Synthetic translational coupling system for accurate and predictable polycistronic gene expression control in bacteria.

Precise and predictable genetic elements are required to address various issues, such as suboptimal metabolic flux or imbalanced protein assembly caused by the inadequate control of polycistronic gene expression in bacteria. Here, we devised a synthetic biopart based on the translational coupling to control polycistronic gene expression. This module links the translation of genes within a polycistronic mRNA, maintaining their expression ratios regardless of coding sequences, transcription rate, and upstream gene translation rate.

Dynamic control of the plasmid copy number maintained without antibiotics in Escherichia coli.

Background: Manipulating the gene expression is the key strategy to optimize the metabolic flux. Not only transcription, translation, and post-translation level control, but also the dynamic plasmid copy number (PCN) control has been studied. The dynamic PCN control systems that have been developed to date are based on the understanding of origin replication mechanisms, which limits their application to specific origins of replication and requires the use of antibiotics for plasmid maintenance.

Synthetic redesign of Escherichia coli W for faster metabolism of sugarcane molasses.

Background: Sugarcane molasses, rich in sucrose, glucose, and fructose, offers a promising carbon source for industrial fermentation due to its abundance and low cost. However, challenges arise from the simultaneous utilization of multiple sugars and carbon catabolite repression (CCR). Despite its nutritional content, sucrose metabolism in Escherichia coli, except for W strain, remains poorly understood, hindering its use in microbial fermentation.

Tunable translation-level CRISPR interference by dCas13 and engineered gRNA in bacteria.

Although CRISPR-dCas13, the RNA-guided RNA-binding protein, was recently exploited as a translation-level gene expression modulator, it has still been difficult to precisely control the level due to the lack of detailed characterization. Here, we develop a synthetic tunable translation-level CRISPR interference (Tl-CRISPRi) system based on the engineered guide RNAs that enable precise and predictable down-regulation of mRNA translation. First, we optimize the Tl-CRISPRi system for specific and multiplexed repression of genes at the translation level.

CRISPRi-mediated tunable control of gene expression level with engineered single-guide RNA in Escherichia coli.

Precise control of gene expression is essential for flux redistribution in metabolic pathways. Although the CRISPR interference (CRISPRi) system can effectively repress gene expression at the transcriptional level, it has still been difficult to precisely control the level without loss of specificity or an increase in cell toxicity. In this study, we developed a tunable CRISPRi system that performs transcriptional regulation at various levels.

Synthetic biology tools for engineering .

is a promising organism for the industrial production of amino acids, fuels, and various value-added chemicals. From the whole genome sequence release, has been valuable in the field of industrial microbiology and biotechnology. Continuous discovery of genetic manipulations and regulation mechanisms has developed as a synthetic biology platform chassis.

dCas9-Mediated PCR-Free Detection of Oncogenic Mutation by Nonequilibrium Nanoelectrokinetic Selective Preconcentration.

Cutting-edge nanoelectrokinetic technology in this work provides a breakthrough for the present clinical demands of molecular diagnosis to detect a trace amount of oncogenic mutation of DNA in a short time without an erroneous PCR procedure. In this work, we combined the sequence-specific labeling scheme of CRISPR/dCas9 and ion concentration polarization (ICP) mechanism to separately preconcentrate target DNA molecules for rapid detection. Using the mobility shift caused by dCas9's specific binding to the mutant, the mutated DNA and normal DNA were distinguished in the microchip.

Effect of the Strategic Thinking, Problem Solving Skills, and Grit on the Disaster Triage Ability of Emergency Room Nurses.

In this descriptive study, we aimed to identify factors related to emergency room nurses' disaster triage ability. A total of 166 nurses who worked for emergency departments of general hospitals completed a structured questionnaire consisting of the Disaster Triage Ability Scale (DTAS), the Strategic Thinking Scale (STS), the Problem-Solving Inventory (PSI), and the Original Grit Scale (Grit-O). The data were analyzed using SPSS/WIN 25.

Synthetic cellular communication-based screening for strains with improved 3-hydroxypropionic acid secretion.

Although cellular secretion is important in industrial biotechnology, its assessment is difficult due to the lack of efficient analytical methods. This study describes a synthetic cellular communication-based microfluidic platform for screening strains with the improved secretion of 3-hydroxypropionic acid (3-HP), an industry-relevant platform chemical. 3-HP-secreting cells were compartmentalized in droplets, with receiving cells equipped with a genetic circuit that converts the 3-HP secretion level into an easily detectable signal.

Synthetic biosensor accelerates evolution by rewiring carbon metabolism toward a specific metabolite.

