Surfactant Production Research Articles

Complex Micellization Behavior of the Polysorbates Tween 20 and Tween 80.

Polysorbates (PSs, Tweens) are widely used surfactant products consisting of a sorbitan ring connecting up to four ethylene oxide (EO) chains of variable lengths, one or more of which are esterified with fatty acids of variable lengths and saturation degrees. Pharmaceutical applications include the stabilization of biologicals in solutions and the solubilization of poorly water soluble, active ingredients. This study characterizes the complex association behavior of compendial PSs PS20 and PS80, which is fundamentally different from that of single-component surfactants. To this end, a series of demicellization experiments of isothermal titration calorimetry with different PS concentrations are evaluated. Their experiment-dependent heats of titration are converted into a common function of the state of a sample, the micellar enthalpy Qm(c). These functions demonstrate that initial micelles are already present at the lowest concentrations investigated, 2 μM for PS20 and 10 μM for PS80. Initial micelles consist primarily of the surfactant species with the lowest individual critical micelle concentration (cmc). With increasing concentration, the other PS species gradually enter these micelles in the sequence of increasing individual cmc's and hydrophilic-lipophilic balance. Concentration ranges with pronounced slopes of Qm(c) can be tentatively assigned to the uptake of the major components of the PS products. Micellization and the variation of the micelle properties progress up to at least 10 mM PS. That means the published cmc values or ranges of PS20 and PS80 may be related to certain, major components being incorporated into and forming specific micelles but must not be interpreted in terms of an absence of micelles below and constant properties, e.g., the surface activity, of the micelles above these ranges. The micellization enthalpy curves differ quite substantially between PS20 and PS80 and, in a subtler fashion, between individual quality grades such as high purity, pure lauric acid/pure oleic acid, super-refined, and China grade.

Role of NRF2 in immune modulator expression in developing lung.

After birth, the alveolar epithelium is exposed to environmental pathogens and high O2 tensions. The alveolar type II cells may protect this epithelium through surfactant production. Surfactant protein, SP-A, an immune modulator, is developmentally upregulated in fetal lung with surfactant phospholipid synthesis. Herein, we observed that the redox-regulated transcription factor, NRF2, and co-regulated C/EBPβ and PPARγ, were markedly induced during cAMP-mediated differentiation of cultured human fetal lung (HFL) epithelial cells. This occurred with enhanced expression of immune modulators, SP-A, TDO2, AhR, and NQO1. Like SP-A, cAMP induction of NRF2 was prevented when cells were exposed to hypoxia. NRF2 knockdown inhibited induction of C/EBPβ, PPARγ, and immune modulators. Binding of endogenous NRF2 to promoters of SP-A and other immune modulator genes increased during HFL cell differentiation. In mouse fetal lung (MFL), a developmental increase in Nrf2, SP-A, Tdo2, Ahr, and Nqo1 and decrease in Keap1 occurred from 14.5 to 18.5dpc. Developmental induction of Nrf2 in MFL was associated with increased nuclear localization of NF-κB p65, a decline in p38 MAPK phosphorylation, increase in the MAPK phosphatase, DUSP1, induction of the histone acetylase, CBP, and decline in the histone deacetylase, HDAC4. Thus, together with surfactant production, type II cells protect the alveolar epithelium through increased expression of NRF2 and immune modulators to prevent inflammation and oxidative stress. Our findings further suggest that lung cancer cells have usurped this developmental pathway to promote immune tolerance and enhance survival.

Immunohistochemical findings in the lungs of COVID-19 subjects: evidence of surfactant dysregulation.

