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Biological synthesis of high added-value compounds like adipic acid (AA), levulinic acid (LA), or polyhydroxybutyrate (PHB) using pure culture has been separately reported. However, pure culture requires sterile conditions and the use of specific carbon sources resulting in high operating costs. Different alternatives based on the use of mixed microbial cultures (MMC) have been explored to resolve this problem. MMC have been widely reported for the production of PHB, but scarcely reported for LA production and never for AA synthesis. This work presents a novel strategy for the co-production of AA LA, and PHB using MMC. The strategy consists in selecting an MMC producer of AA, LA and PHB from an inoculum obtained from a wastewater treatment plant, which is then subjected to the feast and famine culture strategy in a sequential batch reactor, coupled with a batch reactor step to enhance the accumulation of AA and LA. The results showed that the MMC could produce a 16 ± 2, 23 ± 1 and 5 ± %1 (g compound/g volatile solids) of AA, LA and PHB, respectively, using a non-fermented residual biomass rich in pentose, namely synthetic hemicellulose hydrolysate (SHH) as the carbon source. These results contribute to generating future research to better understand and optimise the biosynthesis of these compounds by MMC. [ABSTRACT FROM AUTHOR]

Industrial crops are becoming increasingly relevant as raw materials for different goods and services. Although there are many oilseed crops with industrial purposes, data about their production in Chile are scarce because the definition used by the Office of Agricultural Studies and Policies places agro‐industrial and industrial crops in the same category. Here, we review the available information about 12 industrial oleaginous crops at different levels of development (four native, two adventive and six introduced crops). Most of these crops have been evaluated for or are related to biodiesel production, despite the lack of commercial biodiesel production in Chile. Jojoba was the first industrial oilseed produced commercially in Chile; however, every year its production area decreases, and currently it does not exceed 100 ha. Sunflower and rapeseed, which are the first generation of raw materials for biodiesel production, have been poorly studied in Chile despite the large number of studies available on them worldwide. Camelina and castor bean have recently been studied; the former is produced in the south, while the latter is produced on the coastline in northern Chile. Further research is needed to improve the production and adaptation of these oilseed crops to climatic conditions in Chile; moreover, a new market must be opened to produce and commercialize their oils. Oilseed species native to Chile have not been extensively studied, and they represent an interesting option suitable for production under Chilean climatic conditions; this is particularly true for guindilla and chañar, because both can grow under different abiotic stresses. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

BACKGROUND: Polyhydroxyalkanoates (PHAs) are a class of biodegradable biopolymers produced and accumulated by microorganisms. PHAs are recovered from microbial biomass through the stages of pretreatment, extraction and purification. An alternative recovery method is microwave‐assisted extraction (MAE), which involves the supply of energy through an electromagnetic field, generating high temperatures in reduced times. A study to evaluate the recovery of PHAs from mixed microbial cultures was conducted using MAE. This method was evaluated through a four‐factorial experimental design, with the efficiency as the evaluated response. PHAs were also recovered using conventional heat extraction as control. RESULTS: It was found that the highest efficiency achieved using MAE was 68 ± 1.2% (w/w), which was close to the 66 ± 5.3% (w/w) obtained using conventional heat extraction. The following combination of factors corresponded to the optimum conditions of experimental design: extraction time of 1 min, temperature of 130 °C, chloroform‐to‐methanol ratio of 1:1 and solvent‐to‐biomass ratio of 20 volumes. The efficiency increased substantially when the solvent‐to‐biomass ratio and chloroform‐to‐methanol ratio increased, although the temperature was the least significant factor. Functional groups, decomposition temperatures (263–309 °C) and melting point (158 °C) of MAE‐recovered PHAs were similar to those measured for commercial poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)]. CONCLUSIONS: MAE is a never‐before‐reported useful method for recovering PHAs from mixed microbial cultures, which provides for a high extraction efficiency and quality of the recovered biopolymers. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Frost is an important abiotic stress for plants and crops because of the economic losses that are incurred. Plants have two mechanisms for freezing protection: freezing avoidance and freezing tolerance. The former prevents extrinsic and/or intrinsic ice nucleation, while the latter provides plants with tools to survive apoplastic ice formation, by several coordinated physiological and biochemical features such as the increase in cryoprotectants (metabolites and proteins) which in general maintain cell membrane and cells macromolecules stability, cause a freezing point depression or decrease the cell osmolarity preventing the severe cell dehydration caused by apoplastic freezing. Many products against freezing have been developed, and there are at least 20 products on the international market. Ten products mainly avoid ice formation by forming semi‐permeable or permeable membranes that inhibit extrinsic ice nucleation over leaves, three products work for favouring tolerating ice formation in plants, and two use both mechanisms of action. Some kind of lipids, such as phospholipids and α‐tocopherol, effectively maintain the stability and integrity of cell membranes, while some osmolytes (mainly polyols) decrease the freezing point of water, both inside and outside the cell, but also can interact with the polar moieties of phospholipids stabilizing membranes. Despite this, more information on products for crop protection against freezing is required in order to determine their effectiveness. New formulations that protect crops against freezing must include ingredients that employ both mechanisms. The use of lipids is likely to continue while new alternatives that reduce ice formation are evaluated, among which antifreeze and cryoprotective proteins may offer attractive alternatives. [ABSTRACT FROM AUTHOR]

