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Discolouration of mango lenticels intensifies progressively from a slight red halo during the initial development of the condition, to a blackened area surrounding each lenticel. Initial aqueous methanol extracts of discoloured tissue were further fractionated into phenolic groups and analysed by means of reversed-phase high performance liquid chromatography. Discernable shifts in phenolic profiles correlated with the colour changes in affected lenticels. After staining with Vanillin-HC1, fluorescence microscopy of fixed material revealed the locations of, and changes in the different forms of phenolics associated with various degrees of discolouration. The results confirmed that the compounds responsible for the discolouration of lenticels were simpler flavonones rather than more complex anthocyanidins. The chromatographic results correlated with previous observations using transmission electron microscopy, which indicated that the accumulation of cell wall-bound phenolics did not result from vacuolar collapse or membrane disintegration. [ABSTRACT FROM AUTHOR]

Citrus black spot (CBS) is a fungal disease caused by Phyllosticta citricarpa Kiely, (McAlpine Van der Aa), with most cultivars being susceptible to infection. Currently, disease control is based on the application of protective fungicides, which is restricted due to resistance, health and environmental concerns. Although using natural products for disease management is gaining momentum, more advances are required. This study obtained the metabolic profiles of the essential oil and cuticular waxes of two citrus cultivars with a varying susceptibility to CBS infection using gas chromatography-mass spectrometry. A multivariate data analysis identified possible biomarker compounds that contributed to the difference in susceptibility between the two cultivars. Several identified biomarkers were tested in vitro for their antifungal properties against P. citricarpa . Two biomarkers, propanoic acid and linalool, were able to completely inhibit pathogen growth at 750 mg/L and 2000 mg/L, respectively.

Introduction: The use of chemical fungicides to combat disease has made a substantial contribution to food quality and security. Nonetheless, their applications have been limited due to environmental and health concerns, unaffordability, and the fact that pathogens have acquired resistance to some of these fungicides. Alternative eco-friendly and safe control methods should be explored. The current study investigated the influence of citrus rind phenolic compounds against Phyllosticta citricarpa infection by metabolic profiling of two citrus cultivars with varying degrees of susceptibility to infection., Methods: Chromatographic data obtained by Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC) was subjected to multivariate data analysis to identify biomarkers associated with the tolerant cultivar. The identified biomarkers were tested in vitro against P. citricarpa., Results: Seville oranges, a tolerant cultivar, displayed higher levels of phenolic content and lower total sugar content, that are both associated with lower susceptibility to citrus black spot infection. The generated Principal Component Analysis (PCA) and Orthogonal Projection to Latent Structures-Discriminant Analysis (OPLS-DA) models gave an overview of the data set and identified components that may be responsible for the differences in susceptibility between the two cultivars. Candidate biomarkers associated with tolerance were identified as naringin, neoeriocitrin, bruteiridin, melitidin, and lucenin-2., Conclusion: Naringin, a major candidate biomarker was able to inhibit the growth of the pathogen at 10 000 ppm., (© 2024. The Author(s).)

Concerns associated with the use of synthetic colourants backs the demand for natural colourants. Thus, the current study aimed at characterizing crude fungal pigments produced by Penicillium multicolour, P. canescens, Talaromyces verruculosus, Fusarium solani and P. herquie. This included their antioxidant and antimicrobial properties together with acute toxicity evaluation on zebrafish embryos. The identification of pigment compounds was achieved through MS and IR data. The study demonstrated a substantial radical scavenging activity of extracts ranging from 65.49 to 74.46%, close to that of ascorbic acid (89.21%). Penicillium canescens and F. solani exhibited a strong antimicrobial activity against Escherichia coli and Enterococcus aerogenes and Salmonella typhi, Staphylococcus aureus and Bacillus cereus at MIC values ranging from 1.5 to 2.5 mg/mL. However, some levels of toxicity were observed for all extracts at a concentration range of 3-5 mg/mL. Pigment by P. multicolour, T. verruculosus and F. solani were tentatively identified through IR and MS data as sclerotiorin (yellow), rubropunctamine (red) and bostrycoidin (red). In conclusion, the study demonstrates a market potential of filamentous fungi pigments due to their antioxidant, antimicrobial activities, and prominent colours. Although there are some toxicity concerns, further tests must be done using molecular docking, albino mice and cell linings., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

α-unsaturated esters are fruity-aromatic compounds which are largely spread in the volatilome of many different fruits, but they are rarely found in the volatilome of yeasts. The yeast S. suaveolens has been recently shown to produce relatively high amounts of α-unsaturated esters and it appears to be an interesting model for the production of these compounds. This study aimed to isolate new α-unsaturated ester-producing yeasts by focusing on strains displaying a similar metabolism to S. suaveolens . While the production of α-unsaturated esters by S. suaveolens is believed to be closely related to its ability to grow on media containing branched-chain amino acids (isoleucine, leucine and valine) as the sole carbon source (ILV + phenotype), in this study, an original screening method was developed that selects for yeast strains displaying ILV + phenotypes and is able to produce α-unsaturated esters. Among the 119 yeast strains isolated from the feces of 42 different South African wild animal species, 43 isolates showed the ILV + phenotype, among which 12 strains were able to produce α-unsaturated esters. Two interesting α-unsaturated esters were detected in two freshly isolated strains, both identified as Galactomyces candidus . These new esters were detected neither in the volatilome of the reference strain S. suaveolens , nor in any other yeast species previously studied for their aroma production. This work demonstrated the efficiency of an original method to rapidly screen for α-unsaturated ester-producing yeasts. In addition, it demonstrated that wild animal feces are interesting resources to isolate novel strains producing compounds with original aromas.