Acute respiratory distress syndrome (ARDS) is characterized by quantitative and qualitative changes in surfactant composition, leading to surfactant dysregulation with alveolar collapse and acute respiratory hypoxic failure. Recently, surfactant has been hypothesized to play a relevant role in COVID-19, representing a strong defender against SARS-CoV-2 infection. The aim of our work was the study of immunohistochemical surfactant expression in the lungs of patients died following SARS-CoV-2 ARDS, in order to shed light on a possible therapeutic surfactant administration. We investigated four patients who died due to ARDS following SARS-COV-2 infection and four patients submitted to lung biopsy, in the absence of SARS-CoV-2 infection. In all 8 cases, lung specimens were immunostained with anti-surfactant protein A (SP-A) and B (SP-B). In control subjects, reactivity for SP-B was restricted to type II alveolar cells. Immunostaining for SP-A was observed on the surface of alveolar spaces. In the COVID-19 positive lungs, immunoreactivity for SP-B was similar to that observed in control lungs; SP-A was strongly expressed along the alveolar wall. Moreover, dense aggregates of SP-A positive material were observed in the alveolar spaces. Our immunohistochemical data show the dysregulation of surfactant production in COVID-19 patients, particularly regarding SP-A expression. The increased presence of SP-A in condensed masses inside alveolar spaces could invalidate the therapeutic efficacy of the treatment with exogenous surfactant.

Enhanced environment friendly surfactant production by the glycerolysis of castor oil using amino acid ionic liquid as a catalyst

Monoacylglycerol (MAG) is one kind of the oil-based nonionic surfactant, which has the excellent emulsifying property and biodegradability. In this work, several novel and green amino acid ionic liquids (AAILs) were developed as eco-friendly catalysts to promote the glycerolysis of castor (Ricinus communis L.) oil for the green castor oil-based MAG production. Nine AAILs, consisting of an amino acid anion (arginine (Arg), lysine (Lys) and histidine (His)), and an organic hydroxide cation (choline hydroxide (ChOH), tetramethylhydroxide ammonium (TMAOH) and tetrabutylammonium hydroxide (TBAOH)), were synthesized by a simple and green chemical route and used as catalysts to catalyze the glycerolysis of castor oil. Effects of the structural composition of AAILs, reaction time (0-120 min), castor oil and glycerol molar ratio (1:2-1:10), AAIL load (4-12%), and temperature (60-120℃) on the glycerolysis were evaluated and optimized by Box–Behnken methodology. Particularly, the effect of free fatty acid content in castor oil (0-25%) was also investigated to analyze the fatty acid tolerance of AAILs. Among the tested AAILs, [Ch][Arg], [TMA][Arg], and [TBA][Arg] showed the outstanding catalysis performance. Especially, [Ch][Arg] as reaction catalyst for the glycerolysis of castor oil exhibited the best catalysis activity, and high selectivity for MAG formation. The maximum TAG conversion (99.6 ± 0.4%) and MAG content (83.3 ± 1.6%) were obtained under the optimized conditions: 93.7℃, 60.7 min, [Ch][Arg] load 12.3%, and substrate molar ratio 1:6.4. Besides, [Ch][Arg] still had 80% catalytic activity when the free fatty acid content was 20% in castor oil. Kinetic analysis of the glycrolysis was also evaluated. Accordingly, activation energy (Ea) and average reaction order (a) of the glycerolysis were obtained as 59.7 kJ/mol and 1.69, respectively.

The effect of ultrasound-guided intraperitoneal injection of ulinastatin on lung development in intrauterine growth-restricted fetal rabbits

Objectives To investigate the effect and mechanism of ulinastatin (UTI) on development of lungs in fetal rabbits with intrauterine growth retardation (IUGR). Methods Twenty pregnant rabbits were equally divided into normal, IUGR, UTI, and LY groups. The normal group was only injected with saline and marked with tattoo ink. IUGR models were established by injecting N-nitro-L-arginine methyl ester in the rabbits of IUGR, UTI, and LY groups. The three groups were injected with saline, UTI, or UTI + LY294002 (PI3K inhibitor) respectively, and then marked with tattoo ink. After cesarean section, neonatal weights, and levels of dipalmitoyl phosphatidylcholine (DPPC), nitric oxide (NO), P-Akt, P-eNOS, and pulmonary surfactant-associated protein A (SP-A) were determined in tissues of the lungs. Radial alveoli count (RAC), pulmonary interstitial ratio, and ultrastructural changes in type II alveolar epithelial cells (AEC II) were also determined through light and electron microscopy. Results Compared with control, the IUGR group showed significantly decreased weight, RAC, lamellar bodies in AEC II, and levels of P-Akt, P-eNOS, DPPC, NO, and SP-A, and increased pulmonary interstitial ratio (p < .05). The UTI treatment did not affect the weight; however, all other parameters were opposite to those observed in the IUGR group (p < .05). Furthermore, these UTI-mediated changes were inhibited by LY294002. Conclusions Intraperitoneal UTI injection can promote the development of lungs and increase pulmonary surfactant production in IUGR fetal rabbits, potentially by activating PI3K/Akt/eNOS/NO signaling.