The effects of the pyrolysis conditions in terms of temperature (400 to 600 °C), residence time (0.5 to 3.5 h), nitrogen flux (0 to 1 L/min), and temperature increase rate (1.5 to 3 °C/min) on the physicochemical properties of biochar were studied. The physicochemical properties evaluated in the biochar were specific surface area, pore volume, average pore size, total carbon content, pH, total acidity, elemental composition, and polycyclic aromatic hydrocarbons (PAHs) content. A higher specific surface area of 108.28 m²/g and a mean pore size diameter of about 2.24 nm were found when the pyrolysis was conducted at 600 °C. In general, the pH and total acidity increased with the increased pyrolysis temperature. The total PAH concentration in all of the combinations studied varied from 0.16 to 8.73 μg/kg, and only phenanthrene, pyrene, and chrysene were detected. The increased temperature seemed to decrease the PAH concentration in the biochar. Nevertheless, there was no correlation found between the PAH content and the combined evaluated parameters. [ABSTRACT FROM AUTHOR]

The Freundlich model and the Constant Capacitance Model (CCM) were used to describe silicon (Si) and phosphorus (P) sorption, both individually and for binary P–Si systems, on two Andisols with different chemical properties: Freire soil (FS) and Piedras Negras soil (PNS). Silicon sorption kinetics were examined through the Elovich equation, revealing that the initial sorption rate was 16 times greater in PNS. The Freundlich equation provides a good fit to the sorption data for both Andisols. When compared with FS, larger Si sorption capacity and lower Si affinity for the surface sites were observed in PNS; nevertheless, Si sorption decreased in both soils as P sorption increased. Slight reductions in P sorption capacity due to the presence of Si were found, whereas there was no apparent effect on P bonding intensity. The CCM was able to describe Si adsorption, and potentiometric titrations support that Si seems to be specifically sorbed mainly onto sites of negative charge. Comparable log K Si int values were obtained for both soils, indicating that Si was bound on similar sites. Phosphorus sorption was well described by the CCM, and log K P int denoted strong interactions of P with the surface sites. For binary systems, log K P int did not vary with increasing Si concentration; comparatively, log K Si int scarcely decreased with increasing P concentration in PNS, but a 28% reduction was found in FS at the highest initial P concentration. [ABSTRACT FROM AUTHOR]

BACKGROUND Biodiesel production is not economically competitive with petroleum diesel particularly when using virgin and refined vegetable oils. Rich-in-oil miscella obtained from the extraction of soybean oil with ethanol may be a promising feedstock for taking off the refining process, simultaneously introducing an environmental friendly step by replacing hexane by ethanol as a renewable solvent in the oil extraction process. The aim of this study was to investigate the production of biodiesel from the oil-ethanol miscella by direct transesterification using Novozym®435 as catalyst and ethanol as acyl acceptor; simultaneously optimizing the process by response surface methodology and enzyme reuse. RESULTS The best experimental conditions indicated by the empirical model were temperature 40 °C, oil:ethanol molar ratio 1:4.5 and catalyst concentration 9.5% for 24 h, reaching 85.4% fatty acid ethylic esters ( FAEE) yield. Tert-butanol used as co-solvent increased the ethyl esters yield from 18%, keeping a high FAEE yield (over 70%) for more than 3 cycles of enzyme reuse. CONCLUSIONS Rich miscella has great potential as a low cost feedstock for biodiesel production when Novozym®435 is used as catalyst, simultaneously introducing an environmentally friendly step by using the renewable solvent ethanol in the extraction and transesterification. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

