Synthetic and Systems Biotechnology最新文献

{"title":"Hfq modulates system-wide regulatory networks controlling biocontrol property in Lysobacter enzymogenes","authors":"Xinyi Cheng ,&nbsp;Wenhui Chen ,&nbsp;Yangyang Zhao ,&nbsp;Yancun Zhao ,&nbsp;Fengquan Liu ,&nbsp;Gaoge Xu","doi":"10.1016/j.synbio.2025.08.013","DOIUrl":"10.1016/j.synbio.2025.08.013","url":null,"abstract":"<div><div><em>Lysobacter enzymogenes</em> is a beneficial soil bacterium renowned for its potent biocontrol properties, primarily attributed to antimicrobial secondary metabolites such as HSAF and WAP-8294A2, as well as specialized secretion systems. In this study, we investigate the post-transcriptional regulatory roles of the RNA chaperone Hfq in <em>L</em>. <em>enzymogenes</em> OH11 using an integrated multi-omics approach, combining transcriptomic, proteomic, and RNA-binding data. Our comprehensive analysis reveals that Hfq systemically regulates central metabolism and coordinates biocontrol-associated processes, including antimicrobial biosynthesis and secretion systems. Notably, Hfq extensively modulates multiple regulatory pathways involved in HSAF biosynthesis, a well-studied compound with potential applications in combating fungal and oomycete diseases. Additionally, we identify a set of Hfq-associated small RNAs. Through target prediction, we inferred that many of these sRNAs likely influence cellular functions and stress responses, reinforcing Hfq's role as a global regulator of bacterial physiology. These findings provide a systems-level understanding of Hfq's regulatory mechanisms in <em>L. enzymogenes</em>, offering valuable insights for optimizing its biocontrol potential.</div></div>","PeriodicalId":22148,"journal":{"name":"Synthetic and Systems Biotechnology","volume":"11 ","pages":"Pages 37-47"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simplified synthetic microbial community enhances resistance of crucian carp (Carassius auratus) to Aeromonas hydrophila infection through host immune activation","authors":"Xiaozhou Qi ,&nbsp;Yilin Zhang ,&nbsp;Zhongchen Sun ,&nbsp;Gaoxue Wang ,&nbsp;Fei Ling","doi":"10.1016/j.synbio.2025.10.011","DOIUrl":"10.1016/j.synbio.2025.10.011","url":null,"abstract":"<div><div>Bacterial diseases represent a major bottleneck in the sustainable development of aquaculture. The gut microbiota plays a vital role in host growth and health, including the enhancement of disease resistance. Although substantial progress has been made in elucidating the mechanisms of disease resistance in fish, the precise role of the gut microbiota in enhancing pathogen resistance in aquatic animals remains poorly understood. In this study, crucian carp (<em>Carassius auratus</em>) were used as a model to investigate the role of intestinal microbiota in modulating resistance to <em>Aeromonas hydrophila</em>. Individual crucian carp exhibited distinct clinical phenotypes following <em>A</em>. <em>hydrophila</em> infection. Specifically, significant differences were observed in the composition of the intestinal microbiota between fish displaying mild symptoms and those exhibiting severe phenotypic manifestations (α diversity: <em>p</em> &lt; 0.01; β diversity: <em>p</em> = 0.001). Fecal microbiota transplantation (FMT) experiments demonstrated that fish with mild symptoms conferred enhanced resistance to <em>A. hydrophila</em> when their intestinal contents were transplanted into other individuals (<em>p</em> = 0.006). Further microbial analysis identified <em>Cetobacterium</em> (<em>p</em> = 0.013), <em>Paraclostridium</em> (<em>p</em> &lt; 0.01), and <em>Pseudomonas</em> (<em>p</em> &lt; 0.01) as key differential taxa. A simplified microbial community comprising these three strains was subsequently constructed. Feeding experiments confirmed that administration of this community significantly improved host resistance to <em>A. hydrophila</em> (<em>p</em> &lt; 0.05) by activating intestinal immune responses and reinforcing the gut barrier. Overall, our findings underscore the potential of the microbial community as a novel strategy for disease prevention and control in aquaculture, providing a theoretical foundation for the development of microbiome-based therapies in fish health management.