Chemically Recyclable and Tunable Polyolefin-Like Multiblock Copolymer Adhesives.

Adhesives are important in creating multilayer products, such as in packaging and construction. Most current hot-melt adhesives such as poly(ethylene-co-vinyl acetate) (EVA) and polyurethanes lack chemical recyclability and do not easily de-bond, complicating recycling. Here, we achieved tunable adhesive properties of chemically recyclable polyolefin-like multiblock copolymers through regulating the incorporation of crystalline hard blocks, amorphous soft blocks, and ester content highlighted by adhesive strengths up to 6.

Quantitative decoding of coupled carbon and energy metabolism in Pseudomonas putida for lignin carbon utilization.

Soil Pseudomonas species, which thrive on lignin derivatives, are widely explored for biotechnology applications in lignin valorization. However, how the native metabolism coordinates phenolic carbon processing with required cofactor generation remains poorly understood. Here, we achieve quantitative understanding of this metabolic balance through a detailed multi-omics investigation of Pseudomonas putida KT2440 grown on four common phenolic acid substrates: ferulate, p-coumarate, vanillate, and 4-hydroxybenzoate.

Methods for Carbon Mass Closure in Polyolefin Hydrocracking.

Heterogeneous catalytic hydrocracking of polyolefins is a promising approach for the processing of postconsumer plastics, but product quantification methods remain inconsistent across the literature. In systems that generate a large fraction of vapor-phase products, typical product capture methods can result in large carbon balance deficits, exceeding 50%, compromising reported yields and selectivities. Here, we identify the major sources of product loss and develop enhanced capture methods to improve the quantification accuracy.

Lignin-Derived Methoxyterephthalates for Performance-Advantaged Polymers and Plasticizers.

Lignin-derived aromatic carboxylic acids can be produced from oxidative catalytic processes and are promising building blocks for performance-advantaged bioproducts that leverage their inherent heteroatom functionalities. Here, we synthesize 2-methoxyterephthalate and 2,6-dimethoxyterephthalate derivatives by electrochemical carboxylation of guaiacyl- and syringyl-derived lignin monomers obtained from the oxidative deconstruction of lignin. These methoxylated terephthalates are evaluated as co-monomers in poly(ethylene terephthalate) (PET) and as plasticizers that could replace petrochemically-derived isophthalate and phthalate, respectively.

Rewiring Aromatic Compound Consumption: Chromosomal Amplification and Evolution of a Foreign Pathway in ADP1.

Rational engineering strategies that seek to harness the remarkable diversity of microbial metabolism can be limited by incomplete biological knowledge. As described here, a novel approach to address this challenge involved replacing a native pathway for degrading lignin-derived aromatic compounds via cleavage of protocatechuate in ADP1 with a foreign -cleavage pathway that uses different enzymes, metabolites, and redox carriers. This alteration may improve lignin valorization and coordinate catabolism with bioproduction strategies.

Engineering PHL7 for improved poly(ethylene terephthalate) depolymerization via rational design and directed evolution.

Enzymatic depolymerization of poly(ethylene terephthalate) (PET) has emerged as a promising approach for polyester recycling, and, to date, many natural and engineered PET hydrolase enzymes have been reported. For industrial use, PET hydrolases must achieve high depolymerization extent and exhibit excellent thermostability. Here, we engineered a natural PET hydrolase, Polyester Hydrolase Leipzig #7 (PHL7), through rational design and directed evolution using a high-throughput screening platform.

Lignin Extraction and Condensation as a Function of Temperature, Residence Time, and Solvent System in Flow-through Reactors.

Solvolytic extraction of lignin from biomass is a critical step in lignin-first biorefining, including the reductive catalytic fractionation (RCF) process. Key to optimal RCF processing is the ability to rapidly extract lignin from biomass at high delignification extents and transfer the lignin molecules to a catalyst surface in a time frame that minimizes lignin condensation reactions. Here, we use a flow-through reactor to study the effects of temperature (175-250 °C), residence time (9 to 36 min), and solvent composition (methanol and methanol-water) on lignin extraction and condensation.

Implementation and evaluation of multi-dual mode counter-current chromatography in the CUP Modeler software.

Counter-current chromatography (CCC) is a separation technique that utilizes immiscible solvent pairs as stationary and mobile phases, which imparts numerous benefits compared to solid-liquid chromatography including the ability to treat either the more-dense or less-dense solvent layer as the mobile phase. Multi-dual mode (MDM) is a CCC elution mode capable of improving the separation of closely eluting compounds by alternating upper- and lower-layer solvent flows in opposing directions within the same separation. While some effort has been made to model MDM, implementation of these models in experimental design has yet to be widely adopted.

