Metabolic engineering最新文献

{"title":"The faucet knob effect of DptE crotonylation on the initial flow of daptomycin biosynthesis","authors":"Wen-Li Gao ,&nbsp;Lie Ma ,&nbsp;Meng-Han Li ,&nbsp;Wei-Feng Xu ,&nbsp;Chen-Fan Sun ,&nbsp;Qing-Wei Zhao ,&nbsp;Xin-Ai Chen ,&nbsp;Zhong-Yuan Lyu ,&nbsp;Yong-quan Li","doi":"10.1016/j.ymben.2024.11.003","DOIUrl":"10.1016/j.ymben.2024.11.003","url":null,"abstract":"<div><div>We propose here that acylation modification of actinomycete proteins is a restrictive system that limits the excessive synthesis of secondary metabolites, its mechanism has not been clearly elucidated before. We used crotonylation as an example to investigate the acylation effect in the daptomycin biosynthesis by <em>Streptomyces roseosporus</em>. Our experiments revealed abundant crotonylation of numerous secondary metabolic enzymes in <em>Streptomyces roseosporus,</em> a daptomycin producer. DptE, which initiates daptomycin biosynthesis, is crotonylated at K454. We experimentally identified the corresponding DptE crotonyltransferase Kct1 and decrotonylase CobB. Further studies consistently confirmed that decrotonylation increases DptE activity. Decrotonylation functions like loosening a faucet knob, increasing substrate channel throughput and the initial flow of daptomycin biosynthesis. Moreover, DptE catalytic activity was enhanced via K454 and neighboring residues K184 and Q420 mutation, increasing daptomycin yield by 132%; daptomycin biosynthesis related metabolism activities also increased. Substrate channel prediction revealed 38% higher throughput for mutant DptE (K454I/K184Q/Q420N) than crotonylated DptE. Molecular dynamics (MD) simulations revealed significant increases in flexibility and substrate affinity of the mutant. In summary, we elucidated the faucet knob effect of DptE crotonylation on the initial flow of daptomycin biosynthesis and adopted decrotonylation to generate high-yield industrial strains.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":"87 ","pages":"Pages 1-10"},"PeriodicalIF":6.8,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142621734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Versatile xylose and arabinose genetic switches development for yeasts","authors":"Shuhui Guo ,&nbsp;Juhua Du ,&nbsp;Donghan Li ,&nbsp;Jinghui Xiong ,&nbsp;Ye Chen","doi":"10.1016/j.ymben.2024.11.004","DOIUrl":"10.1016/j.ymben.2024.11.004","url":null,"abstract":"<div><div>Inducible transcription systems are essential tools in genetic engineering, where tight control, strong inducibility and fast response with cost-effective inducers are highly desired. However, existing systems in yeasts are rarely used in large-scale fermentations due to either cost-prohibitive inducers or incompatible performance. Here, we developed powerful xylose and arabinose induction systems in <em>Saccharomyces cerevisiae</em>, utilizing eukaryotic activators XlnR and AraR^A from <em>Aspergillus</em> species and bacterial repressors XylR and AraR^R. By integrating these signals into a highly-structured synthetic promoter, we created dual-mode systems with strong outputs and minimal leakiness. These systems demonstrated over 4000- and 300-fold regulation with strong activation and rapid response. The dual-mode xylose system was fully activated by xylose-rich agricultural residues like corncob hydrolysate, outperforming existing systems in terms of leakiness, inducibility, dynamic range, induction rate, and growth impact on host. We validated their utility in metabolic engineering with high-titer linalool production and demonstrated the transferability of the XlnR-based xylose induction system to <em>Pichia pastoris</em>, <em>Candida glabrata</em> and <em>Candida albicans</em>. This work provides robust genetic switches for yeasts and a general strategy for integrating activation-repression signals into synthetic promoters to achieve optimal performance.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":"87 ","pages":"Pages 21-36"},"PeriodicalIF":6.