</div></div>","PeriodicalId":22148,"journal":{"name":"Synthetic and Systems Biotechnology","volume":"11 ","pages":"Pages 407-418"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiple Buster transposons from hAT superfamily displaying transposition activities in mammal cells","authors":"Zhongxia Guan ,&nbsp;Binqing Wang ,&nbsp;Bo Gao ,&nbsp;Shasha Shi ,&nbsp;Saisai Wang ,&nbsp;Han Wu ,&nbsp;Mohamed Diaby ,&nbsp;Cai Chen ,&nbsp;Xiaoyan Wang ,&nbsp;Chengyi Song","doi":"10.1016/j.synbio.2025.10.006","DOIUrl":"10.1016/j.synbio.2025.10.006","url":null,"abstract":"<div><div>TcBuster, a member of the <em>Buster</em> family within the <em>hAT</em> superfamily, has been engineered into an effective gene transfer tool for gene therapy applications. To diversify the toolkit available for efficient gene delivery, we conducted a bioinformatics analysis, which indicated that some <em>Buster (BT)</em> transposons exhibit signs of recent activity in Actinopterygii and Arthropoda species. Cell-based transposition assays demonstrated that endogenous transposases from <em>Armadillidium nasatum</em> (<em>AnBT</em>), <em>Hyles vespertilio</em> (<em>HvBT</em>), and <em>Lota lota</em> (<em>LlBT</em>) showed 47 %, 44 %, and 39 % transposition activity, respectively, in comparison to that of <em>piggyBac</em> transposons. Conversely, transposases from <em>Carcinoscorpius rotundicauda</em> (<em>CrBT</em>) and <em>Larimichthys crocea</em> (<em>LcBT</em>) presented minimal activity. Further assays confirmed that the 240 bp left and 126 bp right terminal sequences of the <em>AnBT</em> transposon are critical for maintaining transposition activity. In addition, <em>AnBT</em> exhibited the typical overproduction inhibition effect, reaching optimal activity at a 50 ng helper plasmid input, with both minimal (10 ng) and maximal (500 ng) doses of the donor plasmid. Notably, <em>AnBT</em>'s transposition efficiency was 63 % compared to that of <em>piggyBac</em> at peak activity levels. This evidence suggests that <em>AnBT</em> could be a promising alternative gene delivery vector for gene therapy and transgenesis.</div></div>","PeriodicalId":22148,"journal":{"name":"Synthetic and Systems Biotechnology","volume":"11 ","pages":"Pages 397-406"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced vitamin B6 production in engineered Escherichia coli via restricted mix-carbon feeding and pressure-controlled fermentation","authors":"Long Chen ,&nbsp;Miao-Miao Xia ,&nbsp;Hui-Na Dong ,&nbsp;Hao-Ran Ma ,&nbsp;Xu-Yang Huang ,&nbsp;Gong-Jin Shen ,&nbsp;Zhao-Xia Jin ,&nbsp;Lin-Xia Liu ,&nbsp;Da-Wei Zhang","doi":"10.1016/j.synbio.2025.09.004","DOIUrl":"10.1016/j.synbio.2025.09.004","url":null,"abstract":"<div><div>Pyridoxine (PN), a major commercial form of vitamin B₆, is mainly produced via chemical synthesis, raising environmental concerns. Microbial fermentation offers a greener alternative, but low biomass and titer limit industrial application. In this study, we developed an integrated strategy combining DO-stat restricted mix-carbon feeding with two-stage pressure-controlled fermentation conditions, and medium optimization to enhance cell growth and PN production in <em>Escherichia coli</em>. DO-stat feeding enabled dynamic regulation of oxygen and carbon sources, while a two-stage pressure-controlled (0.1 bar for 0–24 h, 0.2 bar thereafter) improved both growth and PN biosynthesis. Meanwhile, a novel medium (CRS-67), optimized via Taguchi design, increased shake flask PN titer by 275 mg/L, 75.5 % over CS medium. Under systematic fermentation optimization in a 5-L bioreactor, OD₆₀₀ reached 142.8 and PN titer reached 3.33 g/L—the highest reported level to date. This study presents a robust and scalable process for microbial PN production and offers insights for industrial biomanufacturing of vitamin B₆.