FGF10 and Lipofibroblasts in Lung Homeostasis and Disease: Insights Gained From the Adipocytes.

Adipocytes not only function as energy depots but also secrete numerous adipokines that regulate multiple metabolic processes, including lipid homeostasis. Dysregulation of lipid homeostasis, which often leads to adipocyte hypertrophy and/or ectopic lipid deposition in non-adipocyte cells such as muscle and liver, is linked to the development of insulin resistance. Similarly, an altered secretion profile of adipokines or imbalance between calorie intake and energy expenditure is associated with obesity, among other related metabolic disorders. In lungs, lipid-laden adipocyte-like cells known as lipofibroblasts share numerous developmental and functional similarities with adipocytes, and similarly influence alveolar lipid homeostasis by facilitating pulmonary surfactant production. Unsurprisingly, disruption in alveolar lipid homeostasis may propagate several chronic inflammatory disorders of the lung. Given the numerous similarities between the two cell types, dissecting the molecular mechanisms underlying adipocyte development and function will offer valuable insights that may be applied to, at least, some aspects of lipofibroblast biology in normal and diseased lungs. FGF10, a major ligand for FGFR2b, is a multifunctional growth factor that is indispensable for several biological processes, including development of various organs and tissues such as the lung and WAT. Moreover, accumulating evidence strongly implicates FGF10 in several key aspects of adipogenesis as well as lipofibroblast formation and maintenance, and as a potential player in adipocyte metabolism. This review summarizes our current understanding of the role of FGF10 in adipocytes, while attempting to derive insights on the existing literature and extrapolate the knowledge to pulmonary lipofibroblasts.

Development of Ultralow Interfacial Tension Lignosulfonate from Kraft Black Liquor for Enhanced Oil Recovery

Indonesia aims to implement large-scale enhanced oil recovery (EOR) to increase the national oil production. Chemical EOR is a promising technology to boost the production of old reservoirs with the aid of surfactants and polymers. Thus, the production of low-cost EOR surfactants from local resources with acceptable performance is highly attractive. The objective of the present work was to demonstrate the development of low-cost lignosulfonate surfactant production from kraft black liquor (BL). First, lignin was isolated from black liquor using a novel CO2 bubbling technique, followed by addition of coagulants. Next, sodium lignosulfonate (SLS) was synthesized from the resulting lignin, followed by formulation of SLS with octanol and palm fatty acid distillate (PFAD) soap to obtain an ultralow interfacial tension (IFT) surfactant. The initial IFT value of the SLS solution was already high at 0.7 mN/m. After formulation, the composition SLS:PFAD soap:octanol = 70:22:8 (wt%) improved the IFT value to 3.1 10-3 mN/m. An ultralow IFT in the range of 10-3 mN/m as achieved here fulfills the required IFT value for EOR surfactant.

Production of Biosurfactants by Ascomycetes.

Surfactants are utilized to reduce surface tension in aqueous and nonaqueous systems. Currently, most synthetic surfactants are derived from petroleum. However, these surfactants are usually highly toxic and are poorly degraded by microorganisms. To overcome these problems associated with synthetic surfactants, the production of microbial surfactants (called biosurfactants) has been studied in recent years. Most studies investigating the production of biosurfactants have been associated mainly with bacteria and yeasts; however, there is emerging evidence that those derived from fungi are promising. The filamentous fungi ascomycetes have been studied for the production of biosurfactants from renewable substrates. However, the yield of biosurfactants by ascomycetes depends on several factors, such as the species, nutritional sources, and environmental conditions. In this review, we explored the production, chemical characterization, and application of biosurfactants by ascomycetes.

