Proteomic and Targeted Lipidomic Analyses of Fluid and Rigid Rubber Particle Membrane Domains in Guayule.

Rubber (-1,4-polyisoprene) is produced in cytosolic unilamellar vesicles called rubber particles (RPs), and the protein complex responsible for this synthesis, the rubber transferase (RTase), is embedded in, or tethered to, the membranes of these RPs. Solubilized enzyme activity is very difficult to achieve because the polymerization of highly hydrophilic substrates into hydrophobic polymers requires a polar/non-polar interface and a hydrophobic compartment. Using guayule () as a model rubber-producing species, we optimized methods to isolate RP unilamellear membranes and then a subset of membrane microdomains (detergent-resistant membranes) likely to contain protein complexes such as RTase.

Nitrile glove composition and performance-Substandard properties and inaccurate packaging information.

The durability and mechanical properties of synthetic medical gloves, such as those made from nitrile, vary drastically depending on the manufacturer. This study reports the chemical composition of several brands of nitrile gloves via FTIR and solid-state NMR analysis and relates composition to glove durability (found via GAD), mechanical performance (found via Instron), and whether the gloves meet or fail ASTM International standards. Out of the four nitrile examination glove brands tested, American Nitrile Slate brand had superior durability results and was found to be made of acrylonitrile butadiene rubber, as expected.

Medical glove durability during exposure to different solvent agents: an ex-vivo experimental study.

Background: Medical professionals are constantly exposed to bodily fluids and sanitizing agents during routine medical procedures. Unbeknownst to many healthcare workers, however, the barrier integrity of medical gloves can be altered when exposed to these substances, potentially resulting in exposure to dangerous pathogens.

Methods: This experimental study was designed to test the hypothesis that the durability of both natural and synthetic solvent-exposed medical gloves will be lower than the durability of the gloves in air.

Carbon Monoxide Alleviates Salt-Induced Oxidative Damage in by Inducing the Expression of Proline Biosynthesis and Antioxidant Genes.

Crop growth and yield are affected by salinity, which causes oxidative damage to plant cells. Plants respond to salinity by maintaining cellular osmotic balance, regulating ion transport, and enhancing the expression of stress-responsive genes, thereby inducing tolerance. As a byproduct of heme oxygenase (HO)-mediated degradation of heme, carbon monoxide (CO) regulates plant responses to salinity.

Natural rubber - Increasing diversity of an irreplaceable renewable resource.

This paper discusses the importance of introducing domestic natural rubber production and presents the rediscovery of a rubber-producing species, or "mountain gum", originally discovered in 1929 on the Karatau mountains in Kazakhstan. This plant could potentially also be cultivated in the U.S.

Effect of drought stress on natural rubber biosynthesis and quality in Taraxacum kok-saghyz roots.

Taraxacum kok-saghyz (TKS) is a potential source of natural rubber (NR) that can be grown in temperate regions with limited water availability. However, the effect of drought stress on NR production and properties in TKS isn't well studied. This study examined how different levels of drought stress (30, 60 and 90%) influenced the NR content, molecular weight (Mw), glass transition temperature (Tg), gene expression, and biochemical parameters in TKS roots.

Durability Variation Among Medical Gloves Made from Existing and New Elastomers Poses a Risk to Public Health.

Despite being an essential line of defense in preventing the spread of diseases, medical glove durability is neither measured routinely nor has standard specifications. In this study, a new glove durability assessment device is used to objectively compare the durability of gloves made of a variety of elastomers from different manufacturers. Results are related to several mechanical tests, including stress relaxation, tensile and tear tests.

Characterization and potential valorization of industrial food processing wastes.

Valorization and utilization of industrial food processing waste as value added products, platform chemicals and biofuels, are needed to improve sustainability and reduce waste management costs. Various industrial food waste stream samples were characterized with respect to their physico-chemical characteristics and elemental composition. A subset of starchy food wastes and milk dust powder were evaluated in batch fermentation to acetone, a useful platform chemical.

Programmable chemical actuator control of soluble and membrane-bound enzymatic catalysis.

