The endophytic fungus Epicoccum nigrum was isolated from sugarcane and the bioguided fractionation of the ethyl acetate extract led to the isolation of epicolactone, mellein, and 4,5‐dimethylresorcinol. Characterization of epicolactone by MS, NMR and X‐ray crystallography revealed a new natural product with an unusual carbon skeleton. The production of this secondary metabolite decreased in mutants of Epicoccum nigrum transformed by Agrobacterium tumefaciens. Additionally, these mutants produced 4‐hydroxymellein.
Species of genus Burkholderia display different interaction profiles in the environment, causing either several diseases in plants and animals or being beneficial to some plants, promoting their growth, and suppressing phytopathogens. Burkholderia spp. also produce many types of biomolecules with antimicrobial activity, which may be commercially used to protect crops of economic interest, mainly against fungal diseases. Herein we have applied matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to investigate secondary metabolites produced by B. seminalis TC3.4.2R3 in monoculture and coculture with plant pathogen Fusarium oxysporum. The siderophore pyochelin and the rhamnolipid Rha-Rha-C15-C14 were detected in wild-type B. seminalis strain, and their productions were found to vary in mutant strains carrying disruptions in gene clusters associated with antimicrobial compounds. Two mycotoxins were detected in F. oxysporum. During coculture with B. seminalis, metabolites probably related to defense mechanisms of these microorganisms were observed in the interspecies interaction zone. Our findings demonstrate the effective application of MALDI-MSI in the detection of bioactive molecules involved in the defense mechanism of B. seminalis, and these findings suggest the potential use of this bacterium in the biocontrol of plant diseases caused by F. oxysporum. Graphical Abstract ᅟ.
This work describes the production of biodiesel from Jatropha curcas oil. The kernel samples provided by Embrapa-PI, were first crushed in a blender and then subjected to extraction with hexane. The oil yield was between 54.71 ± 0.47 and 64.16 ± 2.88%. The J. curcas oil was then submitted to two different kinds of degumming, first with water and second with H 3 PO 4 to evaluate the influence of these processes in the yield of the transesterification reaction. Methyl and ethyl biodiesel prepared from the degummed oil with H 3 PO 4 had higher conversions than those prepared with the degummed with water. Therefore, among the processes of degumming studied, H 3 PO 4 was more suitable for the treatment of J. curcas oil. The study shows the results about oxidation stability were good, because the biodiesels methyl and ethyl biodiesel have induction period at 13.51 h and 13.03 h without antioxidant addition when submitted a Rancimat text. Such biodiesels had their physicochemical parameters defined under the specifications of ANP Resolutions n 14/2012 (ANP-National Agency of Petroleum, Natural Gas and Biofuels from Brazil). The results showed that J. curcas cultivation in Brazil is an adequate source for biodiesel production, considering the technical standards available.
In this study, we describe the characterization of the peptide profile in commercial Prato cheese by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) and capillary electrophoresis (CE). Ten commercial Prato cheese brands were characterized via their physicochemical composition and subjected to fractionation according to solubility at pH 4.6. The pH 4.6 insoluble fraction was evaluated by CE, whereas MALDI-MS was applied to the fraction soluble at pH 4.6 and in 70% ethanol. CE revealed a characteristic pattern of hydrolysis, with formation of para-κ-casein, hydrolysis of α -casein at the Phe - Phe bond, and hydrolysis of β-casein. For the MALDI-MS data, a complex peptide profile was observed, with the identification of 44 peptides previously reported (24 peptides from α -casein, 14 from β-casein, 3 from κ-casein, and 3 from α -casein). It was also observed that cheeses with salt-in-moisture content greater than 5% showed an accumulation of a bitter-tasting peptide (m/z 1536, α -CN f1-13), suggesting a relationship between the higher salt concentration and the abundance of this peptide. In conclusion, the results showed that even commercial cheeses produced with different raw material and processing conditions showed very similar peptide profiles when assessed at the molecular level, and only 9 peptides were responsible for discrimination of cheeses.
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