</div></div>","PeriodicalId":22148,"journal":{"name":"Synthetic and Systems Biotechnology","volume":"11 ","pages":"Pages 76-84"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Harnessing synthetic biology for tetraterpenoid astaxanthin production: Recent advances and challenges","authors":"Yue Hou ,&nbsp;Ailin Guan ,&nbsp;Xuefen Fan ,&nbsp;Jiufu Qin","doi":"10.1016/j.synbio.2025.08.005","DOIUrl":"10.1016/j.synbio.2025.08.005","url":null,"abstract":"<div><div>Astaxanthin, a potent lipid-soluble ketocarotenoid, exists in various stereoisomeric, geometric isomeric, and esterified forms. Its unique molecular configuration and biological activity confer significant advantages for pharmaceutical applications and nutraceutical supplementation. While widely distributed in natural environments, particularly abundant in marine ecosystems, astaxanthin production via conventional methods fails to meet escalating market demands and consumer preference for natural products. Recent synthetic biology advances enable engineered microbial cell factories for astaxanthin production. Through precise genome editing and metabolic reprogramming, these systems offer a sustainable, efficient alternative to traditional synthesis of this high-value antioxidant. In this review, we highlight the latest advancements in constructing artificial cell factories for the production of astaxanthin. Specially, we systematically examine current breakthroughs in synthetic biology-enabled astaxanthin manufacturing, with emphasis on three dimensions: “point” (regulation of key enzymatic activity and expression levels), “line” (pathway-level spatial coordination to balance intermediate flux), and “plane” (system-level metabolic harmonization to address product toxicity and pathway-host metabolic incompatibility). We further discuss critical gaps requiring interdisciplinary innovation to realize the full potential of microbial cell factories in sustainable astaxanthin manufacturing production.</div></div>","PeriodicalId":22148,"journal":{"name":"Synthetic and Systems Biotechnology","volume":"11 ","pages":"Pages 309-316"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced PrrAB system activation and restricted farnesyl pyrophosphate diversion underlie high coenzyme Q10 accumulation in Rhodobacter sphaeroides HY01","authors":"Xinwei He ,&nbsp;Huangwei Wang ,&nbsp;Mindong Liang ,&nbsp;Weishan Wang ,&nbsp;Biqin Chen ,&nbsp;Dan Li ,&nbsp;Lixin Zhang ,&nbsp;Gao-Yi Tan","doi":"10.1016/j.synbio.2025.09.012","DOIUrl":"10.1016/j.synbio.2025.09.012","url":null,"abstract":"<div><div>The industrial <em>Rhodobacter sphaeroides</em> HY01 accumulates an exceptionally high level of coenzyme Q₁₀ (Q₁₀), but the underlying mechanisms remain incompletely understood. Given the central role of Q₁₀ in respiratory electron transport, previous observation of reduced expression of <em>cbb</em>_<em>3</em>-type cytochrome <em>c</em> oxidase genes in HY01 suggested a potential mechanistic link. In this study, we found that <em>cbb</em>_<em>3</em> oxidase activity in HY01 was only 21.8–32.8 % of that in the wild-type 2.4.1, and restoring this activity led to a 64.4 % decrease in Q₁₀ accumulation, demonstrating a strong inverse correlation. This correlation was found to be mediated by the activation of the PrrAB two-component regulatory system, which is negatively regulated by <em>cbb</em>_<em>3</em> oxidase. However, disruption of <em>cbb</em>_<em>3</em> oxidase in 2.4.1 alone was insufficient to reproduce the high Q₁₀ accumulation phenotype, indicating that additional factors may be required. Previous research also revealed restricted synthesis of geranylgeranyl diphosphate (GGPP) in HY01, which likely reduces the diversion of the Q₁₀ precursor farnesyl diphosphate (FPP). Reconstituting this metabolic constraint in wild-type strain, combined with fine-tuning of PrrAB system activation, resulted in up to a 218.0 % increase in Q₁₀ accumulation, achieving a level nearly identical to HY01. Combining mechanistic investigation and inverse metabolic engineering, this study demonstrates that the high Q₁₀ accumulation in HY01 results from the synergistic effects of enhanced PrrAB activation and restricted FPP diversion, providing new insights into the key factors underlying high-level Q₁₀ accumulation in <em>R</em>. <em>sphaeroides.