Biocontrol of Phyllosticta citricarpa by Bacillus spp.: biological and chemical aspects of the microbial interaction.

Citrus fruits are the most produced fruits in the world, but they are threatened by several pathogens, including the fungus Phyllosticta citricarpa, the causal agent of citrus black spot (CBS). The fungus affects most citrus species and the infection results in economic losses in citrus-producing areas. This disease causes the aesthetic depreciation of fresh fruit, impairing its commercialization. As an alternative to the use of synthetic fungicides to control the pathogen, the biological control, using bacteria of the genus Bacillus, is highlighted. Such microorganisms enable biocontrol by the production of volatile organic compounds (VOC) or non-volatile. Therefore, this work aimed to evaluate the production of VOC by isolates of Bacillus spp. grown in different culture media; to evaluate the effects of these compounds on the evolution of CBS lesions in orange fruits; to study the effects of VOC on resistance induction in orange fruits; to evaluate the effects of VOC on P. citricarpa morphology in CBS lesions, and to identify the produced VOC. Tryptone soya agar (TSA) and tryptone soya broth (TSB) media used to culture the bacterium resulted in up to 73% pathogen inhibition by VOC. Volatile compounds from Bacillus spp. ACB-65 and Bacillus spp. ACB-73 when cultured in TSB culture medium provided 86% inhibition of freckles that evolved to hard spots. The volatile fractions produced by the bacteria were identified as alcohols, ketones, amines, ethers, aldehydes and carboxylic acids that can serve as arsenal against the phytopathogen. The present work demonstrated the potential of VOC produced by Bacillus spp. in the control of P. citricarpa.

Forensic Investigations of Diesel Oil Spills in the Environment Using Comprehensive Two-Dimensional Gas Chromatography-High Resolution Mass Spectrometry and Chemometrics: New Perspectives in the Absence of Recalcitrant Biomarkers.

Forensic investigations of oil spills aim to find the responsible source(s) of the spill. Oil weathering processes change the chemical composition of the spilled oil and make the matching of oil spill samples to potential sources difficult. Diesel oil spill cases are more challenging, because biomarkers recalcitrant to long-term weathering are absent. We developed and tested a new method for the analysis and matching of diesel oil spills using two-dimensional gas chromatography-high resolution mass spectrometry (GC × GC - HRMS) and 2D-CHEMSIC (2-Dimensional CHEMometric analysis of Selected Ion Chromatograms), an extension of the CHEMSIC method to GC × GC data. The 2D-CHEMSIC performs pixel-based analysis using chemometrics on concatenated sections of 2D extracted ion chromatograms to assess the overall chemical variability of the samples, with potential applications for matching spill-source pairs in forensic investigations. The method was tested on samples from a number of diesel oil spill cases, (i) distinguishing chemically similar source diesels, (ii) investigating weathering effects on spill samples to determine type and degree of weathering, and (iii) improving the matching of diesel oil spills affected by weathering. Positive matches for spill-source pairs were identified after excluding the signals from the hydrocarbons most susceptible to evaporation, and photo-oxidized spills were also matched due to the presence of unaffected hydrocarbons. Forensic diagnostics obtained by the 2D-CHEMSIC were validated by the conventional CEN-Tr method.

Fructooligosaccharide intake promotes epigenetic changes in the intestinal mucosa in growing and ageing rats.

PURPOSE: The aim of this study was to investigate the relationship between fructooligosaccharide (FOS) intake at different life stages of Wistar rats and its stimulatory effects on intestinal parameters. METHODS: Recently weaned and ageing female rats were divided into growing and ageing treatments, which were fed diets that partially replaced sucrose with FOS for 12 weeks. RESULTS: Dietary FOS intake induced a significant increase in the numbers of Bifidobacterium and Lactobacillus in growing rats. FOS intake was associated with increased butyric acid levels and a reduced pH of the caecal contents at both ages. Differential gene expression patterns were observed by microarray analysis of growing and ageing animals fed the FOS diet. A total of 133 genes showed detectable changes in expression in the growing rats, while there were only 19 gene expression changes in ageing rats fed with FOS. CONCLUSION: These results suggest that dietary FOS intake may be beneficial for some parameters of intestinal health in growing rats.