Screening High-Temperature Foams with Microfluidics for Thermal Recovery Processes

Thermal recovery processes, and in particular, Steam-assisted gravity drainage (SAGD), are the most common and practical in situ technology for bitumen extraction. While SAGD is effective, steam injection results in poor steam chamber growth and distribution with poor conformance specifically in areas with poor formation geology and bedding properties. These factors result in economic and environmental costs. Co-injecting foaming surfactants with noncondensable gases along with steam is an alternative solution to control the steam chamber behavior and its advancement throughout the formation. Selecting appropriate foaming surfactants is essential for successful implementation of a foam-steam processes. Conventional laboratory methods provide some indication of foaming surfactant performance but fail to reflect reservoir conditions and time scales. Microfluidics is well suited to assess the relevant pore-scale performance of foaming surfactants, at relevant conditions, with tight control over experimental parameters. Here, we develop a microfluidic approach to generate nitrogen-foam and assess stability and mobility control performance at relevant temperature (>150 °C) with results compared to those of traditional bulk foam analysis. The microconfinement associated with porous media creates more stable foam at reservoir-relevant temperatures and pressures. Direct visualization of the foaming dynamics, subsequent stability, and mobility testing in porous media provide a rapid assessment of foam performance as well as a diagnostic of surfactant product failures such as precipitation and phase decomposition, findings that directly informed pilot operations here. This screening also enables down-selection of the most promising agents for subsequent testing with candidate reservoir oil, in conventional cores or micromodels.

Effectiveness of ZYESAMI™ (Aviptadil) in Accelerating Recovery and Shortening Hospitalization in Critically-Ill Patients with COVID-19 Respiratory Failure: Interim Report from a Phase 2B/3 Multicenter Trial

Background: There is currently no effective drug to treat critically-ill patients with COVID-19 Respiratory Failure. Vasoactive Intestinal Peptide (VIP) blocks intracellular replication of the SARS-CoV-2 virus, inhibits cytokine synthesis, prevents cytopathy, and upregulates surfactant production in human alveolar type II cells, which are the site of SARS-CoV-2 infection in the lung. Purpose: To determine the safety and efficacy of intravenous ZYESAMI™ (Aviptadil; synthetic Vasoactive Intestinal Peptide) for improving recovery from respiratory failure in patients with Respiratory Failure in Critical COVID-19.Methods: Randomized prospective double-blind placebo-controlled trial with 28 day and 60 day endpoints. Setting: Ten US-based acute care hospitals, which included 4 tertiary care teaching hospitals and 6 regional hospitals. Participants: 196 patients with PCR+ Critical COVID-19 treated with High Flow Nasal Cannula (HFNC: n=127) Non-Invasive Ventilation (NIV: n=32) or Mechanical Ventilation (MV: n=36). Intervention: Participants were randomly allocated to intravenous aviptadil (synthetic VIP) or placebo at a 2:1 ratio, in addition to maximal standard of care (SOC). Participants received 3 successive 12-hour intravenous infusions of Aviptadil at 50/100/150 pmol/kg/hr or normal saline placebo, each day for 3 consecutive days. The main outcome measure was cumulative probability of time to recovery from respiratory failure without relapse and with survival through day 28 and through day 60. Secondary endpoints included time to ICU discharge, time to hospital discharge, NIAID ordinal scale, and survival lifetable. Analysis was by intent to treat.Results: Overall, 91 of 131 Aviptadil-treated participants survived to day 28 compared to 47 of 65 placebo-treated patients (70.6% vs 71.7%; P=NS). Among those treated with HFNC (n=127), the main outcome measure demonstrated a trend in favor of the drug treated group (Hazard Ratio 1.53; P=.08). Participants treated in tertiary care hospitals demonstrated a greater effect (HR 1.84; P=.058). A 10 day median difference in hospital length of stay was seen in all HFNC patients (P=.006) and a thirteen day difference was seen in those treated in tertiary care centers (P=.004), with both differences favoring treatment with aviptadil. No drug-related serious adverse events were seen in either group. The only adverse event reported more frequently in drug- vs. placebo-treated participants was mild to moderate diarrhea (30% vs 1.5% P