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142621735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterologous biosynthesis of betanin triggers metabolic reprogramming in tobacco","authors":"Xun Jiang ,&nbsp;Zhuoxiang Zhang ,&nbsp;Xiuming Wu ,&nbsp;Changmei Li,&nbsp;Xuan Sun,&nbsp;Fengyan Wu,&nbsp;Aiguo Yang,&nbsp;Changqing Yang","doi":"10.1016/j.ymben.2024.11.002","DOIUrl":"10.1016/j.ymben.2024.11.002","url":null,"abstract":"<div><div>Engineering of a specialized metabolic pathway in plants is a promising approach to produce high-value bioactive compounds to address the challenges of climate change and population growth. Understanding the interaction between the heterologous pathway and the native metabolic network of the host plant is crucial for optimizing the engineered system and maximizing the yield of the target compound. In this study, we performed transcriptomic, metabolomic and metagenomic analysis of tobacco (<em>Nicotiana tabacum</em>) plants engineered to produce betanin, an alkaloid pigment that is found in <em>Caryophyllaceae</em> plants. Our data reveals that, in a dose-dependent manor, the biosynthesis of betanin promotes carbohydrate metabolism and represses nitrogen metabolism in the leaf, but enhances nitrogen assimilation and metabolism in the root. By supplying nitrate or ammonium, the accumulation of betanin increased by 1.5–3.8-fold in leaves and roots of the transgenic plants, confirming the pivotal role of nitrogen in betanin production. In addition, the rhizosphere microbial community is reshaped to reduce denitrification and increase respiration and oxidation, assistant to suppress nitrogen loss. Our analysis not only provides a framework for evaluating the pleiotropic effects of an engineered metabolic pathway on the host plant, but also facilitates the development of novel strategies to balance the heterologous process and the native metabolic network for the high-yield and nutrient-efficient production of bioactive compounds in plants.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":"86 ","pages":"Pages 308-325"},"PeriodicalIF":6.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142591159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applying metabolic control strategies to engineered T cell cancer therapies","authors":"Andrea C. Fox,&nbsp;John Blazeck","doi":"10.1016/j.ymben.2024.10.009","DOIUrl":"10.1016/j.ymben.2024.10.009","url":null,"abstract":"<div><div>Chimeric antigen receptor (CAR) T cells are an engineered immunotherapy that express synthetic receptors to recognize and kill cancer cells. Despite their success in treating hematologic cancers, CAR T cells have limited efficacy against solid tumors, in part due to the altered immunometabolic profile within the tumor environment, which hinders T cell proliferation, infiltration, and anti-tumor activity. For instance, CAR T cells must compete for essential nutrients within tumors, while resisting the impacts of immunosuppressive metabolic byproducts. In this review, we will describe the altered metabolic features within solid tumors that contribute to immunosuppression of CAR T cells. We'll discuss how overexpression of key metabolic enzymes can enhance the ability of CAR T cells to resist corresponding tumoral metabolic changes or even revert the metabolic profile of a tumor to a less inhibitory state. In addition, metabolic remodeling is intrinsically linked to T cell activity, differentiation, and function, such that metabolic engineering strategies can also promote establishment of more or less efficacious CAR T cell phenotypes. Overall, we will show how applying metabolic engineering strategies holds significant promise in improving CAR T cells for the treatment of solid tumors.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":"86 ","pages":"Pages 250-261"},"PeriodicalIF":6.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multiscale hybrid modelling methodology for cell cultures enabled by enzyme-constrained dynamic metabolic flux analysis under uncertainty","authors":"Oliver Pennington ,&nbsp;Sebastián Espinel Ríos ,&nbsp;Mauro Torres Sebastian ,&nbsp;Alan Dickson ,&nbsp;Dongda Zhang","doi":"10.1016/j.ymben.2024.10.013","DOIUrl":"10.1016/j.ymben.2024.10.013","url":null,"abstract":"<div><div>Mammalian cell cultures make a significant contribution to the pharmaceutical industry. They produce many of the biopharmaceuticals obtaining FDA-approval each year. Motivated by quality-by-design principles, various