A study was conducted to evaluate the effects of aluminum (Al) in nutrient solutions on the dry weight (DW) yield, Al and phosphorus (P) contents, and organic acid exudation in alfalfa (Medicago sativa L.). Four alfalfa cultivars ('Robust', 'Sceptre', 'Aquarius', and 'California-55') were grown in nutrient solution at pH 4.5 and 6.0, with (50 and 100 μM) and without Al. The results revealed that Al caused a significant reduction in DW, especially in pH 4.5 treatment. Organic acid exudation was affected by pH and Al treatments. Citrate and succinate exudation increased with the high Al treatment at pH 4.5. However, no relationship between pH and carboxylate exudation was observed at pH 6.0. Accumulation of P and Al in roots suggests the existence of an exclusion mechanism for Al in alfalfa. Selection of cultivars with enhanced organic exudation capacity in response to Al might be useful for alfalfa production in moderately acidic soils. [ABSTRACT FROM AUTHOR]

5-hydroxymethylfurfural (HMF) stands out among the chemical products derived from biomass as a building block in the chemical industry. The conventional production of HMF is usually carried out from fructose, glucose, or other monosaccharides as feedstock, but sugar beet molasses, a by-product of the sugar industry containing sucrose (45–55%), is promising. This exploratory study used three aqueous stock solutions and one biphasic system as the sources of sucrose. The dehydration of sucrose to 5-hydroxymethylfurfural was assisted by microwave heating and subcritical water conditions. The maximum yield of HMF was 27.8 mol % for the aqueous solution of synthetic sucrose at 80 min of treatment. Although HMF yield was 7.1 mol % in the aqueous sugar beet molasses solution, it increased 2-fold after clarification (15.1 mol %) and 1.6-fold in the biphasic system (11.4 mol %). These are favorable outcomes since this is an exploratory investigation. The pseudo-first-order model fitted experimental data from the conversion of the sucrose from the stock solutions, and kinetic parameters were estimated and compared. The estimated reaction rate constant showed that inversion of sucrose is faster than fructose dehydration to HMF, but the latter reaction was the rate-determining step only for the biphasic system. The maximum partition coefficient value was four between 40 min and 60 min of reaction, calculated at room temperature. These predictions help investigators to estimate conversions and selectivity when pilot plants need to be simulated. [ABSTRACT FROM AUTHOR]

The adsorption of 2,4-dichlorophenol (2,4-DCP) and pentachlorophenol (PCP) by a variable-charge soil from southern Chile was studied in a series of batch equilibration experiments. 2,4-DCP and PCP adsorption behavior was evaluated as a function of pH (pH values of 4.5, 6.0 and 7.5) in a 0.1M KCl (25°C) background solution for soil material collected at three different depths (0–20cm, 20–40cm, and 40–60cm). 2,4-DCP and PCP adsorption decreased with increasing soil pH, suggesting that the undissociated species were adsorbed more readily and that electrostatic repulsion may inhibit partitioning as pH increases. The PCP adsorption was greater than observed for 2,4-DCP and decreased with soil depth. Multiple regression analysis between K d and various soil properties indicated that the soil organic carbon content is a strong indicator of chlorophenol adsorption, and in addition to organic carbon, the soil pH is an important property controlling adsorption behavior. [Copyright &y& Elsevier]

Castor bean is found in Chile between the Arica and Parinacota and Maule regions and is one the most important industrial crops worldwide because of the presence of ricinoleic acid in its oil. However, there is little information about it in our country. In this study, we analyzed the oil content and fatty acid profiles of 17 castor bean Chilean accessions from the Metropolitana and Valparaíso regions. The seed-oil was extracted using the Soxhlet extraction process, and the fatty acid profiles were determined using the GC-FID method. The oil content in castor bean Chilean accessions ranged between 45.7% and 54.0%. Among the 17 accessions analyzed, H-15 had the highest oil content (54.0%; p < 0.05), whereas the H-10 and H-08 accessions had the lowest oil content, (45.7% and 45.9%, respectively; p < 0.05). Ricinoleic acid was the most abundant fatty acid (between 87.64% and 89.83%) in the seed-oil. The highest level of ricinoleic acid was found in the H-08 accession. This was only statistically higher (p < 0.05) for three accessions, whereas the H-04 accession had the lowest ricinoleic acid content. Although the H-08 accession registered one of the least abundant oil contents, it had the highest amount of ricinoleic acid. No significant correlation was found between oil content and ricinoleic acid. Our study suggests that oil content does not influence the castor oil fatty profile. The high oil content and ricinoleic acid level registered in castor bean Chilean accessions justify their production in Chile and their utilization for developing bio-based products. Furthermore, Chilean castor bean could grow in semi-arid lands. However, further field studies are needed to identify the cultivars best suited for Mediterranean conditions. [ABSTRACT FROM AUTHOR]

