Curated Optogenetic Publication Database

Abstract: Toll-like receptors (TLRs) are single-pass transmembrane proteins that initiate innate immune responses through recognition of pathogen-associated molecular patterns, including lipopolysaccharide, flagellin, and microbial nucleic acids. In mammals, TLRs are expressed in both immune and non-immune cells, where they activate cytokine expression through the myeloid differentiation primary response 88 (MyD88) signaling pathway and subsequently engage the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) or interferon regulatory factor 3 / interferon regulatory factor 7 (IRF3/IRF7) pathways. To enable optical control of TLR function, the extracellular domains of several homodimeric TLRs, including TLR3, TLR4, and TLR5, are replaced with the photosensory core module of the bacterial phytochrome DrBphP. The resulting chimeric receptors activate the NF-κB and IRF3/IRF7 pathways in mammalian cells in a far-red-light-dependent manner. The MyD88 pathway is further reprogrammed to induce caspase activation instead of cytokine production, thereby creating a synthetic system that links TLR stimulation to caspase signaling. This strategy establishes a versatile optogenetic platform for far-red-light control of innate immune and cell death pathways.

Abstract: Cell therapy holds great promise for cancer immunotherapy, but its clinical efficacy is severely hindered by poor post-transplant cell survival, low homing efficiency, and host immune clearance. To address these challenges, this study develops a novel light-controlled immunotherapy strategy that integrates a red/far-red light genetic switch with single-cell encapsulation engineering. The red/far-red light (660/730 nm) reversible regulatory system enables precise spatiotemporal control over the expression of therapeutic proteins in engineered cells (e.g., CAR-T or engineered HEK 293T cells), allowing on-demand activation of anti-tumor immune responses. On this basis, a mild enzyme-mediated single-cell encapsulation technique is further employed to rapidly form a protective hydrogel coating in situ on the cell surface, thereby enhancing the survival of transplanted cells under hostile in vivo microenvironments. This strategy combines precise gene expression regulation with physical protection, improving therapeutic outcomes without the need for genomic modification of the cells. It provides a new paradigm for developing safe, controllable, and efficient cancer immunotherapy. Key features • Using a 660/730 nm red/far-red light reversible switch, deep tissue penetration enables spatiotemporal precise control of tumor-targeted therapeutic proteins. • Achieving rapid and gentle in situ gelation encapsulation of single-cell surfaces through HRP-pHLIP membrane anchoring and HA-dopamine enzymatic crosslinking. • Targeted strategies to overcome post-transplant hypoxia, inflammatory stress, and pulmonary first-pass entrapment, physically enhancing early cell survival prior to reaching the target tissue. • This experimental protocol requires at least three days.

Abstract: Here we introduce OpenEvo, a fully open-source, low-cost turbidostat platform for automated continuous culture and directed evolution experiments. Existing tools are expensive, complex, or lack open-source hardware; OpenEvo addresses this gap with a complete, fully automated evolution platform with detailed, illustrated construction instructions for beginners, open-source software and firmware, priced around $300. An optional PC-based interface offers enhanced functionality, including remote access, programmable evolution cycles, programmable LED stimulation, and a data visualization tool. OpenEvo can cycle through three types of media for positive, negative, and neutral selection conditions, supporting a wide range of experimental designs. We validate the use of OpenEvo by evolving Haloferax volcanii to grow from 15% to 12% salt over ~150 cycles, ~1,000 hours. Evolved cells grew 55% faster than wild-type at 12% salt. Whole-genome sequencing of adapted cells found SNPs and large deletions. We also demonstrate positive and negative selection using the OpenEvo LEDs to drive optogenetics via a Phytochrome B-based optogenetic tool, with light as the selection stimulus during over 4000 hours of growth. OpenEvo lowers the technical and cost barriers for continuous evolution experiments, serves as a teaching tool, and is designed to grow an open community of users who share modifications.

