Plant-derived Polymers Research Articles

A Green Approach to Copper-Containing Pesticides: Antimicrobial and Antifungal Activity of Brochantite Supported on Lignin for the Development of Biobased Plant Protection Products

After cellulose, lignin is the most abundant plant-derived polymer in nature. It provides mechanical support to plants, but it has also a defense role against pests and diseases, thanks to antioxid...

Planctomycetes in boreal and subarctic wetlands: diversity patterns and potential ecological functions.

Members of the phylum Planctomycetes are common inhabitants of boreal Sphagnum peat bogs and lichen-dominated tundra wetlands. These bacteria colonize both oxic and anoxic peat layers and reach the population size of 107 cells per gram of wet peat. The 16S rRNA gene sequences from planctomycetes comprise 5%-22% of total 16S rRNA gene reads retrieved from peat samples. Most abundant peat-inhabiting planctomycetes affiliate with the families Isosphaeraceae and Gemmataceae, and with as-yet-uncultured Phycisphaera-related group WD2101. The use of metatranscriptomics to assess the functional role of planctomycetes in peatlands suggested the presence of versatile hydrolytic capabilities in these bacteria. This evidence was further confirmed by the analysis of genome-encoded capabilities of isolates from wetlands. Large (up to 12 Mbp) genomes of planctomycetes encode wide repertoires of carbohydrate-active enzymes including many unclassified putative glycoside hydrolases, which suggests the presence of extremely high glycolytic potential in these bacteria. Experimental tests confirmed their ability to grow on xylan, pectin, starch, lichenan, cellulose, chitin and polysaccharides of microbial origin. These results provide an insight into the ecological roles of peat-inhabiting planctomycetes and suggest their participation in degradation of plant-derived polymers, exoskeletons of peat-inhabiting arthropods as well as exopolysaccharides produced by other bacteria.

Effect of Addition of PTFE on the Rheological and Mechanical Properties of CF Reinforced Plant-Derived Semi-Aromatic Polyamide (PA10T) Biomass Composites

For the purpose of this study is to develop the new engineering materials such as structural materials and tribomaterials (for sliding mechanical parts) based on plant-derived materials with sufficient balance among mechanical, processability, tribological properties, eco-friendliness, etc., we investigated the effect of addition of polytetrafluoroethylene (PTFE) on the rheological and mechanical properties of carbon fiber (CF) reinforced plant-derived semi-aromatic polyamide (PA10T) biomass composites. Especially, the relationship between various physical properties such as rheological and mechanical properties of these biomass composites and internal microstructure in the composites when added with PTFE or not were discussed in this study. PA10T is a kind of polyphthalamide (PPA, semi-aromatic polyamide) biomass polymer made from plant-derived decamethylenediamine and coal-derived terephthalic acid. In this study, PA10T was used as a matrix polymer. CF was used as the reinforcement fiber and its volume fraction was fixed on 20vol.%. PTFE was used as the solid lubricant and its weight fraction was fixed on 20wt.%. Various CF/PA10T/PTFE biomass composites were extruded using a twin screw extruder and injection molded. Rheological properties in the molten state were evaluated by oscillatory flow test using a parallel plate type rheometer. Mechanical properties such as tensile, bending, Izod impact and tribological properties were evaluated. Tribological properties were measured using a ring-on-plate type sliding wear tester at the room temperature under dry condition. The sliding surfaces of the test specimen, wear debris and counterface before/ after observation by a SEM with osmium (Os) sputter coating. To understand the internal microstructure in these biomass composites, the surface of the samples fractured cryogenically in liquid nitrogen was observed using SEM and the fiber length and its distribution were measured for the samples after injection molding.It was found that rheological properties such as storage modulus and complex viscosity of CF/PA10T biomass composites in molten state changed when added with PTFE. Mechanical properties such as strength and modulus of CF/PA10T/PTFE biomass composites are almost the same as those of CF/PTFE biomass composites, although tribological properties such as frictional coefficient, specific wear rate and limiting pv value improved when filled with PTFE. In particular, the limiting pv value of CF/PA10T/PTFE biomass composites remarkably improved due to the results of the synergistic effect, which is both mechanical and tribological properties are improved when filled with both PTFE and CF. These may be attributed to the change in the internal microstructure of these biomass composites such as fiber length, fiber dispersion and fiber-fiber interactions. Therefore, these results may contribute to the development of new engineering materials based on plant-derived polymer composites with sufficient balance among eco-friendliness, processability, mechanical and tribological properties.

Preclinical studies of VS-505: a non-absorbable highly effective phosphate binder.