Simple, Expendable, 3D-Printed Microfluidic Systems for Sample Preparation of Petroleum.

In this study, we introduce a simple protocol to manufacture disposable, 3D-printed microfluidic systems for sample preparation of petroleum. This platform is produced with a consumer-grade 3D-printer, using fused deposition modeling. Successful incorporation of solid-phase extraction (SPE) to microchip was ensured by facile 3D element integration using proposed approach. This 3D-printed µSPE device was applied to challenging matrices in oil and gas industry, such as crude oil and oil-brine emulsions. Case studies investigated important limitations of nonsilicon and nonglass microchips, namely, resistance to nonpolar solvents and conservation of sample integrity. Microfluidic features remained fully functional even after prolonged exposure to nonpolar solvents (20 min). Also, 3D-printed µSPE devices enabled fast emulsion breaking and solvent deasphalting of petroleum, yielding high recovery values (98%) without compromising maltene integrity. Such finding was ascertained by high-resolution molecular analyses using comprehensive two-dimensional gas chromatography and gas chromatography/mass spectrometry by monitoring important biomarker classes, such as C10 demethylated terpanes, ααα-steranes, and monoaromatic steroids. 3D-Printed chips enabled faster and reliable preparation of maltenes by exhibiting a 10-fold reduction in sample processing time, compared to the reference method. Furthermore, polar (oxygen-, nitrogen-, and sulfur-containing) analytes found in low-concentrations were analyzed by Fourier transform ion cyclotron resonance mass spectrometry. Analysis results demonstrated that accurate characterization may be accomplished for most classes of polar compounds, except for asphaltenes, which exhibited lower recoveries (82%) due to irreversible adsorption to sorbent phase. Therefore, 3D-printing is a compelling alternative to existing microfabrication solutions, as robust devices were easy to prepare and operate.

Characterization of crude oil biomarkers using comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry.

Oil samples from Recôncavo basin (NE Brazil), previously analyzed by traditional techniques such as gas chromatography coupled to tandem mass spectrometry, were evaluated using comprehensive two-dimensional gas chromatography coupled to quadrupole mass spectrometry and comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry along with simplified methods of samples preparation to evaluate the differences and advantages of these analytical techniques to better understand the development of the organic matter in this basin without altering the normal distribution of the compounds in the samples. As a result, the geochemical parameters calculated by comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry described better the origin, maturity, and biodegradation of both samples probably by increased selectivity, resolution, and sensitivity inherent of the multidimensional technique. Additionally, the detection of the compounds such as, the C(14α-) homo-26-nor-17α-hopane series, diamoretanes, nor-spergulanes, C19 -C26 A-nor-steranes and 4α-methylsteranes resolved and detected by comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry were key to classify and differentiate these lacustrine samples according to their maturity and deposition conditions.

In vivo determination of the volatile metabolites of saprotroph fungi by comprehensive two-dimensional gas chromatography.

In this work, we discuss the use of multiway principal component analysis combined with comprehensive two-dimensional gas chromatography to study the volatile metabolites of the saprophytic fungus Memnoniella sp. isolated in vivo by headspace solid-phase microextraction. This fungus has been identified as having the ability to induce plant resistance against pathogens, possibly through its volatile metabolites. Adequate culture media were inoculated, and its headspace was then sampled with a solid-phase microextraction fiber and chromatographed every 24 h over seven days. The raw chromatogram processing using multiway principal component analysis allowed the determination of the inoculation period, during which the concentration of volatile metabolites was maximized, as well as the discrimination of the appropriate peaks from the complex culture media background. Several volatile metabolites not previously described in the literature on biocontrol fungi were observed, as well as sesquiterpenes and aliphatic alcohols. These results stress that, due to the complexity of multidimensional chromatographic data, multivariate tools might be mandatory even for apparently trivial tasks, such as the determination of the temporal profile of metabolite production and extinction. However, when compared with conventional gas chromatography, the complex data processing yields a considerable improvement in the information obtained from the samples.