Enzyme catalyzed reactions can be started, stopped, and throttled by regulating ion concentration in solution. The flow of charge through solution is related to the flow of electrons through an electric circuit using electrochemistry. However, current electrochemical methods to vary ionic concentration are largely limited to the electrode surface, making it impractical to exploit ionic concentration as a control variable in traditional enzyme assays.

Sustainable Epoxidized Guayule Natural Rubber, Blends and Composites with Improved Oil Resistance and Greater Stiffness.

Production of petroleum-based synthetic rubbers (SRs) causes an enormous carbon footprint for the rubber industry. Carbon footprint would be reduced if natural rubber (NR) could take a larger market share and replace significant quantities of SR. However, some SRs have higher oil resistance than NRs, and, in applications where these properties are needed, chemically modified NR will be required.

Liquid Guayule Natural Rubber, a Sustainable Processing Aid, Enhances the Processability, Durability and Dynamic Mechanical Properties of Rubber Composites.

Petroleum-based oils are widely used as processing aids in rubber composites to improve processability but can adversely affect rubber composite performance and increase carbon footprint. In this research, liquid guayule natural rubber (LGNR), produced from guayule natural rubber, was used as a renewable processing aid to replace naphthenic oil (NO) in Hevea natural rubber, styrene-butadiene rubber (SBR) and guayule natural rubber (GNR) composites. The rheological properties, thermal stability, glass transition temperature, dynamic mechanical properties, aging, and ozone resistance of rubber composites with and without NO or LGNR were compared.

Guayule Natural Rubber Latex and BiO Films for X-ray Attenuating Medical Gloves.

Existing natural latex radiation-attenuating gloves (RAGs) contain a high loading of radiation attenuation filler that reduces their mechanical properties to below Food and Drug Administration (FDA) medical glove requirements. RAGs are commonly formulated using Hevea natural rubber latex and lead-based fillers. The former can cause life-threatening allergic responses and the latter are known for their toxicity.

Adapting the Accelerated Solvent Extraction Method for Resin and Rubber Determination in Guayule Using the BÜCHI Speed Extractor.

Guayule ( Gray) is a promising alternative source to for the production of natural rubber, which can reach levels of 8-9% under industrialized farming conditions. The most common method for determining rubber concentration is by accelerated solvent extraction (ASE), a technique developed by the Dionex Corporation and almost exclusively performed with the Dionex ASE-200 or 350 systems. Herein, it is sought to apply and adapt the most common methods used in the literature for the Dionex system to another extraction platform, the BÜCHI Speed Extractor E-914.

Narrowing the Gap for Bioplastic Use in Food Packaging: An Update.

Plastic production has outgrown most other man-made materials, with more than 90% being petroleum-based and nonbiodegradable. Packaging, primarily food packaging, consumes the most plastic and is the largest contributor to municipal solid waste. In addition, its dependence on crude oil feedstock makes the plastic industry unsustainable and renders plastic markets vulnerable to oil price volatility.

Inactivation of the Levansucrase Gene in Paenibacillus polymyxa DSM 365 Diminishes Exopolysaccharide Biosynthesis during 2,3-Butanediol Fermentation.

The formation of exopolysaccharides (EPSs) during 2,3-butanediol (2,3-BD) fermentation by increases medium viscosity, which in turn presents considerable technical and economic challenges to 2,3-BD downstream processing. To eliminate EPS production during 2,3-BD fermentation, we used homologous recombination to disable the EPS biosynthetic pathway in The gene which encodes levansucrase, the major enzyme responsible for EPS biosynthesis in , was successfully disrupted. The levansucrase null mutant produced 2.

Natural rubber biosynthesis in plants, the rubber transferase complex, and metabolic engineering progress and prospects.

Natural rubber (NR) is a nonfungible and valuable biopolymer, used to manufacture ~50 000 rubber products, including tires and medical gloves. Current production of NR is derived entirely from the para rubber tree (Hevea brasiliensis). The increasing demand for NR, coupled with limitations and vulnerability of H.

Synergistic Mechanisms Underlie the Peroxide and Coagent Improvement of Natural-Rubber-Toughened Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Mechanical Performance.

