer hinders its industrial applications. Moreover, bioconversion of geraniol by E. coli remains largely unknown.ResultsRecombinant overexpression of Ocimum basilicum geraniol synthase, Abies grandis geranyl diphosphate synthase, and a heterotic mevalonate pathway in E. coli BL21 (DE3) enabled the production of up to 68.6 ± 3 mg/L geraniol in shake flasks. Initial fed-batch fermentation only increased geraniol production to 78.8 mg/L. To further improve the production yield, the fermentation conditions were optimized. Firstly, 81.4 % of volatile geraniol was lost during the first 5 h of fermentation in a solvent-free system. Hence, isopropyl myristate was added to the culture medium to form an aqueous-organic two-phase culture system, which effectively prevented volatilization of geraniol. Secondly, most of geraniol was eventually biotransformed into geranyl acetate by E. coli, thus decreasing geraniol production. For the first time, we revealed the role of acetylesterase (Aes, EC 3.1.1.6) from E. coli in hydrolyzing geranyl acetate to geraniol, and production of geraniol was successfully increased to 2.0 g/L under controlled fermentation conditions.ConclusionsAn efficient geraniol production platform was established by overexpressing several key pathway proteins in engineered E. coli strain combined with a controlled fermentation system. About 2.0 g/L geraniol was obtained using our controllable aqueous-organic two-phase fermentation system, which is the highest yield to date. In addition, the interconversion between geraniol and geranyl acetate by E. coli was first elucidated. This study provided a new and promising strategy for geraniol biosynthesis, which laid a basis for large-scale industrial application.
| S-EPMC4787002 | biostudies-literature