</em></div></div>","PeriodicalId":22148,"journal":{"name":"Synthetic and Systems Biotechnology","volume":"11 ","pages":"Pages 172-180"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic engineering PETase reveals loop-region mutations for enhanced catalytic activity and thermal stability","authors":"Yuxin Han ,&nbsp;Shilong Xing ,&nbsp;Mingzhu Ding ,&nbsp;Ying Wang ,&nbsp;Wenhai Xiao ,&nbsp;Yixun Jiang ,&nbsp;Mingdong Yao","doi":"10.1016/j.synbio.2025.10.001","DOIUrl":"10.1016/j.synbio.2025.10.001","url":null,"abstract":"<div><div>Biodegradation of Polyethylene Terephthalate (PET) offer a strategic avenue for addressing the global plastic pollution crisis. However, the degradation performance of PET hydrolases remains a technological bottleneck for the industrial realization of plastic biodegradation. In this study, we employed an integrated strategy combining semi-rational design and directed evolution to discover new mutation sites (N114, N205, N233 and S269) that enhance the catalytic activity and thermostability of <em>Ideonella sakaiensis</em> PETase (<em>Is</em>PETase). Subsequently, through the combined design of newly discovered mutation sites, we screened the novel quadruple mutant (N114I/N205K/N233K/S269V, named QM-PETase-2), which exhibited a 4.9-fold increase in catalytic efficiency and a Δ<em>T</em>_m of +12.4 °C. Interestingly, the four newly discovered mutation sites are all located in the loop region of the enzyme structure, which might play a crucial role on the structural stability of enzyme. Also, molecular dynamics simulations revealed that the QM-PETase-2 exhibited a more stable structure and an expanded substrate-binding cleft, which would facilitate the binding of the polymer PET substrate. Especially, the newly quadruple mutation sites were introduced into three reported high-performance PETase mutants FAST-PETase, PA-PETase, and DepoPETase. The obtained combined mutants, named QMFAST-PETase, QMPA-PETase, and QM-DepoPETase, demonstrated higher activity and thermal stability, indicating that the newly discovered mutations are universal for improving the performance of PETase. This research would be helpful in guiding the optimization and development of PETase.</div></div>","PeriodicalId":22148,"journal":{"name":"Synthetic and Systems Biotechnology","volume":"11 ","pages":"Pages 419-429"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Amplicon-based prediction of secondary metabolic potential of microbiomes facilitates natural product discovery","authors":"Zhen-Yi Zhou ,&nbsp;Qun-Jian Yin ,&nbsp;Buddha Bahadur Basnet ,&nbsp;Zi-Yang Li ,&nbsp;Gen Li ,&nbsp;Mahmoud Emam ,&nbsp;Qi-Hao Wu ,&nbsp;Hong Wang ,&nbsp;Bin Wei","doi":"10.1016/j.synbio.2025.10.012","DOIUrl":"10.1016/j.synbio.2025.10.012","url":null,"abstract":"<div><div>The rapid exploration of natural products not only expands chemical diversity but also plays a vital role in drug discovery by identifying bioactive agents (e.g., antibiotics), revealing novel biological mechanisms, and providing new therapeutic opportunities. However, traditional techniques require extensive resources to screen and prioritize bacteria capable of producing valuable compounds from complex environmental samples. Here, we introduce the PSMPA (<strong>P</strong>redicting the <strong>S</strong>econdary <strong>M</strong>etabolism <strong>P</strong>otential using <strong>A</strong>mplicons) pipeline, designed to assess the secondary metabolic potential of microbiomes by estimating the abundance of biosynthetic gene cluster (BGC) classes based on 16S rRNA gene amplicons. This approach facilitates early-stage selection of samples and strains with high potential for novel compound production. We applied PSMPA to microbiome samples from marine environments (seawater, mangrove sediment, and intertidal flat sediment), leading to the identification of a promising <em>Marinobacterium</em> strain YM272 and the discovery of maripanthiones, a new class of sulfur-containing natural products. By enabling early identification of promising strains or samples, PSMPA accelerates novel natural product