New therapy by surfactant to avoid neuro/psychiatric problems caused by cerebral hypoxia

IntroductionCovid-19 causes neuro/psychiatric problems by cerebral hypoxia.ObjectivesMy therapy could allow us to cross Covid-19 infection by minimizing both immediate and chronic lung damage and would avoid many deaths and neuro/psychiatric problems from cerebral hypoxia.MethodsIn the case of a Covid-19 lung infection, the virus infects type II alveolar cells which consequently reduce the production of pulmonary surfactant. The surfactant has the function of reducing the surface tension of the alveoli. The less pulmonary surfactant there is, the more the alveoli tend to collapse due to the increased surface tension of their surface. Consequently, the lung would tend to collapse, that is, to reduce its volume, but collapse is prevented by the muscular movement of inspiration, which instead increases its volume. This means that a “low-pressure area” is created in the interstitial space which attracts liquid and substances which are often inflammatory and which organize over time, giving rise to interstitial pneumonia.ResultsI propose to administer the pulmonary surfactant to the patient Covid-19 in the presence of dyspnea and certainly during assisted ventilation. This technique is routinely used in preterm infants suffering from lack of pulmonary surfactant production due to the immaturity of type II alveolar cells, pending that once matured these cells produce it autonomously.ConclusionsSimilarly, the administration of surfactant during Covid-19 lung infection would allow the correct amount of surfactant to be maintained during the acute phase of the infection and would give time for type II alveolar cells to heal and independently resume surfactant production.DisclosureNo significant relationships.

Antenatal Corticosteroids: Extending the Practice for Late-Preterm and Scheduled Early-Term Deliveries?

Respiratory distress in late-preterm and early term infants generally may warrant admission to a special care nursery or an intensive care unit. In particular, respiratory distress syndrome and transient tachypnea of the newborn are the two most common respiratory morbidities. Antenatal corticosteroids (ACS) facilitate surfactant production and lung fluid resorption. The use of ACS has been proven to be beneficial for preterm infants delivered at less than 34 weeks’ gestation. Literature suggests that the benefits of giving antenatal corticosteroids may extend to late-preterm and early term infants as well. This review discusses the short-term benefits of ACS administration in reducing respiratory morbidities, in addition to potential long term adverse effects. An update on the current practices of ACS use in pregnancies greater than 34 weeks’ gestation and considerations of possibly extending versus restricting this practice to certain settings will also be provided.

Transformation of Pectins into Non-Ionic or Anionic Surfactants Using a One-Pot and Cascade Mode Process.

The present article describes the one-pot synthesis of double- and single-tailed surfactants by a cascade process that involves the hydrolysis/butanolysis of pectins into butyl galacturonate monosaccharides followed by transesterification/transacetalisation processes with fatty alcohols, and subsequent aqueous basic and acid treatments. The cascade mode allows the depolymerisation to proceed more efficiently, and the purification conditions are optimised to make the production of single-tailed surfactants more manufacturable. These products in a pure form or as mixtures with alkyl glycosides resulting from butanolysis and transglycosylation of pectin-derived hexoses, exhibit attractive surface-tension properties, especially for the n-oleyl ᴅ-galactosiduronic acid products. In addition, a readily biodegradability and an absence of aquatic ecotoxicity are shown for the galacturonic acid derivatives possessing an oleyl alkyl chain at the anomeric position.

Stimulation of Bacillus sp. by lipopeptide biosurfactant for the degradation of aromatic amine 4-Chloroaniline

This study aims to reveal that the biosurfactant act as a stimulant in aromatic amine 4-Chloroaniline (4-CA) degradation. Isolated degrading strain Bacillus sp. was used for the production of biosurfactant with help of substrate such as engine oil. The surfactant production by the strain was studied by using various screening methods and the results showed best emulsification activity (75%), surface tension reduction activity (28.6 mNm−1) and oil spreading activity (5.9 cm). The obtained surfactant was characterized using Fourier transform infrared spectroscopy (FT-IR), Gas chromatography-Mass Spectrometry (GC-MS), Matrix-Assisted Laser Desorption/ Ionization Time of Flight (MALDI-TOF) which confirmed that the nature of surfactant is lipopeptide. The maximum removal of 4-CA was achieved in different environmental conditions at concentration 100 mg L−1, neutral pH and temperature 30 °C. In the degradation studies, the 4-CA was removed upto 76% by Bacillus sp but in the presence of lipopeptide surfactant, the Bacillus sp removed 4-CA upto 100%. The degraded metabolites were further characterized using High-Pressure Liquid Chromatography (HPLC) and GC-MS. This research indicated that strain Bacillus sp along with the lipopeptide biosurfactant possesses higher potential in the bioremediation of 4-CA compound from the environment.