Sceletium tortuosum (L.) N.E.Br. (Mesembryanthemaceae), commonly known as kanna or kougoed, is an effective indigenous medicinal plant in South Africa, specifically to the native San and Khoikhoi tribes. Today, the plant has gained strong global attraction and reputation due to its capabilities to promote a sense of well-being by relieving stress with calming effects. Historically, the plant was used by native San hunter-gatherers and Khoi people to quench their thirst, fight fatigue and for healing, social, and spiritual purposes. Various studies have revealed that extracts of the plant have numerous biological properties and isolated alkaloids of Sceletium tortuosum are currently being used as dietary supplements for medicinal purposes and food. Furthermore, current research has focused on the commercialization of the plant because of its treatment in clinical anxiety and depression, psychological and psychiatric disorders, improving mood, promoting relaxation and happiness. In addition, several studies have focused on the isolation and characterization of various beneficial bioactive compounds including alkaloids from the Sceletium tortuosum plant. Sceletium was reviewed more than a decade ago and new evidence has been published since 2008, substantiating an update on this South African botanical asset. Thus, this review provides an extensive overview of the biological and pharmaceutical properties of Sceletium tortuosum as well as the bioactive compounds with an emphasis on antimicrobial, anti-inflammatory, anti-oxidant, antidepressant, anxiolytic, and other significant biological effects. There is a need to critically evaluate the bioactivities and responsible bioactive compounds, which might assist in reinforcing and confirming the significant role of kanna in the promotion of healthy well-being in these stressful times.

Context.—: The burden of chronic kidney disease in Indigenous Australians is 7.3 times higher than that of non-Indigenous Australians. If chronic kidney disease is detected early and managed, deterioration in kidney function can be reduced. Urine albumin to creatinine ratio is a key marker of early renal damage., Objective.—: To report on 16 years of analytic quality of urine albumin to creatinine ratio testing on Siemens DCA devices enrolled in the national Quality Assurance for Aboriginal and Torres Strait Islander Medical Services point-of-care testing program., Design.—: Quality Assurance for Aboriginal and Torres Strait Islander Medical Services participants are required to test 2 quality assurance samples each month across two 6-monthly testing cycles per year. Participants also test 2 quality control samples monthly., Results.—: The percentage of urine albumin, creatinine, and albumin to creatinine ratio results for quality assurance point-of-care testing that were within assigned allowable limits of performance averaged 96.9%, 95.9%, and 97.5%, respectively. The percentage acceptable quality control results for urine albumin and creatinine averaged 93.5% and 86.8%. The median imprecision for urine albumin, creatinine, and albumin to creatinine ratio quality assurance testing averaged 5.5%, 4.1%, and 3.3%, respectively, and the median within-site imprecision for quality control testing averaged 5.4%, 4.3%, and 5.7%, respectively, for the low sample and 4.0%, 4.1%, and 4.5%, respectively, for the high sample., Conclusions.—: For 16 years the DCA system has proven to be reliable and robust and operators at Aboriginal medical services have demonstrated they are able to conduct point-of-care testing for urine albumin to creatinine ratio that consistently meets analytic performance standards., (© 2020 College of American Pathologists.)

Fumonisins are common contaminants of maize. The neutral red assay, using the RTL-W1 trout liver cell line, and the fish embryo test (FET), using zebrafish, were selected to assess the effect of pH on the cytotoxicity, acute toxicity and teratogenicity of fumonisin B 1 (FB 1 ). The results demonstrated that FB 1 exerts low cytotoxicity towards RTL-W1 cells without pH adjustment (IC 50 1 746 μM), and no cytotoxicity after pH-adjustment to physiological conditions. The LC 50 value for FB 1 in the FET (1 058 μM at 48 h) confirmed low acute toxicity. Adjusting the pH to physiological conditions reduced the acute toxicity of FB 1 towards zebrafish embryos, emphasising the importance of acidity/basicity of the medium in toxicity testing. Hydrolysed FB 1 was less toxic than FB 1 (LC 50 2 690 μM at 48 h), and neither were teratogenic towards zebrafish embryos. Results confirm that the FET may account for effects not observable in cell cultures., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Endophytic fungi have the ability to live inside the host plant tissues without causing neither symptoms of diseases/or harm. Opportunistic infections are accountable for majority of the outbreaks, thereby putting a burden on the health system. To investigate and characterize the bioactive compounds for the control of bacteria of clinical importance, extracts from endophytic fungi were isolated from indigenous South African medicinal plants. Extracts from endophytic fungi were isolated from 133 fungal strains and screened against Gram positive and negative bacteria namely Bacillus cereus, Escherichia coli , Enterococcus faecium, and E. gallinarum using disk diffusion. Furthermore, gas chromatography-mass spectrometry was performed to identify the bioactive compounds. Sixteen out of one hundred and thirty-three (12%) fungi extracts exhibited antibacterial properties against some of the selected bacteria. E. coli was found to be the most susceptible in contrast to E. faecium and E. gallinarum which were the most resistant. The isolate MHE 68, identified as Alternaria sp. displayed the greater spectrum of antibacterial activities by controlling selected clinical bacteria strains including resistant E. faecium and E. gallinarum . The chemical analysis of the extract from MHE 68 indicated that linoleic acid (9,12-octadecadienoic acid (Z,Z)) and cyclodecasiloxane could be accountable for the antibacterial activity. This is the first study conducted on the secondary metabolites produced by endophytic fungal strains isolated from the Pelargonium sidoides DC. possessing antibacterial properties., (© 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the Korean Society of Mycology.)