modelling methodologies are frequently trialled to gain insight into these bioprocesses. However, these systems are highly complex and uncertain, involving dynamics at different scales, both in time and space, making them challenging to model in a comprehensive and fully mechanistic manner. This study develops a machine-learning-supported multiscale modelling framework of cell cultures, linking the macroscale bioprocess dynamics to the microscale metabolic flux distribution. As a relevant biopharmaceutical case study, we consider the production of Trastuzumab by Chinese Hamster Ovary (CHO) cells in batch. A macroscale hybrid model is constructed by integrating macro-kinetic and machine-learning approaches. Enzyme-constrained Dynamic Metabolic Flux Analysis (ecDMFA) is adopted to calculate flux distributions based on the dynamic predictions of the hybrid model. Uncertainty estimation of the multiscale model is conducted through bootstrapping. Judging from experimental data, our hybrid model can reduce the modelling error of the macroscale dynamics to 8.0%; a 70% reduction from the purely mechanistic model. In addition, the predicted dynamic flux distribution aligns with observations seen in literature, highlighting important metabolic changes throughout the process. Model uncertainty is maintained at a low level, demonstrating the trustworthiness of the predictions. Overall, our comprehensive modelling framework has the potential to facilitate the development of digital twins in the biopharmaceutical industry.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":"86 ","pages":"Pages 274-287"},"PeriodicalIF":6.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142558206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering peroxisomal surface display for enhanced biosynthesis in the emerging yeast Kluyveromyces marxianus","authors":"Shane Bassett,&nbsp;Jonathan C. Suganda,&nbsp;Nancy A. Da Silva","doi":"10.1016/j.ymben.2024.10.014","DOIUrl":"10.1016/j.ymben.2024.10.014","url":null,"abstract":"<div><div>The non-conventional yeast <em>Kluyveromyces marxianus</em> is a promising microbial host for industrial biomanufacturing. With the recent development of Cas9-based genome editing systems and other novel synthetic biology tools for <em>K. marxianus</em>, engineering of this yeast has become far more accessible. Enzyme colocalization is a proven approach to increase pathway flux and the synthesis of non-native products. Here, we engineer <em>K. marxianus</em> to enable peroxisomal surface display, an enzyme colocalization technique for displaying enzymes on the peroxisome membrane via an anchoring motif from the peroxin Pex15. The native <em>Km</em>Pex15 anchoring motif was identified and fused to GFP, resulting in successful localization to the surface of the peroxisomes. To demonstrate the advantages for pathway localization, the <em>Pseudomonas savastanoi</em> IaaM and IaaH enzymes were co-displayed on the peroxisome surface; this increased production of indole-3-acetic acid 7.9-fold via substrate channeling effects. We then redirected pathway flux by displaying the violacein pathway enzymes VioE and VioD from <em>Chromobacterium violaceum</em>, increasing selectivity of proviolacein to prodeoxyviolacein by 2.5-fold. Finally, we improved direct access to peroxisomal acetyl-CoA and increased titers of the polyketide triacetic acid lactone (TAL) by 2-fold through concurrent display of the proteins Cat2, Acc1, and the type III PKS 2-pyrone synthase from <em>Gerbera hybrida</em> relative to the same three enzymes diffusing in the cytosol. We further improved TAL production by up to 2.1-fold through engineering peroxisome morphology and lifespan. Our findings demonstrate that peroxisomal surface display is an efficient enzyme colocalization strategy in <em>K. marxianus</em> and applicable for improving production of a wide range of non-native products.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":"86 ","pages":"Pages 326-336"},"PeriodicalIF":6.