Production of green surfactants: Market prospects

Science has greatly contributed to the advancement of technology and to the innovation of production processes and their applications. Cleaning products have become indispensable in today’s world, as personal and environmental hygiene is important to all societies worldwide. Such products are used in the home, in most work environments and in the industrial sectors. Most of the detergents on the market are synthesised from petrochemical products. However, the interest in reducing the use of products harmful to human health and the environment has led to the search for detergents formulated with natural, biodegradable surfactant components of biological (plant or microbiological) origin or chemically synthesised from natural raw materials usually referred to as green surfactants. This review addresses the different types, properties, and uses of surfactants, with a focus on green surfactants, and describes the current scenario as well as the projections for the future market economy related to the production of the different types of green surfactants marketed in the world. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabla normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0cm; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri,sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Times New Roman; mso-bidi-theme-font:minor-bidi;}

CHARACTERIZATION OF A Microbacterium sp. STRAIN ISOLATED FROM SOILS CONTAMINATED WITH HYDROCARBONS IN THE BURGOS BASIN, MEXICO

The development of novel bioremediation strategies has focused on the isolation and identification of microorganisms that can thrive in polluted environments to evaluate their potential as biotechnological tools in bioremediation techniques. In this work, a bacterium isolated from hydrocarbon-contaminated soils from the Burgos basin was identified and its hydrocarbon degradation potential was evaluated. Identification based on sequencing the 16S rRNA gene identified one of the isolates (R3) as Microbacterium petrolearium. This strain was mainly antibiotic-sensitive with elevated carbohydrate assimilation differing from previously reported strains. Moderate surfactant production (I24 = 22.97 %) was observed, which was absent in a cell-free extract. M. petrolearium R3 showed increased growth that correlated with pollutant concentration. For light crude oil, at a higher contaminant percentage, the R3 strain showed increased growth; however, in the case of diesel, no growth was detected. The aforementioned data indicate that M. petrolearium strain R3, isolated from local sources, has potential use as a tool for hydrocarbon-contaminated soil bioremediation.

Utilization of Virgin Coconut Oil that has been Extracted in Phenolic Compounds as Resource of Diethanolamide

One of the vegetable oils that can be used as a surfactant is extracts of phenolic compounds from virgin coconut oil (VCO) or VCO residue.The purpose of this study was to make surfactants from VCO residue and to obtain the correct ratio of reactants and the appropriate concentration of NaOH catalyst to produce diethanolamide surfactant.The materials used are methyl ester from VCO residue and dietanolamine with NaOH catalyst. The amidation process uses a mole ratio of dietanolamine and methyl ester (1:1, 1.25: 1, 1.5: 1, 1.75: 1 and 2: 1) at a temperature of 160 ° C for 3 hours, and a NaOH catalyst with a concentration of 0.25, 0.5, and 0.75%.The results showed that the treatment of the ratio of methyl ester and diethanolamine and the concentration of NaOH catalyst produced DEA surfactant with the same consistency, namely a semi-solid viscous liquid with a clear yellow color.The higher the concentration of catalyst, the yield tends to increase.. All DEA surfactant products have a pH of 10, with viscosities ranging from 252.47 - 509.89 cP, soaping numbers ranging from 35.22 - 52.95 mg KOH / g, and glycerol levels from 0.08 to 29%.

SARS-CoV-2 Infection and Disease Modelling Using Stem Cell Technology and Organoids.

