Liquid membrane extraction of bio-active amphiphilic substances: Recovery of surfactin

The interest of application of liquid membrane (pertraction) processes for recovery of biosurfactants from aqueous media was demonstrated. Transport of pure surfactin in three-liquid-phase system was studied. Surfactin was successfully extracted from slightly acid media (pH 5.65–6.05) applying batch pertraction in a rotating discs contactor and using n-heptane as liquid membrane. The process efficiencywas found to be strongly affected by the feed solution acidity (83% at pHF 6.05 and 97% at pHF 5.65 after 4 h pertraction). An atypical pH effect was observed when the behaviour of surfactin extraction from aqueous media by non-polar solvents (n-heptane and n-octane)was studied. The obtained high extraction degrees fromboth acid and basic media and the clearly reduced degree of extraction from neutral media could be attributed to the different conformations of surfactin in these media

Liquid membrane extraction lipopeptides

Liquid membrane extraction lipopeptide

Lipopeptide overproduction by cell immobilization on iron-enriched light polymer particles

The study concerns surfactin and/or fengycin batch production by immobilized cells of Bacillus subtilis ATCC 21332. Light carriers designed for a three phase inverse fluidized bed biofilm reactor (TPFIBR) were used. With respect to the biofilm reactor development, a new support based on iron grafting onto polypropylene foams has been proposed. A suspension solid-state grafting process was applied to graft ferric acetylacetonate onto polypropylene (PP) foams with a density of 0.3–0.7 g/cm3. The iron contents grafted onto PP increased with the reaction time and then it tended to level off. The iron contents at 7.5 and 10 h are 0.74 and 0.75 wt%, respectively. It was specified that the equilibrium was reached at 7.5 h. Influence of particles on lipopeptide production was analyzed in two kinds of experiments: preliminary colonization step of particles, followed by production step in modified culture medium (named in this work colonization step) or direct addition of pellets in culturemedium (named production step). All PP+ iron pellets promoted biomass enhancement. The production yield was modified for all types of PP supports, containing respectively 0, 0.35 and 0.75% of iron. The immobilized cultures produced 2.09–4.3 times more biosurfactants than planktonic cells. In production experiments addition of carriers seemed tomodify the ratio between surfactin and fengycin with an enhancement of the fengycin production. The highest concentration of fengycin was obtained with addition of pellets containing 0.35% of iron

Integrated process for production of surfactin Part 1: Adsorption rate of pure surfactin onto activated carbon

The work reported in this paper is aimed at studying the adsorption of surfactin from aqueous solution onto activated carbon. Among the factors,agitation rate, activated carbon particle-size, pH, temperature, initial adsorbate concentration, adsorbent amount and ionic strength of the solution were studied. Both adsorption equilibrium and kinetics showed that activated carbon acted as a suitable adsorbent for surfactin recovery. Two mechanisms represented by different kinetic models were examined, namely, the intraparticle diffusion one and the one involving chemisorption accompanied by surface coverage (conforming to the Elovich concept)

Integrated process for production of surfactin Part 2. Equilibrium and kinetic study of surfactin adsorption onto activated carbon

Previous work has presented kinetics of pure surfactin adsorption onto activated carbon. Being an efficient biosurfactant, the lipopeptide surfactin has been produced in a bioprocess supported by the strain Bacillus subtilis ATCC 21332. This work is aimed at studying surfactin recovery directly from the culture medium. A thermodynamic study is carried out. Referring to adsorption capacity, the thermodynamic study confirmed that the adsorption of pure surfactin is an exothermic process. The capacity of surfactin adsorption from culture media shows that the activated carbon could be used as efficient adsorbent for surfactin recovery in an integrated process. The study shows the importance of the temperature for process control. Aimed at fixed bed column design, surfactin adsorption modelling on a single microporous pellet is demonstrated

Interspecific and intergeneric somatic hybrids with C. deliciosa Ten. enlights non additive inheritance in allotetraploid citrus

Neoregulation of parental genome expression in allopolyploid plants contributes to the expression of new phenotypes. Somatic hybrids allow combining genomes without sexual recombination and are interesting models to study the immediate effect of allopolyploidisation on the regulation of gene expression and subsequent phenotype elaboration. While most of the citrus germplasm is diploid, somatic hybridization has become an integral part of citrus variety improvement programs aiming to create new allotetraploid rootstocks or to synthesize triploid hybrids by further sexual hybridization. By protoplast fusion CIRAD obtained allotetraploid hybrids between C. deliciosa and 6 others citrus species: 4 belong to Citrus genus (C. limon, lemon; C. aurantifolia, lime; C. sinensis, sweet orange; C. paradisi, grapefruit), 2 belong to Poncirus trifoliata (trifoliate orange) and Fortunella margarita (kumquat). Molecular analysis using 100 SSR markers did not reveal any inconsistency with total addition of parental genomes. Morphological description was done for leaves and fruits as well as the sugar and acid fruit contents. According to the traits and parental combination, codominance or dominance of one parent was observed and lead to conclude for an important contribution of interaction variance in phenotypic diversity elaboration. Analyze by GC-MS of the leaf volatile compounds of the same allotetraploid hybrids revealed a systematic global dominance of the mandarin profile. It was particularly marked regarding the absence of monoterpene aldehydes and monoterpene alcohols and the very low level of sesquiterpene hydrocarbons, sesquiterpene alcohols, and sesquiterpene aldehydes in all hybrids while these compounds were found at high concentrations for the non mandarin parents. 2-D electrophoresis analysis of the leaf proteome of two allotetraploid somatic hybrids combining C. deliciosa with C. aurantifolia and Fortunella margarita displayed a closer relation between the two allotetraploid hybrids and their mandarin parent than with the other parent. Similar results have been observed at transcriptome level in a genome-wide gene expression analysis on fruit pulp of allotetraploid between C. deliciosa and C. limon, using a Citrus 20 K cDNA microarray. The gene expression of the allotetraploid suggested a global dominance of the mandarin fruit pulp transcriptome. Particularly, genes down regulated in mandarin compared to lemon were also repressed in the allotetraploid hybrid. The study is now extended to an interspecific diallelic somatic hybridization scheme to have a wider understanding of genome interaction in allotetraploid citrus. (Texte intégral