Tuning the selectivity of ionic liquid stationary phases for enhanced separation of nonpolar analytes in kerosene using multidimensional gas chromatography.

In this study, a series of ionic liquids (ILs) are evaluated as stationary phases in comprehensive two-dimensional gas chromatography (GC × GC) for the separation of aliphatic hydrocarbons from kerosene. IL-based stationary phases were carefully designed to evaluate the role of cavity formation/dispersive interaction on the chromatographic retention of nonpolar analytes by GC × GC. The maximum allowable operating temperature (MAOT) of the IL-based columns was compared to that of commercial IL-based columns. Evaluation of the solvation characteristics of GC columns guided the selection of the best performing IL-based stationary phases for the resolution of aliphatic hydrocarbons, namely, trihexyl(tetradecyl)phosphonium tetrachloroferrate ([P66614][FeCl4]) and trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)trifluorophosphate ([P66614][FAP]) ILs. The best performing [P66614][FeCl4] IL-based column exhibited a MAOT of 320 °C, higher than the commercial SUPELCOWAX 10 (MAOT of 280 °C) and commercial IL-based columns (MAOT up to 300 °C). The structurally tuned [P66614][FeCl4] IL stationary phase exhibited improved separation of aliphatic hydrocarbons by GC × GC compared to the commercial columns examined (e.g., OV-1701, SUPELCOWAX 10, SLB-IL60, SLB-IL100, and SLB-IL111).

Surgery is associated with better long-term outcomes than pharmacological treatment for obesity: a systematic review and meta-analysis.

Obesity is a highly prevalent disease with numerous complications. Both intensive medical treatment with the use of pharmacological drugs and bariatric surgery are current options. The objective of this meta-analysis was to compare, in the long-term, intensive medical treatment and surgery based on twelve parameters related to weight loss, cardiovascular and endocrine changes. A review of the literature was conducted in accordance with the PRISMA guidelines (PROSPERO: CRD42021265637). The literature screening was done from inception to October 2023 through PubMed, EMBASE and Web of Science databases. We included randomized clinical trials that had separate groups for medical treatment and bariatric surgery as an intervention for obesity. The risk of bias was assessed through RoB2. A meta-analysis was performed with measures of heterogeneity and publication bias. Subgroup analysis for each surgery type was performed. Data is presented as forest-plots. Reviewers independently identified 6719 articles and 6 papers with a total 427 patients were included. All studies were randomized controlled trials, three had a follow up of 5 years and two had a follow up of 10 years. Both groups demonstrated statistical significance for most parameters studied. Surgery was superior for weight loss (- 22.05 kg [- 28.86; - 15.23), total cholesterol (- 0.88 [- 1.59; - 0.17]), triglycerides (- 0.70 [- 0.82; - 0.59]), HDL (0.12 [0.02; 0.23]), systolic pressure (- 4.49 [- 7.65; - 1.33]), diastolic pressure (- 2.28 [- 4.25; - 0.31]), Hb glycated (- 0.97 [- 1.31; - 0.62]), HOMA IR (- 2.94; [- 3.52; - 2.35]) and cardiovascular risk (- 0.08; [- 0.10; - 0.05]). Patient in the surgical treatment group had better long term outcomes when compared to the non-surgical group for most clinical parameters.

Determination of Se using a solid-phase micro-extraction device coupled to a graphite furnace and detection by gas chromatography-mass spectrometry.

A solid-phase micro-extraction (SPME) method using an SPME fiber device and graphite furnace (GF) for extracting Se compounds was proposed. Various factors affecting the derivatization and extraction of Se(IV) by SPME-GF were evaluated, including the effect of acid (type and concentration), the concentration of the derivatizing agent, the derivatization temperature, the extraction and derivatization times and the extraction temperature. After optimizing these conditions, the quantification of Se(IV) was performed by Gas Chromatography-Mass Spectrometry (GC-MS). The limit of detection was 0.37 µg L(-1) for Se(IV). The method was successfully applied to the total Se determination in certified reference materials (BCR-414 and SRM 1643e). A recovery of 97% was obtained for water (SRM 1643e). After microwave oven decomposition and the reduction of selenium using a mixture of 2 mol L(-1) HCl and 1% (w/v) KBr, a recovery of 101% and a relative standard deviation of 3.5% were attained for plankton (BCR-414). The SPME-GF method combined with GC-MS was also applied to the determination of the total selenium in a drug sample (selenium chelate).