discovery and enhances the utility of amplicon sequencing for functional analysis. The web version of PSMPA is available at <span><span>https://www.psmpa.net/</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":22148,"journal":{"name":"Synthetic and Systems Biotechnology","volume":"11 ","pages":"Pages 385-396"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural and functional insights into the iminium ion intermediate in AsKslB-mediated Pictet-Spengler reaction","authors":"Yan-Bin Teng ,&nbsp;Zhi Qiao ,&nbsp;Chunya Xie ,&nbsp;Xiaona Yang ,&nbsp;Xinyu Liu ,&nbsp;Zhengrong Zou ,&nbsp;Yunchang Xie ,&nbsp;Xuan Zhang ,&nbsp;Qi Chen","doi":"10.1016/j.synbio.2025.09.017","DOIUrl":"10.1016/j.synbio.2025.09.017","url":null,"abstract":"<div><div>Pictet-Spengler (PS) reactions are pivotal in the biosynthesis of bioactive alkaloids and pharmaceuticals, yet key structural details underlying their enzymatic catalysis remain insufficiently understood. We identified AsKslB from <em>Actinosynnema</em> sp. ALI-1.44 as a Pictet-Spenglerase with broad substrate scope that catalyzes the stereoselective condensation of <span>l</span>-tryptophan (<span>l</span>-Trp) and α-ketoglutarate (α-KG) to form kitasetalic acid (KA), a tetrahydro-β-carboline (THβC). High-resolution crystal structures of apo, substrate-, intermediate-, and product-bound forms elucidate the full catalytic trajectory and key residues. Crucially, the elusive iminium ion intermediate (IM-1) and a synchronously released water molecule are captured, providing direct structural evidence for the initiating cyclization step of Pictet-Spengler reaction. Glu276 undergoes conformational changes essential for catalysis. These findings offer detailed mechanistic insights into Pictet-Spenglerase function and establish AsKslB as a promising biocatalyst for stereoselective <em>N</em>-heterocycle synthesis.</div></div>","PeriodicalId":22148,"journal":{"name":"Synthetic and Systems Biotechnology","volume":"11 ","pages":"Pages 247-255"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145324732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Malic enzyme-based system for transhydrogenation between nicotinamide cofactors","authors":"Haizhao Xue ,&nbsp;Yinghan Hu ,&nbsp;Aabid Manzoor Shah ,&nbsp;Xueying Wang ,&nbsp;Xiaojia Guo ,&nbsp;Yanzhe Huang ,&nbsp;Zongbao K. Zhao","doi":"10.1016/j.synbio.2025.08.009","DOIUrl":"10.1016/j.synbio.2025.08.009","url":null,"abstract":"<div><div>The nicotinamide cofactors including nicotinamide adenine dinucleotide (NAD) and its phosphate (NADP) play important roles in facilitating redox reactions for energy metabolism and biosynthesis. To expand the cofactor menu, a non-natural cofactor nicotinamide cytosine dinucleotide (NCD) has been introduced recently. The reduced forms of these cofactors carry reducing equivalents that are essential for cellular metabolism. However, there is a long standing challenge to rationally transfer reducing equivalent from one cofactor to another, albeit such process is highly demanding in metabolic engineering. This study develops a new approach based on malic enzyme (ME)-mediated transhydrogenation to enable reducing equivalents exchange among different cofactors. We used wild-type ME, MaeB and an engineered ME∗ that favors NAD, NADP and NCD, respectively, to demonstrate such conversions. When an <em>in vitro</em> system initiated with equal amount of NADH and NCD in the presence of ME, ME∗ and excess amount of pyruvate was held for 2 h, up to 65 % NADH was consumed and 57 % NCDH was generated. When implemented into NCD self-sufficient <em>Escherichia coli</em> cells, the system directed reducing equivalents toward NCDH-linked formation of lactate. Overall, this work offers an effective strategy to regulate intracellular reducing equivalents that may serve as a novel tool for metabolic engineering and synthetic biology.</div></div>","PeriodicalId":22148,"journal":{"name":"Synthetic and Systems Biotechnology","volume":"11 ","pages":"Pages 10-18"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144933821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}