Secure biosystems design in establishes effective biocontainment strategies and mechanisms of escape.

The widespread application of recombinant DNA and synthetic biology approaches for microbial metabolic engineering pursuits has motivated the development of biocontainment strategies, targeting safe and secure deployment of genetically modified microorganisms (GMMs). However, the design rules and mechanistic drivers governing biocontainment efficacy, as well as impacts of biocontainment upon microbial fitness, remain to be comprehensively evaluated, hindering predictive design and application of these strategies. We have developed a platform for high-resolution analysis of a transactivated kill switch in laboratory and industrial strains of to assess modes of biocontainment escape and establish design rules for development of kill switch systems in diverse microbes.

Open Specy 1.0: Automated (Hyper)spectroscopy for Microplastics.

Microplastic spectral analysis is one of the most time-consuming processes in studying microplastic pollution, often requiring days per sample. Researchers are transitioning to automated batch and hyperspectral image analysis techniques to enhance efficiency. Open Specy, initially aimed at manual single-spectrum analysis, has now integrated automated methods.

Storage-Induced Collapse of Lignin Macromolecular Structure and Its Impacts on the Biorefinery.

Lignin plays a vital role in the economics of biorefineries, serving as a source of process energy and a feedstock for sustainable fuels and chemical production. While understanding lignin's chemical composition is crucial, emerging evidence suggests that a more comprehensive understanding of its macromolecular structure is critical to explaining its complex behavior in the biorefinery. This study investigated the collapse of the lignin network in corn stover feedstock after harvest and storage as a result of the microbial digestion of hemicellulose.

Biotechnological solutions for critical mineral recovery from unconventional feedstocks.

Secure and sustainable metal recovery from unconventional feedstocks is needed to meet the mineral demands of energy, defense, and electronic technologies. Here, we highlight the potential to leverage nature's ability to extract and differentiate metal ions in biotechnologies that could become the next generation of mining and refining. We describe bulk and trace processes and then discuss the advances and opportunities of two key bioprocesses: microbially mediated solubilization of metal ions from solid matrices (termed 'bioleaching') and bio-based separation of solubilized ions via selective adsorption to proteins.

Cross-kingdom comparative genomics reveal the metabolic potential of fungi for lignin turnover in deadwood.

Deadwood is a major carbon source in forests, and yet the fate of this carbon remains a gap in our understanding of global carbon cycling. Lignin, the most recalcitrant biopolymer in wood, is mainly decayed through extracellular enzymatic and chemical processes initiated by white-rot fungi. However, the intracellular conversion of lignin decay products has been overlooked in the fungal kingdom.

Integrated thermal and biological conversion of microalgal proteins to lipids.

Microalgal composition varies with cultivation strategy, and low-cost approaches often produce high-protein biomass. This presents challenges for biorefineries designed around static, lipid-rich feedstocks. In particular, hydrolysates from high-protein algae are nitrogen-rich and sugar-poor, limiting microbial conversion and reducing product yields.

Engineered Membrane Vesicle Production via or Deletion Has Distinct Phenotypic Effects in .

Membrane vesicle (MV) production is a natural phenomenon in Gram-negative bacteria and represents an emerging synthetic biology tool for the secretion of biomolecules or bioproducts. Manipulation of membrane components has proven successful in enhancing MV production. However, the impact of membrane disruptions on strain fitness and protein composition warrants further investigation for the use of MVs in industrial bioprocesses.

Development and flight-testing of modular autonomous cultivation systems for biological plastics upcycling aboard the ISS.

Cultivation of microorganisms in space has enormous potential to enable in-situ resource utilization (ISRU) Here, we develop an autonomous payload with fully programmable serial passaging and sample preservation, termed the Modular Open Biological Platform (MOBP), and flight-test the MOBP aboard the International Space Station (ISS) by conducting enzymatic and microbial plastics upcycling experiments. The MOBP is a compact, modular bioreactor system that allows for sustained microbial growth via automated media transfers, such as those for sample collection and storage for terrestrial analyses, and precise data monitoring from integrated sensors. The MOBP was flight-tested with two experiments designed to evaluate biological upcycling of the plastic poly(ethylene terephthalate) (PET).

Insights into genetic determinants of volatile fatty acid catabolism in H16.

Unlabelled: The soil bacterium H16 is a promising host for upgrading waste-derived volatile fatty acids (VFAs) into renewable biochemicals. While bacterial VFA metabolic pathways are well understood, the genome encodes multiple enzymes for each catabolic step, and the degree of substrate specificity among these homologs is currently unknown. To gain insight into the catabolism of VFA substrates in , we performed transcriptomics on cells grown with acetate, propionate, butyrate, valerate, or hexanoate as the sole source of carbon and energy.