Abstract: Cancer is increasingly recognized as a disease of the dysregulated epigenome; however, current epi-drugs are blunt, systemically toxic instruments. Catalytically dead CRISPR nucleases (dCas9) linked to chromatin effectors have now made it possible not only to write and erase epigenetic marks at specified loci without double-strand breaks but also to add an element of optogenetics, or reversible and light-encoded control over the timing and localization of the editors. In this review, the technological underpinnings of light-controlled CRISPR-dCas9 epigenome editing, which include architectures of dCas9 scaffold and guide, blue-to-near-infrared photoswitches, and high-gain epigenetic effector designs, are synthesized, and viral, non-viral, and stimuli-responsive delivery platforms, which have to be co-optimized with clinical light interfaces, are discussed. We then outline four functional routes by which opto-epigenome editors may be used therapeutically in cancer: tumor suppressor reactivation; oncogene and super-enhancer repression with metabolic rewiring; control of cancer stem cell differentiation; and immunomodulation of the tumor microenvironment. Lastly, a translational roadmap is defined in terms of preclinical model tiers, biomarker strategies, regulatory and manufacturing factors, and future directions, including NIR and bioluminescent actuation, implantable μLED devices, and AI-guided closed-loop illumination. Together, these aspects constitute design principles for advancing light-addressable epigenome editors toward first-in-human studies and for integrating them into combination regimens as a new class of precision cancer therapeutics.

Abstract: Optogenetics represents a promising frontier in precision cancer therapy by enabling spatiotemporal control over cellular behavior. However, its clinical application is limited by inefficient delivery of optogenetic components and poor tissue penetration of visible light. Recent advances in nanotechnology offer solutions to these challenges. Nanoscale drug delivery systems enhance the targeted delivery of optogenetic tools, while light-conversion nanomaterials enable deep-tissue activation. Besides, the integration of nanotechnology with optogenetics further facilitates the development of engineered living therapeutics, including immune cells and bacteria, allowing programmable and localized antitumor responses. Despite promising preclinical progress, key challenges remain in long-term biosafety, immunogenicity, and precise light dosing. Future progress will depend on interdisciplinary efforts combining biocompatible nanomaterials, protein engineering, and artificial intelligence to advance clinically viable optogenetic therapies and pave the way toward personalized cancer treatment. Collectively, the synergistic integration of optogenetics and nanotechnology holds potential for overcoming longstanding barriers in cancer treatment, paving the way for precision cancer therapeutics.

Abstract: Inducible expression of endogenous and foreign genes has been a pivotal driving force behind a lot many seminal breakthroughs in biotechnology. Synthetic biology, a very promising field, largely relies on transgene expression platforms which facilitate convenient and conditional regulation. Optogenetic approaches that exploit light to steer biological events, e.g., gene expression, with excellent spatiotemporal control, are often more precise compared to chemical induction. Light being an omnipresent environmental stimulus, serves as the ideal cue, and enables high spatiotemporal accuracy with respect to gene expression. In this review, we focus on different elements relevant to light-inducible gene expression - light-responsive promoters, light-regulated transcription factors, and photocaged inducers. Using light as a binary input function, we explore the essence of logic gates towards the development of gene expression circuits - thereby understanding the entanglement between optogenetics and synthetic biology. We primarily focus on prokaryotes, but also draw comparisons with analogous eukaryotic gene expression systems.

Abstract: Glycosylation plays a pivotal role in regulating diverse biological processes. However, the lack of tools capable of controlling the spatiotemporal dynamics of glycosylation has largely hindered its functional elucidation. Here, we introduce an optogenetic approach that employs red/far-red light to dynamically and reversibly control the plasma membrane localization of O-linked N-acetylglucosamine transferase (OGT) in living systems. Red-light-induced translocation of OGT suppresses insulin signaling in both cells and mice. Glycoproteomic and phosphoproteomic analyses reveal a global impact of OGT-mediated glycosylation on signal transduction. Moreover, using protein semisynthesis, cell-based assays, and molecular dynamics simulations, we demonstrate that red-light-induced O-GlcNAcylation of WNK1 at S1949 inhibits downstream cell volume response signaling pathways by suppressing WNK1 biomolecular condensate formation. Together, our findings provide a valuable tool to modulate subcellular O-GlcNAcylation and control cellular signaling in living systems, with broad applicability to the study of glycosylation in cells.