In this Review, we briefly describe the basic virology and pathogenesis of SARS-CoV-2, highlighting how stem cell technology and organoids can contribute to the understanding of SARS-CoV-2 cell tropisms and the mechanism of disease in the human host, supporting and clarifying findings from clinical studies in infected individuals. We summarize here the results of studies, which used these technologies to investigate SARS-CoV-2 pathogenesis in different organs. Studies with in vitro models of lung epithelia showed that alveolar epithelial type II cells, but not differentiated lung alveolar epithelial type I cells, are key targets of SARS-CoV-2, which triggers cell apoptosis and inflammation, while impairing surfactant production. Experiments with human small intestinal organoids and colonic organoids showed that the gastrointestinal tract is another relevant target for SARS-CoV-2. The virus can infect and replicate in enterocytes and cholangiocytes, inducing cell damage and inflammation. Direct viral damage was also demonstrated in in vitro models of human cardiomyocytes and choroid plexus epithelial cells. At variance, endothelial cells and neurons are poorly susceptible to viral infection, thus supporting the hypothesis that neurological symptoms and vascular damage result from the indirect effects of systemic inflammatory and immunological hyper-responses to SARS-CoV-2 infection.

Biosurfactants Produced by Phyllosphere-Colonizing Pseudomonads Impact Diesel Degradation but Not Colonization of Leaves of Gnotobiotic Arabidopsis thaliana.

Biosurfactant production is a common trait in leaf surface-colonizing bacteria that has been associated with increased survival and movement on leaves. At the same time, the ability to degrade aliphatics is common in biosurfactant-producing leaf colonizers. Pseudomonads are common leaf colonizers and have been recognized for their ability to produce biosurfactants and degrade aliphatic compounds. In this study, we investigated the role of biosurfactants in four non-plant-pathogenic Pseudomonas strains by performing a series of experiments to characterize their surfactant properties and their role during leaf colonization and diesel degradation. The biosurfactants produced were identified using mass spectrometry. Two strains produced viscosin-like biosurfactants, and the other two produced massetolide A-like biosurfactants, which aligned with the phylogenetic relatedness between the strains. To further investigate the role of surfactant production, random Tn5 transposon mutagenesis was performed to generate knockout mutants. The knockout mutants were compared to their respective wild types with regard to their ability to colonize gnotobiotic Arabidopsis thaliana and to degrade diesel or dodecane. It was not possible to detect negative effects during plant colonization in direct competition or individual colonization experiments. When grown on diesel, knockout mutants grew significantly slower than their respective wild types. When grown on dodecane, knockout mutants were less impacted than during growth on diesel. By adding isolated wild-type biosurfactants, it was possible to complement the growth of the knockout mutants.IMPORTANCE Many leaf-colonizing bacteria produce surfactants and are able to degrade aliphatic compounds; however, whether surfactant production provides a competitive advantage during leaf colonization is unclear. Furthermore, it is unclear if leaf colonizers take advantage of the aliphatic compounds that constitute the leaf cuticle and cuticular waxes. Here, we tested the effect of surfactant production on leaf colonization, and we demonstrate that the lack of surfactant production decreases the ability to degrade aliphatic compounds. This indicates that leaf surface-dwelling, surfactant-producing bacteria contribute to degradation of environmental hydrocarbons and may be able to utilize leaf surface waxes. This has implications for plant-microbe interactions and future studies.

Genetic disorders of the surfactant system: focus on adult disease.

Genes involved in the production of pulmonary surfactant are crucial for the development and maintenance of healthy lungs. Germline mutations in surfactant-related genes cause a spectrum of severe monogenic pulmonary diseases in patients of all ages. The majority of affected patients present at a very young age, however, a considerable portion of patients have adult-onset disease. Mutations in surfactant-related genes are present in up to 8% of adult patients with familial interstitial lung disease (ILD) and associate with the development of pulmonary fibrosis and lung cancer.High disease penetrance and variable expressivity underscore the potential value of genetic analysis for diagnostic purposes. However, scarce genotype-phenotype correlations and insufficient knowledge of mutation-specific pathogenic processes hamper the development of mutation-specific treatment options.This article describes the genetic origin of surfactant-related lung disease and presents spectra for gene, age, sex and pulmonary phenotype of adult carriers of germline mutations in surfactant-related genes.