Methyl oleate for plant protection products formulations: Enzymatic synthesis, reaction kinetics and application testing.

This study presents a solvent-free enzymatic approach for the synthesis of fatty acid methyl esters (FAMEs), such as methyl oleate, for their application as adjuvant in plant protection products (PPP) formulations. The direct esterification between free fatty acid and methanol was optimized to achieve 98% acid conversion. The kinetics of this conversion was accurately described by a simple second order mechanism and non-linear regression was applied to calculate the rate constants of the forward and backward reactions based on full progress curves data.

Toward Renewable-Based Prebiotics from Woody Biomass: Potential of Tailored Xylo-Oligosaccharides Obtained by Enzymatic Hydrolysis of Beechwood Xylan as a Prebiotic Feed Supplement for Young Broilers.

Although antibiotic resistance emerges naturally, this process has been accelerated by the worldwide overuse and misuse of antibiotics. It is essential to find effective alternatives in the broiler industry to improve poultry health while maintaining production efficiency and product safety. In this study, we aimed to evaluate a potential alternative: wood-derived xylo-oligosaccharides (XOS).

Selective Enzymatic Esterification of Lignin-Derived Phenolics for the Synthesis of Lipophilic Antioxidants.

Lignin is an abundant and renewable source of phenolic compounds that can be used as natural antioxidants to substitute synthetic, petroleum-based alternatives. The development of lignin depolymerization techniques has improved the accessibility of low-molecular-weight phenolic fractions with enhanced antioxidant activity compared to native lignin. The selective esterification of the aliphatic OH groups in these compounds is necessary in order to increase their compatibility with hydrophobic product matrixes, while preserving their antioxidant capacity.

Enzymatic Production of Xylo-oligosaccharides from Destarched Wheat Bran and the Impact of Their Degree of Polymerization and Substituents on Their Utilization as a Carbon Source by Probiotic Bacteria.

The enzymatic production of xylo-oligosaccharides (XOs) from destarched wheat bran with a GH11 xylanase was studied. Xylo-oligosaccharides (XOs) produced were separated into different fractions according to their degree of polymerization (DP) and the nature of their substituents: arabinoxylo-oligosaccharides (AXOs) with a DP from 2 to 3 and DP from 2 to 6 and feruloylated arabinoxylo-oligosaccharides (FAXOs) esterified by ferulic and -coumaric acids with a DP from 3 to 6. Both AXOs (short and long DP) and FAXOs stimulated the growth of , , and similarly but not .

Investigating Pervaporation for In Situ Acetone Removal as Process Intensification Tool in ω-Transaminase Catalyzed Chiral Amine Synthesis.

Hydrophobic pervaporation (PV), allowing for the separation of an organic component from an aqueous stream, was investigated for in situ acetone removal from a transamination reaction. A poly(dimethylsiloxane) membrane was applied in a coupled enzymatic process at 5 L scale. Among the four components, there was no loss of donor and product amines through PV which was highly desirable.

Continuous production of pectic oligosaccharides from sugar beet pulp in a cross flow continuous enzyme membrane reactor.

Sugar beet pulp pectin is an attractive source for the production of pectic oligosaccharides, an emerging class of potential prebiotics. The main aim of the present work was to investigate a new process allowing to produce pectic oligosaccharides in a continuous way by means of a cross flow enzyme membrane reactor while using a low-cost crude enzyme mixture (viscozyme). Preliminary experiments in batch and semi-continuous setups allowed to identify suitable enzyme concentrations and assessing filtration suitability.

Continuous production of pectic oligosaccharides from onion skins with an enzyme membrane reactor.

The aim of this research was to valorize onion skins, an under-utilized agricultural by-product, into pectic oligosaccharides (POS), compounds with potential health benefits. To achieve high hydrolysis performance with the multi-activity enzyme Viscozyme L, an innovative approach was investigated based on a cross-flow continuous membrane enzyme bioreactor (EMR). The influence of the various process conditions (residence time, enzyme concentration, substrate concentration) was investigated on productivity and yield.

Enzymatic pectic oligosaccharides (POS) production from sugar beet pulp using response surface methodology.

Pectic oligosaccharides (POS) have been indicated as novel candidate prebiotics. Traditionally, POS are produced from pectin-rich by-products using a two-step process involving extraction of the pectin, followed by its hydrolysis into POS. A one-step approach, in which the POS is directly produced from the raw material, might provide a more efficient alternative.