Abstract: Optogenetics which involves the use of light to control cell functions on a genetic level has found utility in studying cell physiology, biomaterials and metabolic engineering. S. cerevisiae is an industrially relevant model organism that is used in many applications, but due to the large number of genes required and issues relating to cross-activation between different colours, optogenetics for different wavelengths of light have not been multiplexed in S. cerevisiae. In this paper, we develop a compact red light responsive optogenetic system for S. cerevisiae that requires only a single gene and no exogenous cofactors. Through engineering modular protein domains, we reduce the cross-activation of our system by blue light. We integrate our red light optogenetic system with EL222 blue light optogenetics to establish dual channel optogenetics in S. cerevisiae and demonstrate its utility for engineering biology through the light-based control of flavonoid luteolin synthesis and flocculation for ease of product extraction. We also demonstrate our system's potential for the development of living materials by producing dual-coloured optogenetic patterns using S. cerevisiae. This work expands optogenetic applications in S. cerevisiae from single-light to multi-light systems, introducing the potential to multiplex different colours of light for dynamic, orthogonal control of separate cell processes.

Abstract: Methylotrophic yeasts such as Pichia pastoris are widely used for heterologous protein production because they contain strong and tightly regulated promoters. However, the use of methanol as an inducer presents several practical challenges, including toxicity, flammability, high oxygen demand during fermentation, and increased production costs. To overcome these limitations, researchers have been working on redesigning the AOX1 regulatory system and developing alternative induction strategies that do not rely on methanol. One promising approach is optogenetics, which uses light to control gene expression in a non-invasive way. These systems rely on light-sensitive proteins such as phytochromes, cryptochromes, LOV-domain proteins, and UVR8, allowing gene activity to be regulated in a precise and reversible manner without adding chemical inducers to the culture medium. This review brings together key advances in yeast optogenetics, with a focus on the EL222 system, highlighting its implementation for light-controlled heterologous protein production in P. pastoris and its broad application in synthetic biology and metabolic engineering in Saccharomyces cerevisiae. The growing versatility and scalability of EL222-based circuits highlight their potential to reshape both fundamental research and industrial bioprocessing through safer, more controllable, and energy-efficient gene regulation strategies.

Abstract: Cells in many naturally occurring organisms routinely cooperate to control their extracellular pH in a dynamic and reversible manner, but this capability has been underexplored in synthetic biology. Here, we sought to engineer a microbial system that switches between two states -high and low extracellular pH- with minimal human intervention. We accomplished this by combining: (1) a genetic circuit that produces recombinant urease under the control of a light-inducible promoter; (2) a degradation tag on urease to accelerate the high-to-low pH transition; and (3) optimization of several environmental factors, including media composition, replenishment rate, and light exposure patterns. The system raises the pH when urease is produced and hydrolyzes urea in the media to produce ammonia; it lowers the pH as a byproduct of the cell's native metabolism when urease production ceases. We demonstrate that the optimized system cycles continuously for up to 14 days with minimal performance loss. Overall, our system demonstrates synthetic pH control in an engineered living system and highlights challenges and potential solutions for using such systems outside of the context of typical laboratory manipulation.

Abstract: In developmental biology, cellular events must be orchestrated at precise times and locations in the embryo. Many classic discoveries were achieved by perturbing developmental organization using approaches ranging from tissue transplantation to local, acute heat shock. A growing suite of optogenetic tools is now available with fine spatiotemporal control, opening the door to perturbation experiments with unprecedented precision. Here we highlight these tools, review their application in developmental contexts, and discuss their current challenges and future promise.