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a promising bio-based and biodegradable thermoplastic with restricted industrial applications due to its brittleness and poor processability. Natural rubber (NR) has been used as a toughening agent, but further physical improvements are desired. In this study, rubber toughening efficiency was significantly improved through the synergistic use of a trifunctional acrylic coagent and an organic peroxide during reactive extrusion of PHBV and NR.

Unusual subunits are directly involved in binding substrates for natural rubber biosynthesis in multiple plant species.

Rubber particles from rubber-producing plant species have many different species-specific proteins bound to their external monolayer biomembranes. To date, identification of those proteins directly involved in enzymatic catalysis of rubber polymerization has not been fully accomplished using solubilization, purification or reconstitution approaches. In an alternative approach, we use several tritiated photoaffinity-labeled benzophenone analogs of the allylic pyrophosphate substrates, required by rubber transferase (RT-ase) to initiate the synthesis of new rubber molecules, to identify the proteins involved in catalysis.

Analysis of the first Taraxacum kok-saghyz transcriptome reveals potential rubber yield related SNPs.

Taraxacum kok-saghyz (TK) is a potential alternative crop for natural rubber (NR) production, due to its high molecular weight rubber, short breeding cycle, and diverse environmental adaptation. However, improvements in rubber yield and agronomically relevant traits are still required before it can become a commercially-viable crop. An RNA-Seq based transcriptome was developed from a pool of roots from genotypes with high and low rubber yield.

Improved axenic hydroponic whole plant propagation for rapid production of roots as transformation target tissue.

Background: Plant roots are used as an efficient target tissue for plant transformation assays. In root propagable species transformed roots are able to regenerate into whole plants without the addition of exogenous hormones, thus avoiding somaclonal variation associated with many plant transformation protocols. Plants grown in soil or soilless solid medium have roots that tend to be extremely delicate and are difficult to sterilize in advance of plant transformation experiments.

Chloroplast genome resources and molecular markers differentiate rubber dandelion species from weedy relatives.

Background: Rubber dandelion (Taraxacum kok-saghyz, TK) is being developed as a domestic source of natural rubber to meet increasing global demand. However, the domestication of TK is complicated by its colocation with two weedy dandelion species, Taraxacum brevicorniculatum (TB) and the common dandelion (Taraxacum officinale, TO). TB is often present as a seed contaminant within TK accessions, while TO is a pandemic weed, which may have the potential to hybridize with TK.

Compartmentalized Metabolic Engineering for Artemisinin Biosynthesis and Effective Malaria Treatment by Oral Delivery of Plant Cells.

Artemisinin is highly effective against drug-resistant malarial parasites, which affects nearly half of the global population and kills >500 000 people each year. The primary cost of artemisinin is the very expensive process used to extract and purify the drug from Artemisia annua. Elimination of this apparently unnecessary step will make this potent antimalarial drug affordable to the global population living in endemic regions.

Acetone-butanol-ethanol fermentation of corn stover: current production methods, economic viability and commercial use.

Biobutanol is a next-generation liquid biofuel with properties akin to those of gasoline. There is a widespread effort to commercialize biobutanol production from agricultural residues, such as corn stover, which do not compete with human and animal foods. This pursuit is backed by extensive government mandates to expand alternative energy sources.

Evaluation of industrial dairy waste (milk dust powder) for acetone-butanol-ethanol production by solventogenic Clostridium species.

Readily available inexpensive substrate with high product yield is the key to restoring acetone-butanol-ethanol (ABE) fermentation to economic competitiveness. Lactose-replete cheese whey tends to favor the production of butanol over acetone. In the current study, we investigated the fermentability of milk dust powder with high lactose content, for ABE production by Clostridium acetobutylicum and Clostridium beijerinckii.

Natural rubber biosynthesis in plants: rubber transferase.

Rubber biosynthesis in plants is a fascinating biochemical system, which evolved at the dawn of the dicotyledoneae and is present in at least four of the dictolydonous superorders. Rubber biosynthesis is catalyzed by a membrane complex in a monolayer membrane envelope, requires two distinct substrates and a divalent cation cofactor, and produces a high-molecular-weight isoprenoid polymer. A solid understanding of this system underpins valuable papers in the literature.