Contrasting dual (C, Cl) isotope fractionation offers potential to distinguish reductive chloroethene transformation from breakdown by permanganate.

cis-1,2-Dichloroethene (cis-DCE) and trichloroethene (TCE) are persistent, toxic and mobile pollutants in groundwater systems. They are both conducive to reductive dehalogenation and to oxidation by permanganate. In this study, the potential of dual element (C, Cl) compound specific isotope analyses (CSIA) for distinguishing between chemical oxidation and anaerobic reductive dechlorination of cis-DCE and TCE was investigated.

Geochemical and microbial community determinants of reductive dechlorination at a site biostimulated with glycerol.

Biostimulation is widely used to enhance reductive dechlorination of chlorinated ethenes in contaminated aquifers. However, the knowledge on corresponding biogeochemical responses is limited. In this study, glycerol was injected in an aquifer contaminated with cis-dichloroethene (cDCE), and geochemical and microbial shifts were followed for 265 days.

Enzymatic production of pectic oligosaccharides from onion skins.

Onion skins are evaluated as a new raw material for the enzymatic production of pectic oligosaccharides (POS) with a targeted degree of polymerization (DP). The process is based on a two-stage process consisting of a chelator-based crude pectin extraction followed by a controlled enzymatic hydrolysis. Treatment of the extracted crude onion skin's pectin with various enzymes (EPG-M2, Viscozyme and Pectinase) shows that EPG-M2 is the most appropriate enzyme for tailored POS production.

Enzymatic milk clotting activity in artichoke (Cynara scolymus) leaves and alpine thistle (Carduus defloratus) flowers. Immobilization of alpine thistle aspartic protease.

Two different milk clotting enzymes, belonging to the aspartic protease family, were extracted from both artichoke leaves and alpine thistle flowers, and the latter was covalently immobilized by using a polyacrylic support containing polar epoxy groups. Our findings showed that the alpine thistle aspartic protease was successfully immobilized at pH 7.0 on Immobeads IB-150P beads and that, under these experimental conditions, an immobilization yield of about 68% and a recovery of about 54% were obtained.

Effect of Extraction Conditions on the Saccharide (Neutral and Acidic) Composition of the Crude Pectic Extract from Various Agro-Industrial Residues.

The influence of different extraction methodologies was assessed on the composition of both neutral (arabinose, rhamnose, galactose) and acidic (galacturonic acid) pectic polysaccharides obtained from four agro-industrial residues, namely, berry pomace (BP), onion hulls (OH), pressed pumpkin (PP), and sugar beet pulp (SBP). For acidic pectic polysaccharides, the extraction efficiency was obtained as BP (nitric acid-assisted extraction, 2 h, 62.9%), PP (enzymatic-assisted extraction, 12 h, 75.

Impact of a wastewater treatment plant on microbial community composition and function in a hyporheic zone of a eutrophic river.

The impact of the installation of a technologically advanced wastewater treatment plant (WWTP) on the benthic microbial community of a vinyl chloride (VC) impacted eutrophic river was examined two years before, and three and four years after installation of the WWTP. Reduced dissolved organic carbon and increased dissolved oxygen concentrations in surface water and reduced total organic carbon and total nitrogen content in the sediment were recorded in the post-WWTP samples. Pyrosequencing of bacterial 16S rRNA gene fragments in sediment cores showed reduced relative abundance of heterotrophs and fermenters such as Chloroflexi and Firmicutes in more oxic and nutrient poor post-WWTP sediments.

Biodegradation: Updating the concepts of control for microbial cleanup in contaminated aquifers.

Biodegradation is one of the most favored and sustainable means of removing organic pollutants from contaminated aquifers but the major steering factors are still surprisingly poorly understood. Growing evidence questions some of the established concepts for control of biodegradation. Here, we critically discuss classical concepts such as the thermodynamic redox zonation, or the use of steady state transport scenarios for assessing biodegradation rates.

Pectic oligosaccharides from agricultural by-products: production, characterization and health benefits.