Abstract: Tumor recurrence, metastasis, and therapeutic resistance remain major challenges in oncology, driving the need for advanced therapeutic strategies with improved precision and controllability. Optogenetics, which enables light-mediated regulation of cellular functions, has emerged as a promising modality for cancer therapy by offering unparalleled spatiotemporal precision. This capability allows dynamic control of intracellular signaling and transgene expression, enabling selective targeting of malignant cells while minimizing damage to surrounding tissues. However, clinical translation is hindered by key challenges, including inefficient in vivo delivery of optogenetic components, limited tissue penetration of activating light, and suboptimal performance of existing tools. Addressing these barriers requires a convergence of molecular engineering and materials science, wherein advanced biomaterials play a critical role in enabling gene delivery and overcoming tissue-penetration limitations in complex tumor environments. In this review, we provide a comprehensive oriented overview of optogenetics in oncology. We first analyze the molecular mechanisms and engineering principles of representative optogenetic tools, with a focus on LOV- and CRY2-based systems. We then highlight recent advances in biomaterial-assisted optogene delivery and light delivery strategies, emphasizing their material-dependent mechanisms that enable precise spatiotemporal control in vivo. Furthermore, we summarize emerging preclinical applications in cancer immunotherapy, gene regulation, and intracellular signaling control. Finally, we discuss key challenges in biosafety, kinetic optimization, and clinical scalability, and outline future directions that integrate optogenetics with functional materials and intelligent design to realize clinically viable platforms. This review aims to provide a framework for the development of clinically viable optogenetic platforms for next-generation cancer therapy.

Abstract: The bacterial stress response is an intricately regulated system that plays a critical role in cellular resistance to drug treatment. Stress response genes are organized into networks with transcriptional regulators controlling downstream genes, but how variability in these regulators affects the downstream response remains unclear. We investigate how heterogeneity in the virulence regulator PhoP propagates to its diverse regulon. Using optogenetic control of PhoP expression and information theory, we find that downstream genes differ in mean expression, sensitivity to PhoP levels, and signal transmission reliability. These response functions also vary between individual cells, increasing population heterogeneity. We tie these variations to cell survival upon exposure to a clinically relevant antimicrobial peptide, showing that while high expression of the PhoP-regulon gene pmrD provides protection, cell survival is best determined by the integrated PhoP and pmrD expression levels. Our findings demonstrate that heterogeneous expression of stress response regulators has clear consequences for bacterial stress survival.

Abstract: In this study, we describe a rationally designed light-inducible RNA-releasing protein (LIRP) capable of inhibiting mRNA translation in the dark while permitting gene expression upon exposure to blue or ambient light. This LIRP-dependent gene switch is compatible with various delivery routes of gene- and cell-based therapy, such as subcutaneous implantation of microencapsulated light-sensitive cells or expression in various light-accessible body sites using single adeno-associated virus (AAV) vectors. To exemplify a gene therapy approach that directly harnesses ambient light as a natural illumination source to induce therapeutic action, we show how intradermal delivery of AAV2 vectors carrying a LIRP-regulated gene switch controlling murine thymic stromal lymphopoietin expression was effective in enabling light-dependent prevention and treatment of diet-induced obesity. To describe another therapeutic scenario, we engineered AAV2 vectors for LIRP-dependent expression of Vascular endothelial growth factor (VEGF) inhibitors for the treatment of retinal neovascular diseases. Upon intravitreal delivery into mice suffering from wet macular degeneration, VEGF inhibitors were constantly produced when animals were exposed to daylight, but therapeutic actions could be flexibly interrupted either by exposure to dark environments or by administration of a selective blue light filter at any point in time. When compared to conventional treatment strategies based on constitutive VEGF inhibition over the course of 3 months, we show that a regulated gene therapy approach through LIRP-dependent optogenetics was advantageous in maintaining a normal retina thickness. This work not only provides a valuable addition to the optogenetic toolbox but also offers a perspective to translate light-dependent gene switches toward therapeutic usage.

Abstract: The cytoskeleton is a dynamic intracellular network that governs cell shape, migration, division, and mechanotransduction. Precise spatiotemporal control of cytoskeletal regulation is essential for understanding how these processes are coordinated in physiology and disease, yet conventional pharmacological and genetic approaches often lack sufficient resolution or reversibility. Optogenetic technologies provide a powerful alternative by enabling light-controlled, noninvasive manipulation of cytoskeletal regulators with high temporal precision and subcellular specificity. This review summarizes recent advances in genetically encoded optogenetic tools for interrogating cytoskeletal dynamics. We discuss core design strategies, including allosteric regulation, light-induced oligomerization, heterodimerization, and dissociation, and highlight representative applications targeting actin filaments, microtubules, and upstream signaling pathways such as Rho family GTPases. We conclude by outlining current limitations and emerging directions, including improved tissue penetration, reduced phototoxicity, and multiplexed optical control, which are expected to further expand the utility of optogenetics in cytoskeleton research.

