Enrichment, isolation and characterisation of ruminal bacteria that degrade non-protein amino acids from the tropical legume Acacia angustissima

Acacia angustissima has been proposed as a protein supplement in countries where low quality forages predominate. A number of non-protein amino acids have been identified in the leaves of A. angustissima and these have been linked to toxicity in ruminants. The non-protein amino acid 4-n-acetyl-2,4-diaminobutyric acid (ADAB) has been shown to be the major amino acid in the leaves of A. angustissima. The current study aimed to identify micro-organisms from the rumen environment capable of degrading ADAB by using a defined rumen-simulating media with an amino acid extract from A. angustissima. A mixed enrichment culture was obtained that exhibited substantial ADAB-degrading ability. Attempts to isolate an ADAB-degrading micro-organism were carried out, however no isolates were able to degrade ADAB in pure culture. This enrichment culture was also able to degrade the non-protein amino acids diaminobutyric acid (DABA) and diaminopropionic acid (DAPA) which have structural similarities to ADAB. Two isolates were obtained which could degrade DAPA. One isolate is a novel Grain-positive rod (strain LPLR3) which belongs to the Firmicutes and is not closely related to any previously isolated bacterium. The other isolate is strain LPSR1 which belongs to the Gammaproteobacteria and is closely related (99.93% similar) to Klebsiella pneumoniae subsp. ozaenae. The studies demonstrate that the rumen is a potential rich source of undiscovered micro-organisms which have novel capacities to degrade plant secondary compounds. (c) 2005 Elsevier B.V. All rights reserved.

The ethnopharmacology of plants used as both food and medicine in a Totonac community of Mexico

Most ethnopharmacological studies overlook food plants, yet many edible plants, also have medicinal value. I documented plants that are used as both food and medicine by the Totonac of Zapotitlan de Mendez, Mexico and recorded the presence of selected secondary compounds, and physical characteristics in these plants. Photoactivity, antimicrobial, and antifungal assays also were performed. The presence of these properties were compared among food/medicine plants, food, medicinal, and randomly selected plants. I predicted that a higher percentage of medicinal plants would contain the secondary compounds, physical characteristics, and bioactivity compared to the other groups. Phenolics and cyanogenic glycosides in the medicinal group were significantly greater than in the food/medicine group. The food plants did not differ greatly from the medicinal plants. This research indicates that including food plants in ethnomedical studies could provide a more complete knowledge of peoples therapeutic resources and practices. ^

Non-thermal Plasma Exposure Rapidly Attenuates Bacterial AHL-Dependent Quorum Sensing and Virulence.

The antimicrobial activity of atmospheric pressure non-thermal plasma has been exhaustively characterised, however elucidation of the interactions between biomolecules produced and utilised by bacteria and short plasma exposures are required for optimisation and clinical translation of cold plasma technology. This study characterizes the effects of non-thermal plasma exposure on acyl homoserine lactone (AHL)-dependent quorum sensing (QS). Plasma exposure of AHLs reduced the ability of such molecules to elicit a QS response in bacterial reporter strains in a dose-dependent manner. Short exposures (30-60 s) produce of a series of secondary compounds capable of eliciting a QS response, followed by the complete loss of AHL-dependent signalling following longer exposures. UPLC-MS analysis confirmed the time-dependent degradation of AHL molecules and their conversion into a series of by-products. FT-IR analysis of plasma-exposed AHLs highlighted the appearance of an OH group. In vivo assessment of the exposure of AHLs to plasma was examined using a standard in vivo model. Lettuce leaves injected with the rhlI/lasI mutant PAO-MW1 alongside plasma treated N-butyryl-homoserine lactone and n-(3-oxo-dodecanoyl)-homoserine lactone, exhibited marked attenuation of virulence. This study highlights the capacity of atmospheric pressure non-thermal plasma to modify and degrade AHL autoinducers thereby attenuating QS-dependent virulence in P. aeruginosa.

