Production of 1,2-propanediol from glycerol in Klebsiella pneumoniae GEM167 with flux enhancement of the oxidative pathway.

Background: To support the sustainability of biodiesel production, by-products, such as crude glycerol, should be converted into high-value chemical products. 1,2-propanediol (1,2-PDO) has been widely used as a building block in the chemical and pharmaceutical industries. Recently, the microbial bioconversion of lactic acid into 1,2-PDO is attracting attention to overcome limitations of previous biosynthetic pathways for production of 1,2-PDO.

Whole-Cell P450 Biocatalysis Using Engineered Escherichia coli with Fine-Tuned Heme Biosynthesis.

By exploiting versatile P450 enzymes, whole-cell biocatalysis can be performed to synthesize valuable compounds in Escherichia coli. However, the insufficient supply of heme limits the whole-cell P450 biocatalytic activity. Here a strategy for improving intracellular heme biosynthesis to enhance the catalytic efficiencies of P450s is reported.

Light-Driven Ammonia Production by Cultured in Medium Containing Colloidal Quantum Dots.

There is an evergrowing demand for environment-friendly processes to synthesize ammonia (NH) from atmospheric nitrogen (N). Although diazotrophic N fixation represents an undeniably "green" process of NH synthesis, the slow reaction rate makes it less suitable for industrially meaningful large-scale production. Here, we report the photoinduced N fixation using a hybrid system composed of colloidal quantum dots (QDs) and aerobic N-fixing bacteria, .

Biosynthesis and applications of iron oxide nanocomposites synthesized by recombinant Escherichia coli.

Recombinant Escherichia coli (E. coli) strain that produces phytochelatin (PC) and/or metallothionein (MT) can synthesize various metal nanoparticles (NPs) by reducing metal ions. Here we report in vivo biosynthesis of iron oxide nanocomposites (NCs) using recombinant E.

Quantumness and thermodynamic uncertainty relation of the finite-time Otto cycle.

To reveal the role of the quantumness in the Otto cycle and to discuss the validity of the thermodynamic uncertainty relation (TUR) in the cycle, we study the quantum Otto cycle and its classical counterpart. In particular, we calculate exactly the mean values and relative error of thermodynamic quantities. In the quasistatic limit, quantumness reduces the productivity and precision of the Otto cycle compared to that in the absence of quantumness, whereas in the finite-time mode, it can increase the cycle's productivity and precision.

Biosynthesis of inorganic nanomaterials using microbial cells and bacteriophages.

Inorganic nanomaterials are widely used in chemical, electronics, photonics, energy and medical industries. Preparing a nanomaterial (NM) typically requires physical and/or chemical methods that involve harsh and environmentally hazardous conditions. Recently, wild-type and genetically engineered microorganisms have been harnessed for the biosynthesis of inorganic NMs under mild and environmentally friendly conditions.

Finite-time quantum Otto engine: Surpassing the quasistatic efficiency due to friction.

In finite-time quantum heat engines, some work is consumed to drive a working fluid accompanying coherence, which is called "friction." To understand the role of friction in quantum thermodynamics, we present a couple of finite-time quantum Otto cycles with two different baths: Agarwal versus Lindbladian. We solve them exactly and compare the performance of the Agarwal engine with that of the Lindbladian engine.

Biocatalytic synthesis of polylactate and its copolymers by engineered microorganisms.

Poly(lactate), also called poly(lactic acid) or poly(lactide) [PLA], has been one of the most attractive bio-based polymers since it possesses desirable material properties for its use in general performance plastics in addition to biodegradability and biocompatibility. PLA has been produced by biological and chemical hybrid process comprising microbial fermentation for lactate (LA) production followed by purification and chemical polymerization process of LA. Recently, the direct one-step fermentative processes for production of PLA and several LA-containing polyesters have been developed by employing metabolically engineered microorganisms.

Role of hubs in the synergistic spread of behavior.

The spread of behavior in a society has two major features: the synergy of multiple spreaders and the dominance of hubs. While strong synergy is known to induce mixed-order transitions (MOTs) at percolation, the effects of hubs on the phenomena are yet to be clarified. By analytically solving the generalized epidemic process on random scale-free networks with the power-law degree distribution p_{k}∼k^{-α}, we clarify how the dominance of hubs in social networks affects the conditions for MOTs.

Metabolic engineering of microorganisms for production of aromatic compounds.

Metabolic engineering has been enabling development of high performance microbial strains for the efficient production of natural and non-natural compounds from renewable non-food biomass. Even though microbial production of various chemicals has successfully been conducted and commercialized, there are still numerous chemicals and materials that await their efficient bio-based production. Aromatic chemicals, which are typically derived from benzene, toluene and xylene in petroleum industry, have been used in large amounts in various industries.

In Vivo Synthesis of Nanocomposites Using the Recombinant Escherichia coli.

Biogenic gold nanorod (AuNR)-Ag core-shell nanocomposites (NCs) are synthesized by using recombinant Escherichia coli to demonstrate in vivo synthesis of biogenic NCs for the first time. The chemically synthesized AuNRs are internalized into the E. coli, and Ag ions are reduced and grown on the surface of the AuNRs with the assistance of metal-binding proteins, producing biogenic core-shell AuNR-Ag NCs.