Abstract: Light-inducible heterodimerization systems offer precise, reversible control of protein interactions in living cells. Leveraging the high tissue-penetration of red/far-red light, the MagRed system, composed of a bacteriophytochrome Deinococcus radiodurans BphP (DrBphP) and its engineered affibody binder Aff6, achieves robust photoswitchable dimerization. This makes MagRed well-suited for in vivo and deep-tissue optogenetic application. However, the structural mechanism underlying Aff6's photo-state-specific recognition of DrBphP remains elusive. Here, we combine solution NMR spectroscopy, surface plasmon resonance (SPR), molecular docking and mutational analysis to elucidate the light-dependent interaction between a monomeric photosensory core module of DrBphP (DrBphP-PCMmono) and Aff6. We show that DrBphP-PCMmono alone is sufficient for light-inducible heterodimerization with Aff6, exhibiting a ∼ 23-fold affinity difference between the Pfr and Pr states. NMR titration reveals that Aff6 binds primarily to the PHY domain and the C-terminal region of the helical spine. Furthermore, docking and mutagenesis identify a key aromatic interaction (involving F327/H334 of DrBphP and F18 of Aff6) as the molecular basis for this conformational selectivity. Additionally, Aff6 binding stabilizes the Pfr state and retards the Pfr-to-Pr reversion of DrBphP-PCMmono. These findings not only provide critical structural insight into MagRed function but also establish a foundation for rationally engineering next-generation phytochrome-based optogenetic tools.

Abstract: Inflammatory bowel disease demands spatiotemporally precise drug delivery, yet the variable gut redox environment limits stimuli-responsive nanocarriers. Here we report a living biohybrid platform in which optogenetically engineered Shewanella oneidensis MR-1 is electrostatically conjugated with azo-bond covalent organic frameworks (TA-COFs) loaded with anti-inflammatory drugs magnolol or 4-iodobenzoic acid. Under intestinal conditions and non-invasive red-light irradiation (660 nm), light-induced restoration of the metal-reducing pathway promotes extracellular electron transfer, thereby cleaving azo bonds in the COF. This triggers rapid structural disassembly and a 2.8-fold increase in drug release. Although wild-type Shewanella is thermally inactivated at 37 °C and cannot utilize abundant colonic acetate, expression of heat-shock genes (groES/thiF) and an acetate-to-TCA pathway (ato1/ato2/gltA) confers 37 °C tolerance and robust metabolism in the gut. In DSS-induced colitis mice, oral administration of the biohybrid significantly alleviates inflammation, restores epithelial barrier integrity, rebalances gut microbiota (enrichment of Akkermansia, Muribaculaceae, and Lachnospiraceae). This work presents a generalizable strategy for constructing electroactive living composites by integrating microbial electron generation with stimuli-responsive nanomaterials, offering a new paradigm for light-programmed smart therapeutics and programmable living materials in biomedical applications.

Abstract: Evolving dynamic, multi-state, and computational protein functionalities is challenging because it requires selection pressure on all the states of a protein of interest (POI) and the transitions between them. To create a continuous directed evolution paradigm for such properties, we genetically engineered budding yeast for optogenetic input to switch a POI "on" and "off," which, in turn, controls a Cdk1 cyclin that is essential for one cell-cycle stage but detrimental for another. The method, "optovolution," generates dynamic selection pressure on POI cycling at the timescale of tens of minutes. We used it to evolve 19 new variants of the LOV transcription factor El222, including in vivo green-light-responsive variants allowing LOV color-multiplexing. Evolving the PhyB-Pif3 optogenetic system, we discovered that loss of YOR1 makes supplementing phycocyanobilin (PCB) unnecessary. Finally, we demonstrated the generality of the method by evolving a non-light-responsive AND gate (PEST-rtTA). Optovolution makes difficult-to-engineer protein functionalities continuously evolvable.