Acetolysis for epoxy-amine carbon fibre-reinforced polymer recycling.

Carbon fibre-reinforced polymers (CFRPs) are used in many applications in the global energy transition, including for lightweighting aircraft and vehicles and in wind turbine blades, shipping containers and gas storage vessels. Given the high cost and energy-intensive manufacture of CFRPs, recycling strategies are needed that recover intact carbon fibres and the epoxy-amine resin components. Here we show that acetic acid efficiently depolymerizes both aliphatic and aromatic epoxy-amine thermosets used in CFRPs to recoverable monomers, yielding pristine carbon fibres.

Production of Vanillin From Ferulic Acid by Pseudomonas putida KT2440 Using Metabolic Engineering and In Situ Product Recovery.

Vanillin is the most in-demand flavouring compound in the world and because vanillin extracted from vanilla pods cannot meet the global demand, most vanillin on the market today is chemically synthesised. Increasing demands by consumers for natural ingredients have inspired efforts to develop vanillin derived from microbial sources. These efforts have been challenged by low titers, likely caused by the toxicity of vanillin to most microbial biocatalysts.

Carboxylic Acid Concentration in Downstream Bioprocessing Using High-Pressure Reverse Osmosis.

During the production of many bio-based chemicals from fermentation and enzymatic processes, product separations frequently represent the most expensive and energy-intensive unit operations in an integrated process, often due to the low concentrations of target bioproducts. In this study, we integrated high-pressure reverse osmosis (HPRO) to concentrate an exemplary fermentation product, butyric acid, prior to downstream extraction. Through both modeling and experimental measurements, we identified the major factors limiting the maximum achievable concentration factor (CF) of 4.

Solid-state NMR at natural isotopic abundance for bioenergy applications.

Lignocellulosic biomass offers a vast and renewable resource for biofuel production and carbon management solutions. The effective conversion of lignocellulosic biomass into economically competitive biofuels and bioproducts demands a comprehensive understanding of its complex structure and composition, often requiring a range of analytical tools to achieve meaningful insights. However, for the analysis of rigid solids, many traditional methods necessitate dissolution or chemical/physical modification of the sample, which limit our ability to capture an intact view of its structural components.

Optimizing Cupriavidus necator H16 as a host for aerobic C1 conversion.

Biological systems capable of converting CO or CO-derived, single-carbon (C1) compounds can be used to reduce or reverse carbon emissions while establishing a circular bioeconomy to provide sustainable sources of the fuels, foods, and materials humanity relies on. A robust bioeconomy will rely upon a variety of microorganisms capable of assimilating C1 compounds and converting them to valuable products at industrial scale. While anaerobic microbes are ideal hosts for production of short-chain acids and alcohols, microbes capable of aerobic respiration are well suited for biosynthesis of higher molecular weight products.

Quantitative Analysis of Coupled Carbon and Energy Metabolism for Lignin Carbon Utilization in .

Soil species, which can thrive on lignin-derived phenolic compounds, are widely explored for biotechnology applications. Yet, there is limited understanding of how the native metabolism coordinates phenolic carbon processing with cofactor generation. Here, we achieve quantitative understanding of this metabolic balance through a multi-omics investigation of KT2440 grown on four common phenolic substrates: ferulate, coumarate, vanillate, and 4-hydroxybenzoate.

Tunable and Degradable Dynamic Thermosets from Compatibilized Polyhydroxyalkanoate Blends.

Polyhydroxyalkanoates (PHAs) are versatile, biobased polyesters that are often targeted for use as degradable thermoplastic replacements for polyolefins. Given the substantial chemical diversity of PHA, their potential as cross-linked polymers could also enable similar platforms for reversible, degradable thermosets. In this work, we genetically engineered KT2440 to synthesize poly(3-hydroxybutyrate--3-hydroxyundecenoate) (PHBU), which contains both 3-hydroxybutyrate and unsaturated 3-hydroxyundecenoate components.

Synthetic Genetic Elements Enable Rapid Characterization of Inorganic Carbon Uptake Systems in H16.

H16 is a facultative chemolithotroph capable of using CO as a carbon source, making it a promising organism for carbon-negative biomanufacturing of petroleum-based product alternatives. In contrast to model microbes, genetic engineering technologies are limited in , constraining its utility in basic and applied research. Here, we developed a genome engineering technology to efficiently mobilize, integrate, and express synthetic genetic elements (SGEs) in .