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142569124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generation of a Vibrio-based platform for efficient conversion of raffinose through Adaptive Laboratory Evolution on a solid medium","authors":"Sunghwa Woo ,&nbsp;Yong Hee Han ,&nbsp;Hye Kyung Lee ,&nbsp;Dongyeop Baek ,&nbsp;Myung Hyun Noh ,&nbsp;Sukjae Han ,&nbsp;Hyun Gyu Lim ,&nbsp;Gyoo Yeol Jung ,&nbsp;Sang Woo Seo","doi":"10.1016/j.ymben.2024.11.001","DOIUrl":"10.1016/j.ymben.2024.11.001","url":null,"abstract":"<div><div>Raffinose, a trisaccharide abundantly found in soybeans, is a potential alternative carbon source for biorefineries. Nevertheless, residual intermediate di- or monosaccharides and low catabolic efficiency limit raffinose use through conventional microbial hosts. This study presents a <em>Vibrio</em>-based platform to convert raffinose efficiently. <em>Vibrio</em> sp. dhg was selected as the starting strain for the Adaptive Laboratory Evolution (ALE) strategy to leverage its significantly higher metabolic efficiency. We conducted ALE on a solid minimal medium supplemented with raffinose to prevent the enrichment of undesired phenotypes due to the shared effect of extracellular raffinose hydrolysis among multiple strains. As a result, we generated the VRA10 strain that efficiently utilizes raffinose without leaving behind degraded di- or monosaccharides, achieving a notable growth rate (0.40 h⁻¹) and raffinose consumption rate (1.2 g/g_dcw/h). Whole genome sequencing and reverse engineering identified that a missense mutation in the <em>melB</em> gene (encoding a melibiose/raffinose:sodium symporter) and the deletion of the two <em>galR</em> genes (encoding transcriptional repressors for galactose catabolism) facilitated rapid raffinose utilization. The further engineered strain produced 6.2 g/L of citramalate from 20 g/L of raffinose. This study will pave the way for the efficient utilization of diverse raffinose-rich byproducts and the expansion of alternative carbon streams in biorefinery applications.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":"86 ","pages":"Pages 300-307"},"PeriodicalIF":6.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142569125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering Halomonas bluephagenesis for synthesis of polyhydroxybutyrate (PHB) in the presence of high nitrogen containing media","authors":"Zhongnan Zhang ,&nbsp;Mingwei Shao ,&nbsp;Ge Zhang ,&nbsp;Simian Sun ,&nbsp;Xueqing Yi ,&nbsp;Zonghao Zhang ,&nbsp;Hongtao He ,&nbsp;Kang Wang ,&nbsp;Qitiao Hu ,&nbsp;Qiong Wu ,&nbsp;Guo-Qiang Chen","doi":"10.1016/j.ymben.2024.10.012","DOIUrl":"10.1016/j.ymben.2024.10.012","url":null,"abstract":"<div><div>The trade-offs exist between microbial growth and bioproduct synthesis including intracellular polyester polyhydroxybutyrate (PHB). Under nitrogen limitation, more carbon flux is directed to PHB synthesis while growth is inhibited with diminishing overall carbon utilization, similar to the suboptimal carbon utilization during glycolysis-derived pyruvate decarboxylation. This study reconfigured the central carbon network of <em>Halomonas blu</em><em>e</em><em>phagenesis</em> to improve PHB yield theoretically and practically. It was found that the downregulation of glutamine synthetase (GS) activity led to a synchronous improvement on PHB accumulation and cell growth under nitrogen non-limitation condition, increasing the PHB yield from glucose (g/g) to 85% of theoretical yield, PHB titer from 7.6 g/L to 12.9 g/L, and from 51 g/L to 65 g/L when grown in shake flasks containing a rich N-source, and grown in a fed-batch cultivation conducted in a 7-L bioreactor also containing a rich N-source, respectively. Results offer better metabolic balance between glucose conversion efficiency and microbial growth for economic PHB production.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":"86 ","pages":"Pages 242-249"},"PeriodicalIF":6.