Proper carbon flux distribution between cell growth and production of a target compound is important for biochemical production because improper flux reallocation inhibits cell growth, thus adversely affecting production yield. Here, using a synthetic biosensor to couple production of a specific metabolite with cell growth, we spontaneously evolve cells under the selective condition toward the acquisition of genotypes that optimally reallocate cellular resources. Using 3-hydroxypropionic acid (3-HP) production from glycerol in Escherichia coli as a model system, we determine that mutations in the conserved regions of proteins involved in global transcriptional regulation alter the expression of several genes associated with central carbon metabolism.

A high coverage pseudotargeted lipidomics method based on three-phase liquid extraction and segment data-dependent acquisition using UHPLC-MS/MS with application to a study of depression rats.

Pseudotargeted analysis combines the advantages of untargeted and targeted lipidomics methods based on chromatography-mass spectrometry (MS). This study proposed a comprehensive pseudotargeted lipidomics method based on three-phase liquid extraction (3PLE) and segment data-dependent acquisition (SDDA). We used a 3PLE method to extract the lipids with extensive coverage from biological matrixes.

Engineering sp. SP1 for the production of carotenoids directly from brown macroalgae.

Macroalgae is regarded as a promising third-generation marine biomass that can be utilized as a sustainable feedstock for bio-industry due to the high sugar level and absence of lignin. Alginate, composed of 1,4-linked D-mannuronate (M) and L-guluronate (G), is one of the major carbohydrates in brown macroalgae. It is difficult to be assimilated by most industrial microorganisms.

Synthetic protein quality control to enhance full-length translation in bacteria.

Coupled transcription and translation processes in bacteria cause indiscriminate translation of intact and truncated messenger RNAs, inevitably generating nonfunctional polypeptides. Here, we devised a synthetic protein quality control (ProQC) system that enables translation only when both ends of mRNAs are present and followed by circularization based on sequence-specific RNA-RNA hybridization. We demonstrate that the ProQC system dramatically improved the fraction of full-length proteins among all synthesized polypeptides by selectively translating intact mRNA and reducing abortive translation.

Clinical Outcomes of Enteral Feeding Protocol Via Percutaneous Endoscopic Gastrostomy: A Single-Center, Retrospective Study.

Background: The development of the endoscopic technique has resulted in an increasing number of patients undergoing percutaneous endoscopic gastrostomy (PEG) insertion; however, the protocols for increasing the volume of feeding formula after PEG insertion have not been established. Therefore, we compared the clinical outcomes of patients receiving low- and high-volume increase in enteral feeding formula.

Methods: A total of 215 patients who underwent PEG insertion between January 2016 and March 2019 were included.

A novel formulation significantly increases the cytotoxicity of flaxseed orbitides (linusorbs) LOB3 and LOB2 towards human breast cancer MDA-MB-231 cells.

Flaxseed orbitides (linusorbs) are a family of N to C linked bioactive cyclic octa-, nona-, and decapeptides present in flaxseed oil. They are highly hydrophobic and thermally stable. Our previous studies showed that [1-9-NC]-linusorb B3 (LOB3) and [1-9-NC]-linusorb B2 (LOB2) exhibited cytotoxic effects towards human breast cancer HER2-subtype Sk-Br-3 cells at a concentration of ~400 μM.

Synthetic biology for evolutionary engineering: from perturbation of genotype to acquisition of desired phenotype.

With the increased attention on bio-based industry, demands for techniques that enable fast and effective strain improvement have been dramatically increased. Evolutionary engineering, which is less dependent on biological information, has been applied to strain improvement. Currently, synthetic biology has made great innovations in evolutionary engineering, particularly in the development of synthetic tools for phenotypic perturbation.

The investigation of protective effects of isosteviol sodium on cerebral ischemia by metabolomics approach using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry.

Cerebral ischemia remains a major cause of mortality and a long-term disability with limited therapies. Isosteviol sodium (STV-Na) was proved to exert significant protective effects on cerebral ischemia, but the protective mechanism was not understood. In this study, the protective effects of STV-Na on cerebral ischemia were investigated by the metabolomics approach based on ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry technique.

Synthetic auxotrophs for stable and tunable maintenance of plasmid copy number.

Although plasmid-based expression systems have advantages in multi-copy expression of genes, heterogeneity of plasmid copy number (PCN) in individual cells is inevitable even with the addition of antibiotics. Here, we developed a synthetic auxotrophic system for stable and tunable maintenance of the PCN in Escherichia coli without addition of antibiotics. This auxotroph expresses infA, one of the essential genes encoding a translation initiation factor, on a plasmid instead of on the chromosome.

Diffusiophoretic exclusion of colloidal particles for continuous water purification.

It has been observed that colloidal particles are anomalously repelled from the interface of nanoporous materials and water by up to hundreds of micrometers even if there is no additional external field present. Recently, the physical origin of this anomalous repulsion has turned out to be diffusiophoretic migration triggered by an ion exchange process through the interface. Since the repulsive force is induced by a salt gradient only, the phenomenon can be applied to a microscale water purification platform without the need for any external power sources.