Solid-phase microextraction combined with comprehensive two-dimensional gas chromatography for fatty acid profiling of cell wall phospholipids.

The combination of solid-phase microextraction (SPME) with comprehensive two-dimensional gas chromatography is evaluated here for fatty acid (FA) profiling of the glycerophospholipid fraction from human buccal mucosal cells. A base-catalyzed derivatization reaction selective for polar lipids such as glycerophospholipid was adopted. SPME is compared to a miniaturized liquid-liquid extraction procedure for the isolation of FA methyl esters produced in the derivatization step. The limits of detection and limits of quantitation were calculated for each sample preparation method. Because of its lower values of limits of detection and quantitation, SPME was adopted. The extracted analytes were separated, detected, and quantified by comprehensive two-dimensional gas chromatography with flame ionization detection (FID). The combination of SPME and comprehensive two-dimensional gas chromatography with FID, using a selective derivatization reaction in the preliminary steps, proved to be a simple and fast procedure for FA profiling, and was successfully applied to the analysis of adult human buccal mucosal cells.

MICRObiota on BILIOpancreatic malignant diseases [MICROBILIO]: A systematic review.

INTRODUCTION: The increase in the incidence of pancreatic and biliary cancers has attracted the search for methods of early detection of diseases and biomarkers. The authors propose to analyze new findings on the association between microbiota and Pancreatic Ductal Adenocarcinoma (PDAC) or Cholangiocarcinoma (CCA). METHODS: This systematic review was carried out according to the items of Preferred Reports for Systematic Reviews and Protocol Meta-Analysis (PRISMA-P). This study was registered by the Prospective Register of Systematic Reviews (PROSPERO), identification code CRD42020192748 before the review was carried out. Articles were selected from the PUBMED, EMBASE, and Cochrane databases. RESULTS: Most studies (86.67%) used 16s rRNA as a sequencing method. The main comorbidities found were diabetes mellitus, systemic arterial hypertension, and dyslipidemia. Many studies were limited by the small number of participants, but the biases were mostly low. There was very little concordance about the composition of the microbiome of different sites, for both case and control groups when compared to other studies' results. Bile sample analysis was the one with a greater agreement between studies, as three out of four studies found Escherichia in cases of CCA. CONCLUSION: There was great disagreement in the characterization of both the microbiota of cases and control groups. Studies are still scarce, making it difficult to adequately assess the data in this regard. It was not possible to specify any marker or to associate any genus of microbiota bacteria with PDAC or CCA.

Identification of volatiles from pineapple (Ananas comosus L.) pulp by comprehensive two-dimensional gas chromatography and gas chromatography/mass spectrometry.

Combining qualitative data from the chromatographic structure of 2-D gas chromatography with flame ionization detection (GC×GC-FID) and that from gas chromatography-mass spectrometry (GC/MS) should result in a more accurate assignment of the peak identities than the simple analysis by GC/MS, where coelution of analytes is unavoidable in highly complex samples (rendering spectra unsuitable for qualitative purposes) or for compounds in very low concentrations. Using data from GC×GC-FID combined with GC/MS can reveal coelutions that were not detected by mass spectra deconvolution software. In addition, some compounds can be identified according to the structure of the GC×GC-FID chromatogram. In this article, the volatile fractions of fresh and dehydrated pineapple pulp were evaluated. The extraction of the volatiles was performed by dynamic headspace extraction coupled to solid-phase microextraction (DHS-SPME), a technique appropriate for slurries or solid matrices. Extracted analytes were then analyzed by GC×GC-FID and GC/MS. The results obtained using both techniques were combined to improve compound identifications.