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Not all cytochrome b5s are created equal: How a specific CytB5 boosts forskolin biosynthesis in Saccharomyces cerevisiae","authors":"Victor Forman ,&nbsp;Dan Luo ,&nbsp;Sotirios C. Kampranis ,&nbsp;Dan Stærk ,&nbsp;Birger Lindberg Møller ,&nbsp;Irini Pateraki","doi":"10.1016/j.ymben.2024.10.008","DOIUrl":"10.1016/j.ymben.2024.10.008","url":null,"abstract":"<div><div>Cytochrome B5s, or CytB5s, are small heme-binding proteins, ubiquitous across all kingdoms of life that serve mainly as electron donors to enzymes engaged in oxidative reactions. They often function as redox partners of the cytochrome P450s (CYPs), a superfamily of enzymes participating in multiple biochemical processes. In plants, CYPs catalyze key reactions in the biosynthesis of plant specialized metabolites with their activity dependent on electron donation often from cytochrome P450 oxidoreductases (CPRs or PORs). In eukaryotic microsomal CYPs, CytB5s frequently participate in the electron transfer process although their exact role remains understudied, especially in plant systems. In this study, we assess the role of CytB5s in the heterologous biotechnological production of plant specialized metabolites in yeast. For this, we used as a case-study the biosynthesis of forskolin - a bioactive diterpenoid produced exclusively from the plant <em>Coleus forskohlii</em>. The complete biosynthetic pathway for forskolin is known and includes three CYP enzymes. We reconstructed the entire forskolin pathway in the yeast <em>Saccharomyces cerevisiae,</em> and upon co-expression of the three CytB5s - identified in <em>C. forskohlii</em> transcriptomes - alleviation of a CYP-related bottleneck step was noticed only when a specific CytB5, <em>Cf</em>CytB5A, was used. Co-expression of <em>Cf</em>CytB5A in yeast, in combination with forskolin pathway engineering, resulted in forskolin production at titers of 1.81 g/L in a bioreactor. Our findings demonstrate that CytB5s not only play an important role in plant specialized metabolism but also, they can interact with precision with specific CYPs, indicating that the properties of CytB5s are far from understood. Moreover, our work highlights how CytB5s may act as indispensable components in the sustainable microbial production of plant metabolites, when their biosynthetic pathways involve CYP enzymes.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":"86 ","pages":"Pages 288-299"},"PeriodicalIF":6.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142503498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptive laboratory evolution and metabolic engineering of Cupriavidus necator for improved catabolism of volatile fatty acids","authors":"Eric C. Holmes,&nbsp;Alissa C. Bleem,&nbsp;Christopher W. Johnson,&nbsp;Gregg T. Beckham","doi":"10.1016/j.ymben.2024.10.011","DOIUrl":"10.1016/j.ymben.2024.10.011","url":null,"abstract":"<div><div>Bioconversion of high-volume waste streams into value-added products will be an integral component of the growing bioeconomy. Volatile fatty acids (VFAs) (e.g., butyrate, valerate, and hexanoate) are an emerging and promising waste-derived feedstock for microbial carbon upcycling. <em>Cupriavidus necator</em> H16 is a favorable host for conversion of VFAs into various bioproducts due to its diverse carbon metabolism, ease of metabolic engineering, and use at industrial scales. Here, we report that a common strategy to improve product titers in <em>C. necator</em>, deletion of the polyhydroxybutyrate (PHB) biosynthetic operon, results in a significant growth defect on VFA substrates. Using adaptive laboratory evolution, we identify mutations to the regulator gene <em>phaR</em>, the two-component response regulator-histidine kinase pair encoded by <em>H16_A1372</em>/<em>H16_A1373</em>, and the tripartite transporter assembly encoded by <em>H16_A2296</em>-<em>A2298</em> as causative for improved growth on VFA substrates. Deletion of <em>phaR</em> and <em>H16_A1373</em> led to significantly reduced NADH abundance accompanied by large changes to expression of genes involved in carbon metabolism, balance of electron carriers, and oxidative stress tolerance that may be responsible for improved growth of these engineered strains. These results provide insight into the role of PHB biosynthesis in carbon and energy metabolism and highlight a key role for the regulator PhaR in global regulatory networks. By combining mutations, we generated platform strains with significant growth improvements on VFAs, which can enable improved conversion of waste-derived VFA substrates to target bioproducts.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":"86 ","pages":"Pages 262-273"},"PeriodicalIF":6.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}