Use of settlement patterns and geochemical tagging to test population connectivity of eastern oysters Crassostrea virginica

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gancel, H. N., Carmichael, R. H., Du, J., & Park, K. Use of settlement patterns and geochemical tagging to test population connectivity of eastern oysters Crassostrea virginica. Marine Ecology Progress Series, 673, (2021): 85–105, https://doi.org/10.3354/meps13796.Freshwater-dominated estuaries experience large fluctuations in their physical and chemical environments which may influence larval dispersal, settlement, and connectivity of populations with pelagic larval stages. We used settlement patterns and natural tagging along with numerical hydrodynamic model results to assess settlement and connectivity among oysters across the freshwater-dominated Mobile Bay-eastern Mississippi Sound (MB-EMS) system. Specifically, we (1) tested how freshwater inputs and associated environmental attributes influenced settlement patterns during high and low discharge conditions in 2014 and 2016, respectively, and (2) analyzed trace element (TE) ratios incorporated into multiple shell types (larval and settled shell of spat and adult shells) to determine if shells collected in situ incorporate temporally stable site-specific signatures. We also assessed if TE ratios compared between adult (TE natal signature proxy) and larval shells could infer connectivity. Larval settlement was 4× higher during low discharge than during high discharge when oyster larvae only settled in higher salinity regions (EMS). Spat and adult shells incorporated site-specific TE ratios that varied from weeks to months. Connectivity results (May-June 2016 only) suggest that EMS is an important larval source to EMS and lower MB. While we were able to infer probable connectivity patterns using adult and larval shells, more study is needed to assess the utility of adult shells as proxies for natal-location TE signatures. Results provide a baseline for measuring future larval connectivity and adult distribution changes in the MB-EMS system. Biological and geochemical data demonstrate the potential to identify environmental attributes that spatiotemporally mediate settlement and connectivity in dynamic systems.This work was funded by the Mississippi−Alabama Sea Grant Consortium (project number #R/ SFA-03) and the Food and Drug Administration and MESC/ Dauphin Island Sea Lab Collaboration (award numbers: 5U19FD005923-04 and 5U19FD004277-04)

Migration of polyphenols from natural and microagglomerated cork stoppers to hydroalcoholic solutions and their sensory impact

During bottling aging, the wine comes into contact with the cork stopper due to the horizontal position of the bottle. The release of compounds, such as cork phenolic compounds, thus take place between the cork and the wine, depending on the type of cork stopper and the surface treatments applied. Many publications describe the extraction of these phenolic compounds in wine or hydroalcoholic solutions from natural corks, but few address microagglomerated corks, which are increasingly used by winemakers to seal their bottles. The aim of this study was therefore to compare the polyphenols, mainly hydrolysable tannins, transferred from natural and microagglomerated corks treated with supercritical CO2 into hydroalcoholic solutions. For this purpose, polyphenols released in macerates of natural and microagglomerated cork stoppers were identified and quantified by HPLC-DAD-ESI-QQQ. Suberic acid was also quantified. In this study, despite the high intra-“natural cork stopper” variability, significant differences were found between both types of stoppers for all polyphenols, the agglomerated corks releasing significantly less polyphenols; i.e., 25 times less. In contrast, suberic acid was extracted from both types of corks in similar concentrations; therefore, its extractability was not impacted by the type of stopper. A sensory profile was also carried out on the macerates. Macerates of natural cork stoppers were perceived with notes of “cardboard, dust, plank, wood” and “cork taint” significantly higher than supercritical CO2 treated microagglomerated cork stopper macerates. Moreover, the natural cork macerate with the highest content in polyphenol was perceived as being more bitter than that of microagglomerated cork stoppers

Valorization of Grape Pomace: A Review of Phenolic Composition, Bioactivity, and Therapeutic Potential

Vitis vinifera L., commonly known as grapes, is one of the most widely cultivated crops worldwide, with over 80% used for wine production. However, the winemaking process generates substantial residues, including grape pomace (GP), wine lees, and wastewater, which can pose significant environmental and economic challenges. Among these, GP stands out not only as a waste product but also as a rich source of polyphenols—bioactive compounds with recognized antioxidant and anti-inflammatory properties. Recent advancements have expanded the application of GP-derived extracts, particularly in the health and food industries, due to their potent bioactive properties. This review provides a comprehensive overview of the valorization of GP, focusing on its phenolic composition and therapeutic potential. It evokes innovative, environmentally friendly extraction techniques and integrated methods for the chemical analysis of these valuable compounds. Additionally, the health benefits of GP polyphenols are explored, with recent experimental findings examining their metabolism and highlighting the key role of gut microbiota in these processes. These insights contribute to a deeper understanding of the biological activity of GP extracts and underscore their growing significance as a high-added-value product. By illustrating how winemaking by-products can be transformed into natural therapeutic agents, this review emphasizes the importance of sustainable development and eco-friendly waste management practices, significantly contributing to the advancement of a circular economy. © 2024 by the authors