Effects of preparation conditions on the characteristics of poly(lactide-co-glycolide) nanospheres loaded with chloro(5,10,15,20-tetraphenylporphyrinato)indium(III).

A 2(4-1) fractional factorial design was utilized to evaluate the influence of four preparation conditions on six characteristics of poly(lactide-co-glycolide) nanospheres loaded with chloro(5,10,15,20-tetraphenylporphyrinato)indium(III). Ethanol in the aqueous phase and the stirring rate were the factors that most influenced the nanosphere characteristics. An increase in these factors caused a decrease in nanosphere size, recovery yield and residual chloroform and an increase in the percent of residual poly(vinyl alcohol). The synergic interaction between these two factors caused an increase in the percent residual chloroform. The entrapment efficiency was increased by an increase of ethanol in the aqueous phase or an increase in the percent poly(vinyl alcohol), but an overall decrease was obtained due to a synergic interaction between these factors. The stirring rate was the only parameter that caused an increase of the zeta potential. Evolutionary operations were then carried out based on the results from the fractional factorial design and nanospheres were obtained with sizes smaller than 200 nm.

Feeding the family at the end-of-life: An ethnographic study on the role of food and eating practices for families facing death in Portugal.

Little has been said about the disruptive impact that the inability to eat and to participate in mealtimes has for patients with a life-threatening illness and their families. The aim of the current study is to overcome this gap and shed light on how food and eating practices are experienced by families at the end-of-life. An ethnographic research was developed in two Portuguese palliative care units: participant observation was conducted during 10 months and in-depth interviews were carried out with 10 patients with a life-threatening illness, 20 family members and 20 palliative care professionals. Food is not only a matter of nutrition in a biological sense, but also an act of giving care to patients with a life-threatening illness. The findings suggest that food and eating practices affect the processes of relationality and of doing family at the end-of-life in Portugal. Attention is particularly paid to gender differences. The study supports recent sociological research which understands the dying process as a relational experience and intends to develop sociological knowledge on the materialities of care.

Mapping Aspergillus niger Metabolite Biomarkers for In Situ and Early Evaluation of Table Grapes Contamination.

The Aspergillus niger exometabolome was recently investigated using advanced gas chromatography in tandem with multivariate analysis, which allowed a metabolite biomarker pattern to be proposed. Microbial metabolomics patterns have gained enormous relevance, mainly due to the amount of information made available, which may be useful in countless processes. One of the great challenges in microbial metabolomics is related to applications in more complex systems of metabolomics information obtained from studies carried out in culture media, as complications may occur due to the dynamic nature of biological systems. Thus, the main objective of this research was to evaluate the applicability of the A. niger metabololite biomarkers pattern for in situ and early evaluation of table grapes contamination, used as study model. A. niger is a ubiquitous fungus responsible for food contamination, being reported as one of the main agents of the black mold disease, a serious post-harvest pathology of table grapes. This work included analysis from 1 day of growth time of pure A. niger cultures, A. niger cultures obtained from previously contaminated grapes, and finally, an in situ solid-phase microextraction (SPME) approach directly on previously contaminated table grapes. Supervised multivariate analysis was performed which revealed that after 1 day of inoculation it was possible to detect A. niger biomarkers, which can be extremely useful in making this type of method possible for the rapid detection of food contamination. The results obtained confirm the potential applicability of the pattern of A. niger biomarkers for early detection of the fungi (after 1 day of contamination), and may be further explored for access food susceptibility to fungi contamination, based on direct analysis of the food item.

Molecularly imprinted silica as a selective SPE sorbent for triazine herbicides.

A molecularly imprinted organically modified silica was prepared through a simple sol-gel procedure and evaluated as a specific sorbent for SPE of triazine herbicides. The material proved to be highly selective for the template molecule, atrazine, as well as for other structurally related species such as simazine and propazine. The performance of this material was shown to be comparable with commercial acrylate-based molecularly imprinted polymers. The molecularly imprinted silica was applied for the determination of trace levels of the target triazine analytes in sugar cane juice (locally called "garapa").