Phosphate imbalance is often present in chronic kidney disease (CKD), and it contributes to a higher cardiovascular mortality rate. A phosphate binder is typically part of a treatment strategy for controlling phosphate imbalance. However, safety concerns and low compliance are two well-recognized disadvantages of on-market phosphate binders. This report describes the preclinical studies of VS-505, a non-absorbable, calcium- and aluminum-free, plant-derived polymer currently being evaluated in haemodialysis patients in Australia. Normal Sprague Dawley (SD) rats or uraemic SD rats induced by 5/6 nephrectomy fed a high-phosphate diet were treated with VS-505 or sevelamer (0.05-10% in food) for 5 and 28days respectively. Urinary and serum phosphate levels were significantly elevated in untreated rats, and were decreased by VS-505 and sevelamer. VS-505 increased faecal phosphate levels in a dose-dependent manner. High-phosphate diet also caused an increase in serum FGF-23 and parathyroid hormone in nephrectomized (NX) rats, effects prevented by VS-505 or sevelamer. Significant aortic calcification was observed in NX rats treated with 5% sevelamer, whereas VS-505 at all doses tested did not show effects. VS-505 had no effects on small intestine histomorphology and intestinal sodium-dependent phosphate cotransporter gene expression. In vitro characterizations showed that VS-505 has a relatively high density and low expansion volume when exposed to simulated gastric fluid. VS-505 is a safe and effective phosphate binder and may offer the advantage of having a reduced pill burden and minimal GI side effects for CKD patients.

Influence of Alkali Treatment on Mechanical Properties of Poly Lactic Acid Bamboo Fiber Green Composites

In recent years, in order to reduce the environmental burden of composite materials, research has been conducted to develop composites made from plant-derived polymers and natural fibers, the so called green composites. In this study, green composites were made from polylactic acid (PLA), a bioplastic derived from corn starch, reinforced with bamboo fibers. The composites were manufactured by mixing short bamboo fibers and dispersion-type PLA resin. Subsequently, PLA/bamboo fiber sheets were molded by a hot pressing method. In order to improve the adhesion at the matrix/fiber interface and to obtain uniformly dispersed bamboo fibers in PLA matrix, the bamboo fibers were treated by alkali solution. It was found that the composites reinforced by alkali-treated bamboo fibers have higher strength than those based on untreated ones. Bamboo fibers were uniformly dispersed in PLA matrix with improved interfacial adhesion as lignin in bamboo fibers were removed by the alkali treatment. It was concluded that alkali treatment was an effective method for improvement of interfacial matrix/fiber adhesion in PLA/bamboo fiber-reinforced green composites.

Supercritical CO2 Generation of Nanometric Structure from Ocimum basilicum Mucilage Prepared for Pharmaceutical Applications

Plant-derived polymers are widely used in the pharmaceutical industry due to their emollient, lack of toxicity, and irritating nature and low cost. In this work, basil seed mucilage was dried using supercritical carbon dioxide phase inversion technique to form a nanometric structure. The obtained polymeric structures were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) method, and Fourier transform infrared spectroscopy (FTIR) and compared with the oven-derived sample group. It was demonstrated that the product morphology could be controlled by altering the composition of methanol which functioned as the co-solvent in the nonsolvent stream. The most homogeneous product (60-nm mean pore size diameter, 78 m(2)/g BET surface area with no agglomeration) was obtained with 2.5% methanol. The FTIR data showed that the presence of hydroxyl and carboxyl groups suggested the bioadhesive property of basil seed mucilage was good and many active pharmaceutical compounds might be loaded to the resultant nanometric structure to enhance drug release. Furthermore, the FTIR analyses indicated that the nature of the final product did not change during the supercritical drying procedure.

VS-501: A NOVEL, NON-ABSORBED, CALCIUM- AND ALUMINUM-FREE, HIGHLY EFFECTIVE PHOSPHATE BINDER DERIVED FROM NATURAL PLANT POLYMER.

Inadequate control of serum phosphate in chronic kidney disease can lead to pathologies of clinical importance. Effectiveness of on-market phosphate binders is limited by safety concerns and low compliance due to high pill size/burden and gastrointestinal (GI) discomfort. VS-501 is a nonabsorbed, calcium- and aluminum-free, chemically modified, plant-derived polymer. In vitro studies show that VS-501 has a high density and a low swell volume when exposed to simulated gastric fluid (vs. sevelamer). When male Sprague–Dawley (SD) rats on normal diet were treated with VS-501 or sevelamer, serum phosphate was not significantly altered, but urinary phosphate levels decreased by >90%. VS-501 had no effect on serum calcium (Ca) or urinary Ca, while 3% sevelamer significantly increased serum and urine Ca. In 5/6 nephrectomized (NX) uremic SD rats on high-phosphate diet, increasing dietary phosphate led to an increase in serum and urine phosphate, which was prevented in rats treated with VS-501 or sevelamer (0.2–5% in food). High-phosphate diet also increased serum fibroblast growth factor-23 and parathyroid hormone in 5/6 NX rats that was prevented by VS-501 or sevelamer. VS-501 or sevelamer increased fecal phosphate in a dose-dependent manner. More aortic calcification was observed in 5/6 NX rats treated with 5% sevelamer, while VS-501 and sevelamer did not show significant effects on cardiac parameters, fibrosis, intestine histology, and intestinal sodium-dependent phosphate cotransporter gene expression. These results suggest that VS-501 is effective in binding phosphate with no effects on calcium homeostasis, and may have improved pill burden and GI side effects.