Antioxidants can be encapsulated to enhance their solubility or bioavailability or to protect them from external factors. Electrospinning has proven to be an excellent option for applications in nanotechnology, as electrospun nanofibers can provide the necessary environment for antioxidant encapsulation. Forty-nine papers related to antioxidants loaded onto electrospun nanofibers were categorized and reviewed to identify applications and new trends. Medical and food fields were commonly proposed for the newly obtained composites. Among the polymers used as a matrix for the electrospinning process, synthetic poly (lactic acid) and polycaprolactone were the most widely used. In addition, natural compounds and extracts were identified as antioxidants that help to inhibit free radical and oxidative damage in tissues and foods. The most recurrent active compounds used were tannic acid (polyphenol), quercetin (flavonoid), curcumin (polyphenol), and vitamin B6 (pyridoxine). The incorporation of active compounds in nanofibers often improves their bioavailability, giving them increased stability, changing the mechanical properties of polymers, enhancing nanofiber biocompatibility, and offering novel properties for the required field. Although most of the polymers used were synthetic, natural polymers such as silk fibroin, chitosan, cellulose, pullulan, polyhydroxybutyrate, and zein have proven to be proper matrices for this purpose. [ABSTRACT FROM AUTHOR]

The use of antioxidants such as curcumin (Cur) or quercetin (Que) in biomedical and biotechnological applications has been studied owing to their capability to prevent oxidative stress and inhibit free radicals. Using polyhydroxybutyrate (PHB) electrospun fibers is presented as a proper option to encapsulate curcumin and quercetin due to its biocompatibility and biodegradability characteristics. Electrospun fibers were obtained dissolving commercial PHB in chloroform: N , N -dimethylformamide (DMF) (4:1) at 7% m/V, and adding two different concentrations of antioxidant (Cur, and Que) 1%m/m, and 7% m/m. These polymeric solutions were electrospun at different conditions and the obtained fibers were characterized by scanning electron microscopy (SEM), thermogravimetric (TGA) analysis, and Fourier transform infrared spectroscopy (FT-IR). The curcumin and quercetin releases into phosphate buffer saline (PBS) at pH 7.4 were obtained in vitro and measured by spectrophotometry. Antioxidant activities were measured by spectrophotometry in a microplate reader using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Fibers obtained with different formulations presented a chemical composition in accordance with PHB according to FTIR spectra, the diameters fluctuate between 0.761 ± 0.123 and 1.803 ± 0.557 μm, with qualities over 0.95 according to their morphology, and the melting temperature resulted near 178 °C according to the bibliography. The crystallinity of fibers decreases while curcumin or quercetin concentration increases for the studied interval, indeed, quercetin showed a higher impact on the relative crystallinity of fibers. Antioxidant activity of active compounds is maintained after encapsulation in PHB electrospun fibers, and quercetin resulted in near four times antioxidant activity compared to curcumin according to DPPH analysis. • PHB is suitable for carrying quercetin and curcumin. • High quality and solvent-free microfibers are produced with PHB and antioxidants. • Antioxidant characteristics are maintained for the new material. [ABSTRACT FROM AUTHOR]

Thermal insulation materials play a significant role in improving the energy efficiency of buildings and therefore many studies focus their efforts on developing low environmental impact materials. In this context, the aim of this work was to study a natural polymer obtained from Hydrangea Macrophylla (HM) and its application as a thermal insulation material. The natural polymer was chemically, physically and mechanically characterized and compared to polyurethane (PU) and expanded polystyrene (EPS). In addition, a composite material blended in a mold using HM stems and sprayed with PU was used to evaluate possible applications. The results obtained from morphological studies conducted on HM showed it to be an interesting natural porous structure with a smooth surface similar to those found in closed cell insulation materials and highly compatible with PU foam. This composite showed good thermal stability, an outstanding thermal conductivity for a natural insulation material, high density and good behavior under compression. HM polymer in a PU matrix like a block type was shown to be an appropriate thermal insulation material, providing an excellent opportunity to reduce the environmental impacts of these types of insulating foams. [ABSTRACT FROM AUTHOR]