Abstract: As an interdisciplinary frontier integrating optical technologies and genetic principles, optogenetics enables precise spatiotemporal control of gene expression and neuronal activity via light-sensitive molecular assemblies, thereby driving transformative advancements in biomedical fields. Red/far-red light optogenetic tools, by virtue of the advantages of long wavelengths, have emerged as powerful platforms for deep-tissue manipulations for both basic researches and clinical applications. Although a number of in-depth studies on various red/far-red light optogenetic tools and their biomedical applications have been published, there has not yet been a comprehensive review that systematically summarizes the advancements of diverse researches on this type of optogenetics. This article systematically delineates the technology of red/far-red light optogenetics, focusing on the molecular mechanisms and biomedical applications of two core photoreceptor protein families: phytochromes and channelrhodopsins. Phytochromes distributed in plants, bacteria and fungi undergo reversible red/far-red light-driven conformational conversion, initiating downstream signaling cascades that support various optogenetic technologies. Channelrhodopsins, originally microalgal blue-light-gated cation channels, are engineered into red-shifted variants, enabling rapid and non-invasive red/far-red light-controlled neuronal excitability manipulation at precise spatiotemporal resolution. The representative case studies of applications of phytochromes-based optogenetic tools in gene editing, transcriptional regulation, light-gated drug delivery and deep tissue imaging and diagnosis; as well as applications of red-shifted channelrhodopsins-based optogenetic tools in spatiotemporally precise neuromodulation are discussed in detail. Moreover, the main technical challenges in the utilization of red/far-red light optogenetic tools are analyzed. With continuous advancements of wavelength-optimized actuators and closed-loop control architectures, red/far-red light optogenetic techniques are poised to drive multidisciplinary convergence, offering unprecedented tools for decoding cellular dynamics and accelerating therapeutic discoveries.

Abstract: In plants, the regulation of transgene transcription is typically achieved using chemical agents. A safe alternative to chemically induced systems may be optogenetic systems. The BphP1-QPAS1 system has distinct advantages over other optogenetic systems, as it is activated by near-infrared (NIR, 780 nm) light, which is beyond the spectrum of plant photoreceptors. This system is based on the use of a split transcription factor (TF), consisting of the DNA-binding and dimerization domains of the yeast TF Gal4, fused to the QPAS1 component, along with the transactivation domain VP16 fused to BphP1. Under NIR light, BphP1 interacts with QPAS1, leading to the formation of the functional TF Gal4-VP16. A primary obstacle to using optogenetic systems in plants is their undesired activation under white light, which is vital for normal plant growth. A potential solution to this issue is temporarily removing one component of the split TF from the nucleus under white light. We modified the BphP1-QPAS1 system to activate reporter gene expression in Nicotiana benthamiana leaves using NIR light. We combined BphP1-QPAS1 with several variants of LOV domain-containing proteins activated by blue light (460-480 nm). The best results were achieved by combining the BphP1-QPAS1 system with the AsLOV2 domain, which carries the degron sequence RRRG at the C-terminal Jα helix and initiates the degradation of the chimeric protein NES-Gal4-QPAS1-AsLOV2-RRRG under white light. This modification induced the BphP1-QPAS1 system in tobacco leaves only under NIR light, but not in the dark or under white light. We believe that, in the future, the BphP1-QPAS1 system could be applied to enhance plant resistance to adverse environmental conditions, pests, and viral diseases.

Abstract: Light is a pivotal environmental signal regulating diverse plant developmental and physiological processes, including seed germination, hypocotyl elongation, phototropism, metabolite biosynthesis, stress resistance, temperature response, and circadian rhythms. Multiple signal transduction pathways of ultraviolet, blue light, and red/far-red light as well as related protein interaction networks in plants have been identified. Deciphering the mechanisms of light perception and signal transduction is of great significance to crop breeding and optogenetic manipulation. Structural biology has profoundly advanced the studies of light signal transduction by elucidating high-resolution three-dimensional (3D) structures of photoreceptors and their downstream signaling components. These studies uncover the molecular basis underlying perception and transduction of different light signals by plants. This review summarizes key structural findings of plant light signal transduction, highlighting the architectures and molecular functions of photoreceptors and associated signaling factors. We also outline the mechanisms underlying photoreceptor activation, inhibition, and regulatory interactions within light signaling networks and discuss the challenges in this field.