Crescimento e desenvolvimento de Plinia cauliflora de acordo com a intensidade luminosa em clima subtropical

The jabuticaba fruit tree from classified in the Myrtaceae family and Plinia genre. There are about nine species of this fruit tree, that include as most important, Plinia trunciflora (jabuticaba de cabinho), naturally occurring in southwestern Paraná State, Brazil, P. cauliflora (jabuticaba Paulista or Jabuticaba Açu) and P. jaboticaba (Vell) (jabuticaba sabará), with all the over species producing fruit for the industry or fresh consumption. Nevertheless, there aren‟t commercial orchards with this culture, with highest yield part from extractive. This fact can be combined with lack of technical knowledge for the plants produce in the field. As these species are found in the forest, the first point is whether they can adapt to other light intensity conditions. The aim of this work was to identify the adaptive behavior of jabuticaba fruit seedling and tree when they were put in different light intensities and what this can be considered ideal for the growth, as well as, its influence in the leaves secondary compounds production. Two experiments were conducted, with the first involved with the study of the seedlings and the second with plants in the field. The work was carried out at Universidade Tecnológica Federal do Paraná – Câmpus Dois Vizinhos, Paraná State - Brazil. The experimental design was a completely randomized and a block design with four treatments and four replications of 10 seedlings or two plants per plot, according to nursery or orchard conditions, respectively. The treatments were base according to the light intensity. The treatments used were, 1 - full sun, similar the orchard condition, with 0% shading; 2 - side cover with shade cloth and top with transparent plastic, representing a gap forest condition; 3 - side and top cover with shade cloth, representing stage where the forest canopy is closing, focusing only indirect sunlight; 4 - side and top cover with shade cloth, simulating a closed canopy condition, with PPD (photon flux density) of 10% (90% shading); 5 - side and top cover with shade cloth, simulating a more open canopy condition with PPD 65% (35% shading). The growth and development seedling and plant characteristics were evaluated once by month, as also, during time part in the plants the secondary metabolites leaves, soil activity microbiological and the fresh and dry matter root and shoot and, root length from seedlings. For the growth and development of jabuticaba Açú Paulista seedling recommend to use of side cover with shade cloth and top with transparent plastic, representing a gap forest condition. In orchard, for the growth and development of plants jabuticaba Híbrida tree it was recommended the use of side and top cover with shade cloth of some type. For production of secondary metabolites of leaves, the plant must to be full sunlight condition orchard.

Performance of Sirex noctilio’s biocontrol agent Deladenus siricidicola, in known and predicted hosts

Survival of the free-living mycetophagous form of Deladenus siricidicola, the major biological control agent of Sirex woodwasp, Sirex noctilio, was tested in known (Pinus taeda) and predicted novel (P. elliottii subsp. elliottii × P. caribaea var. hondurensis) hybrid host taxa. Trials were established in the field to simulate nematode dispersal both naturally by infected wasps and following commercial inoculation, as well as in the laboratory under controlled conditions. Nematodes showed reduced survival in hybrid pine compared with P. taeda for all tree-associated treatments, but performed equivalently in petri-dish bioassays containing substrate of each taxon. Growth of Amylostereum areolatum, the food source of D. siricidicola was lower on plates containing ground hybrid substrate than on plates containing ground P. taeda. Some physical differences were found between taxa, including differences in bordered pit diameters, tracheid widths, and basic density, but these did not consistently explain reduced performance. More plant secondary compounds (predominantly oleoresins) were present in hybrid taxa than in P. taeda, and in standing trees compared with felled trees. Our results suggested that D. siricidicola may not be as effective in hybrid pine taxa for the biological control of S. noctilio as it is in its current known host taxa, possibly because of reduced growth of its food source, A. areolatum in hybrid pine.

Influence Of The Stage Of Ripeness On The Composition Of Iridoids And Phenolic Compounds In Genipap (genipa Americana L.).

Genipap fruits, native to the Amazon region, were classified in relation to their stage of ripeness according to firmness and peel color. The influence of the part of the genipap fruit and ripeness stage on the iridoid and phenolic compound profiles was evaluated by HPLC-DAD-MS(n), and a total of 17 compounds were identified. Geniposide was the major compound in both parts of the unripe genipap fruits, representing >70% of the total iridoids, whereas 5-caffeoylquinic acid was the major phenolic compound. In ripe fruits, genipin gentiobioside was the major compound in the endocarp (38%) and no phenolic compounds were detected. During ripening, the total iridoid content decreased by >90%, which could explain the absence of blue pigment formation in the ripe fruits after their injury. This is the first time that the phenolic compound composition and iridoid contents of genipap fruits have been reported in the literature.