Pectin containing agricultural by-products are potential sources of a new class of prebiotics known as pectic oligosaccharides (POS). In general, pectin is made up of homogalacturonan (HG, α-1,4-linked galacturonic acid monomers) and rhamnogalacturonan (RG, alternate galacturonic acid and rhamnose backbone with neutral side chains). Controlled hydrolysis of pectin containing agricultural by-products like sugar beet, apple, olive and citrus by chemical, enzymatic and hydrothermal can be used to produce oligo-galacturonides (GalpOS), galacto-oligosaccharides (GalOS), rhamnogalacturonan-oligosaccharides (RGOS), etc.

Quantitative and functional dynamics of Dehalococcoides spp. and its tceA and vcrA genes under TCE exposure.

This study aimed at monitoring the dynamics of phylogenetic and catabolic genes of a dechlorinating enrichment culture before, during, and after complete dechlorination of chlorinated compounds. More specifically, the effect of 40 μM trichloroethene (TCE) and 5.6 mM lactate on the gene abundance and activity of an enrichment culture was investigated for 40 days.

Kinetics of dechlorination by Dehalococcoides mccartyi using different carbon sources.

Stimulated anaerobic dechlorination is generally considered a valuable step for the remediation of aquifers polluted with chlorinated ethenes (CEs). Correct simulation and prediction of this process in situ, however, require good knowledge of the associated biological reactions. The aim of this study was to evaluate the dechlorination reaction in an aquifer contaminated with trichloroethene (TCE) and its daughter products, discharging into the Zenne River.

Determinants of the microbial community structure of eutrophic, hyporheic river sediments polluted with chlorinated aliphatic hydrocarbons.

Chlorinated aliphatic hydrocarbons (CAHs) often discharge into rivers as contaminated groundwater baseflow. As biotransformation of CAHs in the impacted river sediments might be an effective remediation strategy, we investigated the determinants of the microbial community structure of eutrophic, CAH-polluted sediments of the Zenne River. Based on PCR-DGGE analysis, a high diversity of Bacteria, sulfate-reducing bacteria, Geobacteraceae, methanogenic archaea, and CAH-respiring Dehalococcoides was found.

Microbial dechlorination activity during and after chemical oxidant treatment.

Potassium permanganate (PM) and sodium persulfate (PS) are used in soil remediation, however, their compatibility with a coinciding or subsequent biotreatment is poorly understood. In this study, different concentrations of PM (0.005-2g/L) and PS (0.

Evaluation of solid polymeric organic materials for use in bioreactive sediment capping to stimulate the degradation of chlorinated aliphatic hydrocarbons.

In situ bioreactive capping is a promising technology for mitigation of surface water contamination by discharging polluted groundwater. Organohalide respiration (OHR) of chlorinated ethenes in bioreactive caps can be stimulated through incorporation of solid polymeric organic materials (SPOMs) that provide a sustainable electron source for organohalide respiring bacteria. In this study, wood chips, hay, straw, tree bark and shrimp waste, were assessed for their long term applicability as an electron donor for OHR of cis-dichloroethene (cDCE) and vinyl chloride (VC) in sediment microcosms.

Small-scale oxygen distribution determines the vinyl chloride biodegradation pathway in surficial sediments of riverbed hyporheic zones.

Surficial riverbed sediments are often characterized by sharp redox gradients between the aerobic benthic sediment and underlying anoxic sediment, potentially representing an ideal niche for aerobic and anaerobic vinyl chloride (VC) degraders. To test this, the fate of VC in aerobic and anaerobic microcosms containing surficial sediment of a riverbed hyporheic zone receiving VC-contaminated groundwater was explored. Quantitative PCR showed that Dehalococcoides 16S rRNA gene and VC reductive dehalogenase-encoding genes (vcrA, bvcA) were highly enriched in anaerobic microcosms, with stoichiometric conversion of VC to ethene.

Temporal variations in natural attenuation of chlorinated aliphatic hydrocarbons in eutrophic river sediments impacted by a contaminated groundwater plume.

Chlorinated aliphatic hydrocarbons (CAHs) often discharge into rivers as contaminated groundwater baseflow. Biotransformation, sorption and dilution of CAHs in the impacted river sediments have been reported to reduce discharge, but the effect of temporal variations in environmental conditions on the occurrence and extent of those processes in river sediments is largely unknown. We monitored the reduction of CAH discharge into the Zenne River during a 21-month period.