Abstract: Microbial optogenetic tools can regulate gene expression with spatial and temporal precision, offering excellent potential for single-cell resolution studies. However, bacterial optogenetic systems have primarily been deployed for population-level experiments. It is not always clear how these tools perform in single cells, where stochastic effects can be substantial. In this study, we focus on optogenetic Cre recombinase and compare the performance of three variants (OptoCre-REDMAP, OptoCre-Vvd, and PA-Cre) for their population-level and single-cell activity. We quantify recombination efficiency, expression variability, and activation dynamics using reporters which produce changes in fluorescence or antibiotic resistance following light-induced Cre activity. We find that optogenetic recombinase performance can be reporter-dependent. Further, single-cell analysis reveals highly heterogeneous activity, with substantial variation in the efficiency and timing of recombinase activity from cell to cell. These findings suggest important criteria for selecting optogenetic recombinases and indicate areas for optimization to improve single-cell capabilities of bacterial optogenetic tools.

Abstract: Synthetic microbial consortia (SMCs) represent a paradigm shift from monocultures to multi-strain systems that leverage ecological interactions for enhanced environmental adaptation and bioproduction. This review systematically sorts out engineering strategies for constructing stable SMCs, focusing on three core principles regarding host selection based on obligate mutualism (e.g., auxotrophs), pathway modularization to resolve metabolic conflicts, and dynamic regulation using tools like quorum sensing and optogenetics. We demonstrate the efficacy of SMCs in diverse applications including high-value compound synthesis and lignocellulosic biomass conversion through consolidated bioprocessing and inhibitor mitigation. SMCs enabling advanced functions in engineered living materials, environmental remediation, and biomedical innovation via division of labor are also described. Despite such progress, challenges in scalability and real-time control of SMCs under industrial conditions remain. We conclude that SMCs serve to bridge evolutionary ecology and biotechnology, offering robust solutions for sustainable biomanufacturing and beyond.

Abstract: Bis(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) plays a crucial role in bacterial signaling pathways, allowing bacterial cells to respond to various environmental stimuli. The prevalence of c-di-GMP and its potential applications underscore the necessity for developing tools and methods to regulate intracellular c-di-GMP levels. Optogenetic control of c-di-GMP dynamics is particularly attractive because it enables tunable and spatiotemporal regulation of c-di-GMP metabolism. The development of sensitive optogenetic control systems requires highly active, light-responsive c-di-GMP synthases. Here, we report an engineered, highly active photosensitive c-di-GMP synthase, BphS-13. This engineered c-di-GMP synthase was developed from a near-infrared (NIR) light-activable bacteriophytochrome c-di-GMP synthase, BphS, using a three-step directed evolution process that included error-prone PCR, in vitro homologous recombination, and site-directed mutagenesis. After two rounds of this directed evolution strategy, we generated a BphS variant with 13 mutations, referred to as BphS-13. The diguanylate cyclase (DGC) activity of BphS-13 was approximately 13 times higher than that of the original BphS, and it exhibited tightly regulated DGC activity in response to NIR light with minimal leakage in the dark. We then demonstrated the effectiveness of BphS-13 in controlling biofilm dynamics. Overall, this study highlights BphS-13 as a highly active and photosensitive tool for optogenetic applications in biotechnology and suggests its future potential application in mammalian systems for precise control of gene expression, particularly given the lack of native c-di-GMP signaling pathways in mammalian cells.

Abstract: Despite its central role in signaling, the influence of protein architecture on phytochrome structure and reactivity remains poorly understood. Here, we test how removal of the PHY domain reshapes the far-red-absorbing Pfr energy landscape and photochemical branching in the knotless phytochrome All2699g1g2.