Antimycobacterial and cytotoxicity activity of synthetic and natural compounds

Antimycobacterial and cytotoxicity activity of synthetic and natural compounds. Secondary metabolites from Curvularia eragrostidis and Drechslera dematioidea, Clusia sp. floral resin, alkaloids from Pilocarpus alatus, salicylideneanilines, piperidine amides, the amine 1-cinnamylpiperazine and chiral pyridinium salts were assayed on Mycobacterium tuberculosis H37Rv. N-(salicylidene)-2-hydroxyaniline was the most effective compound with a minimal inhibitory concentration (MIC) of 8 µmol/L. Dihydrocurvularin was moderately effective with a MIC of 40 µmol/L. Clusia sp. floral resin and a gallocatechin-epigallocatechin mixture showed MIC of 0.02 g/L and 38 µmol/L, respectively. The cytotoxicity was evaluated for N-(salicylidene)-2-hydroxyaniline, curvularin, dihydrocurvularin and Clusia sp. floral resin, and the selectivity indexes were > 125, 0.47, 0.75 and 5, respectively.

Polar organic marker compounds in atmospheric aerosols during the LBA-SMOCC 2002 biomass burning experiment in Rondonia, Brazil: sources and source processes, time series, diel variations and size distributions

Measurements of polar organic marker compounds were performed on aerosols that were collected at a pasture site in the Amazon basin (Rondonia, Brazil) using a high-volume dichotomous sampler (HVDS) and a Micro-Orifice Uniform Deposit Impactor (MOUDI) within the framework of the 2002 LBA-SMOCC (Large-Scale Biosphere Atmosphere Experiment in Amazonia - Smoke Aerosols, Clouds, Rainfall, and Climate: Aerosols From Biomass Burning Perturb Global and Regional Climate) campaign. The campaign spanned the late dry season (biomass burning), a transition period, and the onset of the wet season (clean conditions). In the present study a more detailed discussion is presented compared to previous reports on the behavior of selected polar marker compounds, including levoglucosan, malic acid, isoprene secondary organic aerosol (SOA) tracers and tracers for fungal spores. The tracer data are discussed taking into account new insights that recently became available into their stability and/or aerosol formation processes. During all three periods, levoglucosan was the most dominant identified organic species in the PM(2.5) size fraction of the HVDS samples. In the dry period levoglucosan reached concentrations of up to 7.5 mu g m(-3) and exhibited diel variations with a nighttime prevalence. It was closely associated with the PM mass in the size-segregated samples and was mainly present in the fine mode, except during the wet period where it peaked in the coarse mode. Isoprene SOA tracers showed an average concentration of 250 ng m(-3) during the dry period versus 157 ng m(-3) during the transition period and 52 ng m(-3) during the wet period. Malic acid and the 2-methyltetrols exhibited a different size distribution pattern, which is consistent with different aerosol formation processes (i.e., gas-to-particle partitioning in the case of malic acid and heterogeneous formation from gas-phase precursors in the case of the 2-methyltetrols). The 2-methyltetrols were mainly associated with the fine mode during all periods, while malic acid was prevalent in the fine mode only during the dry and transition periods, and dominant in the coarse mode during the wet period. The sum of the fungal spore tracers arabitol, mannitol, and erythritol in the PM(2.5) fraction of the HVDS samples during the dry, transition, and wet periods was, on average, 54 ng m(-3), 34 ng m(-3), and 27 ng m(-3), respectively, and revealed minor day/night variation. The mass size distributions of arabitol and mannitol during all periods showed similar patterns and an association with the coarse mode, consistent with their primary origin. The results show that even under the heavy smoke conditions of the dry period a natural background with contributions from bioaerosols and isoprene SOA can be revealed. The enhancement in isoprene SOA in the dry season is mainly attributed to an increased acidity of the aerosols, increased NO(x) concentrations and a decreased wet deposition.

Secondary metabolites produced by Propionicimonas sp (ENT-18) induce histological abnormalities in the sclerotia of Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is a highly aggressive pathogen that causes great economic losses, especially in temperate climates. Several biological control agents are available, but actinobacteria have seldom been used to control this fungus. Our objective was to evaluate the efficiency and ultrastructural effects of the secondary metabolites produced by the ant-associated actinobacterium Propionicimonas sp. ENT-18 in controlling the sclerotia of S. sclerotiorum. We demonstrated total inhibition of sclerotia treated with 62.5 mu g/10 mu l of an ethyl acetate extract of compounds produced by ENT-18, and calculated an LC(50) of 1.69 mu g/sclerotia. Histological and ultrastructural analysis indicated that the cells of the treated sclerotia were severely damaged, suggesting direct action of the biomolecule(s) produced by the actinobacterium ENT-18 on the cell structure of the medullae and rind cell wall. This is the first report demonstrating a novel property of Propionicimonas sp.-antifungal activity against S. sclerotiorum.