Structural Insights into Polyhydroxyalkanoates Biosynthesis.

Polyhydroxyalkanoates (PHAs) are diverse biopolyesters produced by numerous microorganisms and have attracted much attention as a substitute for petroleum-based polymers. Despite several decades of study, the detailed molecular mechanisms of PHA biosynthesis have remained unknown due to the lack of structural information on the key PHA biosynthetic enzyme PHA synthase. The recently determined crystal structure of PHA synthase, together with the structures of acetyl-coenzyme A (CoA) acetyltransferase and reductase, have changed this situation.

Markerless gene knockout and integration to express heterologous biosynthetic gene clusters in Pseudomonas putida.

Pseudomonas putida has gained much interest among metabolic engineers as a workhorse for producing valuable natural products. While a few gene knockout tools for P. putida have been reported, integration of heterologous genes into the chromosome of P.

Recent Trends in Nanomaterials-Based Colorimetric Detection of Pathogenic Bacteria and Viruses.

Rapid, sensitive, selective, convenient, and cost-effective pathogen diagnosis is important to prevent further spread of pandemic diseases, minimize social and economic losses, and to facilitate right clinical therapy. Over the past few years, various sensor-based diagnostic systems outperforming conventional pathogenic diagnostic assays have been developed. Among them, colorimetric biosensors detecting target molecules by the naked eye have attracted much attention due to their simplicity, practicality, and cost-effectiveness.

Biosynthesis of 2-Hydroxyacid-Containing Polyhydroxyalkanoates by Employing butyryl-CoA Transferases in Metabolically Engineered Escherichia coli.

The authors previously reported the production of polyhydroxyalkanoates (PHAs) containing 2-hydroxyacid monomers by expressing evolved Pseudomonas sp. 6-19 PHA synthase and Clostridium propionicum propionyl-CoA transferase in engineered microorganisms. Here, the authors examined four butyryl-CoA transferases from Roseburia sp.

CRISPR/Cas9-coupled recombineering for metabolic engineering of Corynebacterium glutamicum.

Genome engineering of Corynebacterium glutamicum, an important industrial microorganism for amino acids production, currently relies on random mutagenesis and inefficient double crossover events. Here we report a rapid genome engineering strategy to scarlessly knock out one or more genes in C. glutamicum in sequential and iterative manner.

Effects of a local defect on one-dimensional nonlinear surface growth.

The slow-bond problem is a long-standing question about the minimal strength ε_{c} of a local defect with global effects on the Kardar-Parisi-Zhang (KPZ) universality class. A consensus on the issue has been delayed due to the discrepancy between various analytical predictions claiming ε_{c}=0 and numerical observations claiming ε_{c}>0. We revisit the problem via finite-size scaling analyses of the slow-bond effects, which are tested for different boundary conditions through extensive Monte Carlo simulations.

Genomic and transcriptomic landscape of Escherichia coli BL21(DE3).

Escherichia coli BL21(DE3) has long served as a model organism for scientific research, as well as a workhorse for biotechnology. Here we present the most current genome annotation of E. coli BL21(DE3) based on the transcriptome structure of the strain that was determined for the first time.

Crystal structure of Ralstonia eutropha polyhydroxyalkanoate synthase C-terminal domain and reaction mechanisms.

Polyhydroxyalkanoates (PHAs) are natural polyesters synthesized by numerous microorganisms as energy and reducing power storage materials, and have attracted much attention as substitutes for petroleum-based plastics. Here, we report the first crystal structure of Ralstonia eutropha PHA synthase at 1.8 Å resolution and structure-based mechanisms for PHA polymerization.

Structure and function of the N-terminal domain of Ralstonia eutropha polyhydroxyalkanoate synthase, and the proposed structure and mechanisms of the whole enzyme.

Polyhydroxyalkanoates (PHAs) are natural polyesters synthesized by numerous microorganisms as energy and reducing power storage materials, and have attracted much attention as substitutes for petroleum-based plastics. In an accompanying paper, the authors reported the crystal structure of the C-terminal domain of Ralstonia eutropha PHA synthase (PhaC1). Here, the authors report the 3D reconstructed model of full-length of R.

Biosynthesis of poly(2-hydroxyisovalerate-co-lactate) by metabolically engineered Escherichia coli.

Polyhydroxyalkanoates (PHAs) containing 2-hydroxyacids such as lactate (LA) and 2-hydroxybutyrate (2HB) have recently been produced by metabolically engineered microorganisms. Here, we further expanded 2-hydroxyacid monomer spectrum of PHAs by engineering Escherichia coli to produce PHAs containing 2-hydroxyisovalerate (2HIV). To generate 2HIV in vivo, feedback resistant ilvBNmut genes encoding acetohydroxyacid synthase and ilvCD genes encoding ketol-acid reductoisomerase and dihydroxyacid dehydratase, respectively, and panE gene encoding d-2-hydroxyacid dehydrogenase are overexpressed.