Analysis of commercial proanthocyanidins. Part 2: An electrospray mass spectrometry investigation into the chemical composition of sulfited quebracho (Schinopsis lorentzii and Schinopsis balansae) heartwood extract

Proanthocyanidins (PACs) are natural plant-derived polymers used in leather tanning, wood adhesives, water purification, and mud additives for oil drilling. Quebracho (Schinopsis lorentzii and Schinopsis balansae) heartwood and mimosa (Acacia mearnsii) bark extracts are the major industrial sources of PACs. These commercial extracts are often sulfited via treatment with sodium hydrogen sulfite to reduce their viscosity and increase their solubility in water. An ESI-MS investigation into the molecular composition of sulfited (cold-water-soluble) quebracho heartwood extract indicates that sulfitation of the PACs occurs via SN2 attack of a sulfite ion at both C-2 and C-4 of the constituent flavan-3-ol monomer extender units. Attack at C-2 leads to the opening of the pyran ring. This releases an additional electron-donating phenolic hydroxy group on the A-ring and renders the extract more nucleophilic and suitable for the manufacturing of adhesives. Attack at C-4 leads to interflavanyl bond fission and decrease of the PAC oligomer chain length. The introduction of sulfonic acid moieties at C-2 or C-4 increases the polarity and water solubility of the hot water soluble (unsulfited) extract and transforms it into a cold-water-soluble extract.

Complete Genome Sequence of the Cellulolytic Thermophile Caldicellulosiruptor obsidiansis OB47 T

Caldicellulosiruptor obsidiansis OB47(T) (ATCC BAA-2073, JCM 16842) is an extremely thermophilic, anaerobic bacterium capable of hydrolyzing plant-derived polymers through the expression of multidomain/multifunctional hydrolases. The complete genome sequence reveals a diverse set of carbohydrate-active enzymes and provides further insight into lignocellulosic biomass hydrolysis at high temperatures.

Production of Eucommia-rubber from Eucommia ulmoides Oliv. (Hardy Rubber Tree)

Eucommia ulmoides Oliver is a deciduous tree distributed in China, and is the only species in its genus, and the only genus in its family. It grows in temperate zones, and produces long-chain trans-polyisoprene throughout the entire plant. This trans-polyisoprene (TPI) derived from Eucommia is called Eucommia rubber (EU-rubber), and is a hydrocarbon with a carbon molecular weight of a few hundred thousand. EU-rubber is a hard rubber with thermoplasticity, and has properties similar to plastic. In terms of practical use, these plant-derived polymers are attracting attention as an industrial raw material to substitute for petroleum, and demand is expected to grow in the future. Hydrocarbon is also a fuel which has energy with the same value as petroleum.

Patterns of substrate utilization in species of Capronia and allied black yeasts: ecological and taxonomic implications

Forty-one isolates representing 14 members of the ascomycete genus Capronia and 15 black yeasts belonging to the anamorph genera Exophiala, Cladosporium, Ramichloridium and Rhinocladiella were tested for their ability to degrade amylose, casamino acids, casein, cellulose, chitin, gelatin, lignin, lipid, pectin and urea. The results of these tests were compared to assays for the breakdown of the same compounds by eight ascomycetes, basidiomycetes and zygomycetes that served as reference strains. Species of Capronia and black yeasts were unable to degrade amylose, cellulose, chitin, lignin and pectin. The utilization of casein, casamino acids, lipid, gelatin and urea varied among the taxa tested. These results indicate that plant-derived polymers and chitin are inaccessible to the Herpotrichiellaceae in natural systems and support the hypothesis that the members of this family are saprobes of secondary or higher incidence (hypersaprobes). Clinical and nonclinical Herpotrichiellaceae could not be discriminated on the basis of their enzymatic capabilities. Of the 12 substrate utilization tests employed in this study, only those used to assess the hydrolysis of casamino acids, casein and lipid proved valuable for distinguishing members of the genera Capronia, Exophiala and Ramichloridium. A simple method for detecting chitinolytic activity in fungi using chitin azure is described.

Indications from analytical pyrolysis on the evolution of organic materials in the temperate environment

Within the carbon cycle, organic carbon circulates mostly between the atmosphere the biomass. Smaller amounts of organic carbon however separate out into more slowly cycled pools characterized by dark coloured polymers, the humic substances, whilst arrested bioconversion leads to the accumulation of organic deposits as peats or aquatic sediments. This discussion paper examines from the standpoint of their pyrolysis characteristics, examples from the main groups of organic matter taken from these pools, including peat, freshwater and marine sediments, soils with developed humus, eluviated materials and organic matter which has undergone diagenesis in the wider geochemical cycle. It represents an initial attempt to co-ordinate widely ranging data which may not be strictly representative in some of these areas. Nevertheless a changing pattern of pyrolysis products is revealed by pyrolysis-mass spectrometry-based factor diagrams. These strongly suggest different principal lines of organic matter evolution by demonstrating significant differences of composition between them. Suites of products characteristic of plant-derived polymers, viz. lignins and polysaccharides, decrease with bioconversion, whilst others, such as various hydrocarbons and nitrogen heterocycles, build up according to the line of development. Processes of humification, eluviation, gleying, accumulation and fossilization are characterized.