Volatile organic compounds produced by Saccharomyces cerevisiae inhibit the in vitro development of Guignardia citricarpa, the causal agent of citrus black spot

Due to the low chemical control effectiveness of citrus black spot, caused by the fungus Guignardia citricarpa at postharvest, and to the search for alternative control methods, this study aimed to evaluate the in vitro effect of volatile organic compounds (VOCs), produced by yeast Saccharomyces cerevisiae, on G. citricarpa. It was observed that the yeast strains evaluated acted as antagonists by VOC production, whose maximum inhibitory capacity was as high as 87.2%. The presence of fermentable carbon sources in the medium was essential for the bioactive VOC production by the yeast. The analysis of VOCs produced in PDA medium by SPME-GC-MS indicated the presence of high quantities of alcohols as well as esters. An artificial VOC mixture prepared on the basis of the composition of the VOCs mimicked the inhibitory effects of the natural VOCs released by S. cerevisiae. Thus, the VOCs produced by the yeast or the artificial mixtures can be a promising control method for citrus black spot or others postharvest diseases.

Fungal tyrosine betaine, a novel secondary metabolite from conidia of entomopathogenic Metarhizium spp. fungi

Fungi, including the entomopathogenic deuteromycete Metarhizium anisopliae, produce a wide diversity of secondary metabolites that either can be secreted or stored in specific developmental structures, e.g., conidia. Some secondary metabolites, such as pigments, polyols and mycosporines, are associated with pathogenicity and/or fungal tolerance to several stress-inducing environmental factors, including temperature and solar radiation extremes. Extracts of M. anisopliae var. anisopliae (strain ESALQ-1037) conidia were purified by chromatographic procedures and the isolated compounds analyzed by (1)H and (13)C nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. LC-MS analyses were carried out to search for mycosporines (the initial targets), but no compounds of this class were detected. A molecule whose natural occurrence was previously undescribed was identified. It consists of betaine conjugated with tyrosine, and the structure was identified as 2-([1-carboxy-2-(4-hydroxyphenyl)ethyl]amino)-N,N,N-trimethyl-2-oxoethanammonium. mannitol was the predominant compound in the alcoholic conidial extract, but no amino acids other than tyrosine were found to be conjugated with betaine in conidia. The fungal tyrosine betaine was detected also in conidial extracts of three other M. anisopliae var. anisopliae (ARSEF 1095, 5626 and 5749) and three M. anisopliae var. acridum isolates (ARSEF 324, 3391 and 7486), but it was not detected in Aspergillus nidulans conidial extract (ATCC 10074). (C) 2010 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Health promoting and sensory properties of phenolic compounds in food

Phenolic compounds have been extensively studied in recent years. The presence of these compounds in various foods has been associated with sensory and health promoting properties. These products from the secondary metabolism of plants act as defense mechanisms against environmental stress and attack by other organisms. They are divided into different classes according to their chemical structures. The objective of this study was to describe the different classes of phenolic compounds, the main food sources and factors of variation, besides methods for the identification and quantification commonly used to analyze these compounds. Moreover, the role of phenolic compounds in scavenging oxidative stress and the techniques of in vitro antioxidant evaluation are discussed. In vivo studies to evaluate the biological effects of these compounds and their impact on chronic disease prevention are presented as well. Finally, it was discussed the role of these compounds on the sensory quality of foods.

Marine cyanobacteria compounds with anticancer properties: a review on the implication of apoptosis

Marine cyanobacteria have been considered a rich source of secondary metabolites with potential biotechnological applications, namely in the pharmacological field. Chemically diverse compounds were found to induce cytoxicity, anti-inflammatory and antibacterial activities. The potential of marine cyanobacteria as anticancer agents has however been the most explored and, besides cytotoxicity in tumor cell lines, several compounds have emerged as templates for the development of new anticancer drugs. The mechanisms implicated in the cytotoxicity of marine cyanobacteria compounds in tumor cell lines are still largely overlooked but several studies point to an implication in apoptosis. This association has been related to several apoptotic indicators such as cell cycle arrest, mitochondrial dysfunctions and oxidative damage, alterations in caspase cascade, alterations in specific proteins levels and alterations in the membrane sodium dynamics. In the present paper a compilation of the described marine cyanobacterial compounds with potential anticancer properties is presented and a review on the implication of apoptosis as the mechanism of cell death is discussed.

Compounds identified on hexane and dichloromethane extracts of Salicornia ramosissima

3rd Portuguese Meeting on Medicinal Chemistry and 1st Portuguese-Spanish-Brazilian Meeting on Medicinal Chemistry, Aveiro, 28-30 Novembro 2012.