Corrigendum to "Opportunities for green microextractions in comprehensive two-dimensional gas chromatography / mass spectrometry-based metabolomics - A review" [Analytica Chimica Acta 1040 2018 1-18].

The purpose of this corrigendum is to present the correct silyl-acceptor reactivity order.

Investigating weathering in light diesel oils using comprehensive two-dimensional gas chromatography-High resolution mass spectrometry and pixel-based analysis: Possibilities and limitations.

Petroleum-derived fuels are chronically spilled in urbanized areas, affecting the environment and the population's health. Forensic investigations of oil spills aim to find the responsible source of the spills. Weathering processes (dissolution, evaporation, photo-oxidation and biodegradation) change the chemical composition of the spills and hamper the matching of spill-source pairs, especially for light diesel oils (i.e. n-C9 - n-C20) in which the source diesels can be very similar due to the refining process and only compounds resistant to short- or middle-term weathering are present. In this study, comprehensive two-dimensional gas chromatography - high resolution mass spectrometry (GC × GC - HRMS) and pixel-based analysis were combined for: i) improve the identification of very similar diesel oils, and ii) identify weathering-resistant compounds that can also distinguish samples from different sources. Diesel oils from two sources that have been exposed to different degrees of evaporation, photo-oxidation and biodegradation in a laboratory setup. The study revealed the tentatively identified octanoic acid methyl ester and n-nonaldehyde were more resistance to evaporation than hydrocarbons < n-C15. Furthermore, the hydrocarbons > n-C17 could be used for source-apportionment of all the diesel oils susceptible to evaporation and photo-oxidation, but only pristane and phytane were also more resistant to biodegradation. Naphthenes, bicyclic sesquiterpanes and adamantanes were more resistant to only photo-oxidation and biodegradation. GC × GC - HRMS enhanced the separation of the highly similar naphthenes in the diesel oils; however, the diagnostic power for forensic spill investigations was still similar to 1D GC - HRMS.

Biological Control of Citrus Postharvest Phytopathogens.

Citrus are vulnerable to the postharvest decay caused by Penicillium digitatum, Penicillium italicum, and Geotrichum citri-aurantii, which are responsible for the green mold, blue mold, and sour rot post-harvest disease, respectively. The widespread economic losses in citriculture caused by these phytopathogens are minimized with the use of synthetic fungicides such as imazalil, thiabendazole, pyrimethanil, and fludioxonil, which are mainly employed as control agents and may have harmful effects on human health and environment. To date, numerous non-chemical postharvest treatments have been investigated for the control of these pathogens. Several studies demonstrated that biological control using microbial antagonists and natural products can be effective in controlling postharvest diseases in citrus, as well as the most used commercial fungicides. Therefore, microbial agents represent a considerably safer and low toxicity alternative to synthetic fungicides. In the present review, these biological control strategies as alternative to the chemical fungicides are summarized here and new challenges regarding the development of shelf-stable formulated biocontrol products are also discussed.

Identification of gasoline adulteration using comprehensive two-dimensional gas chromatography combined to multivariate data processing.

A method to detect potential adulteration of commercial gasoline (Type C gasoline, available in Brazil and containing 25% (v/v) ethanol) is presented here. Comprehensive two-dimensional gas chromatography with flame ionization detection (GCxGC-FID) data and multivariate calibration (multi-way partial least squares regression, N-PLS) were combined to obtain regression models correlating the concentration of gasoline on samples from chromatographic data. Blends of gasoline and white spirit, kerosene and paint thinner (adopted as model adulterants) were used for calibration; the regression models were evaluated using samples of Type C gasoline spiked with these solvents, as well as with ethanol. The method was also checked with real samples collected from gas stations and analyzed using the official method. The root mean square error of prediction (RMSEP) for gasoline concentrations on test samples calculated using the regression model ranged from 3.3% (v/v) to 8.2% (v/v), depending on the composition of the blends; in addition, the results for the real samples agree with the official method. These observations suggest that GCxGC-FID and N-PLS can be an alternative for routine monitoring of fuel adulteration, as well as to solve several other similar analytical problems where mixtures should be detected and quantified as single species in complex samples.