Diaporthe species cause Phomopsis cane and leaf spot as well as Phomopsis dieback on grapevines. Symptoms of Phomopsis dieback have increasingly been observed over the past few years. In order to assess the current status of Diaporthe on grapevines in the Western Cape Province of South Africa, isolations were made from dormant grafted nursery vines, dormant rootstock canes, and dying or dead spurs of field vines. Cultures identified as Diaporthe based on morphological features were further identified to species level by sequencing the internal transcribed spacers (ITS) 1 and 2 and 5.8S rRNA and, for a representative subsample of isolates, the partial beta-tubulin ( tub2 ) and translation elongation factor 1-alpha (EF1-α) genes. Phylogenetic analysis of the combined ITS, tub2 , and EF1-α data revealed nine Diaporthe species associated with grapevines during this survey. One of these represents a new species, D. nebulae sp. nov., and three other species, namely D. novem , D. cynaroidis , and D. serafiniae , are reported on grapevines in South Africa for the first time. Species-specific primers were designed for PCR identification of D. ampelina , D. ambigua , and D. foeniculina . Pathogenicity studies conducted on detached grapevine shoots indicated D. ampelina , D. novem , and D. nebulae sp. nov. as the most virulent species.

Autochthonous bioaugmentation, by exploiting the indigenous microorganisms of the contaminated environment to be treated, can represent a successful bioremediation strategy. In this perspective, we have assessed by molecular methods the evolution of bacterial and fungal communities during the selective enrichment on different pollutants of a soil strongly polluted by mixtures of aliphatic and polycyclic hydrocarbons. Three consecutive enrichments were carried out on soil samples from different soil depths (0-1, 1-2, 2-3 m), and analyzed at each step by means of high-throughput sequencing of bacterial and fungal amplicons biomarkers. At the end of the enrichments, bacterial and fungal contaminants degrading strains were isolated and identified in order to (i) compare the composition of enriched communities by culture-dependent and culture-independent molecular methods and to (ii) obtain a collection of hydrocarbon degrading microorganisms potentially exploitable for soil bioremediation. Molecular results highlighted that for both bacteria and fungi the pollutant had a partial shaping effect on the enriched communities, with paraffin creating distinct enriched bacterial community from oil, and polycyclic aromatic hydrocarbons generally overlapping; interestingly neither the soil depth or the enrichment step had significant effects on the composition of the final enriched communities. Molecular analyses well-agreed with culture-dependent analyses in terms of most abundant microbial genera. A total of 95 bacterial and 94 fungal strains were isolated after selective enrichment procedure on different pollutants. On the whole, isolated bacteria where manly ascribed to Pseudomonas genus followed by Sphingobacterium , Bacillus , Stenothrophomonas , Achromobacter , and Serratia . As for fungi, Fusarium was the most abundant genus followed by Trichoderma and Aspergillus . The species comprising more isolates, such as Pseudomonas putida , Achromobacter xylosoxidans and Ochromobactrum anthropi for bacteria, Fusarium oxysporum and Fusarium solani for fungi, were also the dominant OTUs assessed in Illumina.

Intraspecific diversity promotes evolutionary change, and when partitioned among geographic regions or habitats can form the basis for speciation. Marine species live in an environment that can provide as much scope for diversification in the vertical as in the horizontal dimension. Understanding the relevant mechanisms will contribute significantly to our understanding of eco-evolutionary processes and effective biodiversity conservation. Here, we provide an annotated genome assembly for the deep-sea fish Coryphaenoides rupestris and re-sequencing data to show that differentiation at non-synonymous sites in functional loci distinguishes individuals living at different depths, independent of horizontal spatial distance. Our data indicate disruptive selection at these loci; however, we find no clear evidence for differentiation at neutral loci that may indicate assortative mating. We propose that individuals with distinct genotypes at relevant loci segregate by depth as they mature (supported by survey data), which may be associated with ecotype differentiation linked to distinct phenotypic requirements at different depths.