Francine Souza Alves da Fonseca

Ecological Interactions Shape the Dynamics of Seed Predation in Acrocomia aculeata (Arecaceae)

Background The complex network of direct and indirect relationships determines not only the species abundances but also the community characteristics such as diversity and stability. In this context, seed predation is a direct interaction that affects the reproductive success of the plant. For Acrocomia aculeata, the seed predation by Pachymerus cardo and Speciomerus revoili in post-dispersal may destroy more than 70% of the propagules and is influenced by the herbivory of the fruits during pre-dispersal. Fruits of plants with a higher level of herbivory during pre-dispersal are less attacked by predators in post-dispersal. We proposed a hypothesis that describes this interaction as an indirect defense mediated by fungi in a multitrophic interaction. As explanations, we proposed the predictions: i) injuries caused by herbivores in the fruits of A. aculeata favor fungal colonization and ii) the colonization of A. acuelata fruit by decomposing fungi reduces the selection of the egg-laying site by predator. Methodology/Principal Findings For prediction (i), differences in the fungal colonization in fruits with an intact or damaged epicarp were evaluated in fruits exposed in the field. For prediction (ii), we performed fruit observations in the field to determine the number of eggs of P. cardo and/or S. revoili per fruit and the amount of fungal colonization in the fruits. In another experiment, in the laboratory, we use P. cardo females in a triple-choice protocol. Each insect to choose one of the three options: healthy fruits, fruits with fungus, or an empty pot. The proposed hypothesis was corroborated. Fruits with injuries in the epicarp had a higher fungal colonization, and fruits colonized by fungi were less attractive for egg-laying by seed predators. Conclusion/Significance This study emphasizes the importance of exploring the networks of interactions between multitrophic systems to understand the dynamics and maintenance of natural populations.

Identification of oxidoreductases from the petroleum Bacillus safensis strain

Highlights • A bacterium responsible for degradation of the petroleum aromatic fractions was isolated.• The bacterium was identified as Bacillus safensis.• Enzymatic assays revealed the presence of two oxidoreductases.• The B. safensis strain can be used for bioremediation of petroleum-polluted environment.

Antimicrobial activity and acute and chronic toxicity of the essential oil of Lippia origanoides

Currently, there is a growing interest in medicinal plants, because of an increased demand for alternate therapies. In this study, the antimicrobial activity and toxicity of the essential oil of Lippia origanoides (L. origanoides) were investigated. The essential oil of L. origanoides was extracted by steam-dragging distillation and its constituents were identified by chromatography coupled with mass spectrometry. Among the 15 compounds identified, the most abundant were carvacrol (29.00%), o-cymene (25.57%), and thymol methyl ether (11.50%). The essential oil was studied in antimicrobial assays to determine the MIC and MBC. The results indicated that a concentration of 120μL/mL of oil was sufficient to inhibit the growth of the following microorganisms: Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923) and Salmonella cholerasuis (ATCC 10708). Acute and chronic toxic effects of orally administered oil were investigated in Wistar rats by using standard methods. Doses of 30, 60 and 120mg/kg of the essential oil did not induce significant changes in weight, behavior or hematological and biochemical parameters in the animals. There were no signs of any histopathological changes to the liver, kidneys or heart of the treated rats, suggesting that Lippia origanoides oil is non-toxic after oral administration in acute or chronic toxicity studies. The results obtained in this study show that the essential oil of L. origanoides has a high safety margin, with no detectable toxic effects in rats treated with doses to 120mg/kg. In addition, L. origanoides oil demonstrated potent antimicrobial activity against S. aureus, E. coli and S. cholerasuis. Based on these findings, this essential oil may have practical application as a veterinary antimicrobial.

Genome Sequence of Bacillus safensis CFA06, Isolated from Biodegraded Petroleum in Brazil

ABSTRACT Bacillus safensis is a microorganism recognized for its biotechnological and industrial potential due to its interesting enzymatic portfolio. Here, as a means of gathering information about the importance of this species in oil biodegradation, we report a draft genome sequence of a strain isolated from petroleum.

Growing of tropical black sage and chemical composition of the essential oil

The objective of this study was to evaluate the influence of spacing and mulch on biomass production, chemical composition and production of essential oil of tropical black sage. A randomized block design was used in a 2×2 factorial scheme: two spacings (1.6 × 0.5 m and 1.0 × 0.5 m), with and without mulch, using five replications. In the end, the combination of spacing and presence and absence of mulch did not influence the height and diameter of the stem. However, it has influenced fresh matter: 8765.00 kg ha-1 (1.0 × 0.5 m, with mulch) and 6112.50 kg ha-1 (1.6 × 0.5 m, without mulch). The spacing 1.0 x 0.5 m was what provided higher dry matter (3052.14 kg ha-1). For the production of essential oil, the combination of spacing of 1.0 × 0.5 m, with mulch provided greater production (484.50 kg ha-1). Twenty-seven compounds were detected, of which 23 were identified, most of which were sesquiterpenes and monoterpenes. The α-pinene and the β-caryophyllene showed higher abundances in all samples, regardless of the treatment. The contents of α-humulene was sufficient to meet the requirements of the pharmaceutical industry. Thus, the alteration in soil spacing and mulch influences the production of essential oil and biomass, but it does not influence the relatives amount of the α-humulene and of the β-caryophyllene.

Volatile Compounds from the Bark Bugs Phloea subquadrata and Phloeophana longirostris (Heteroptera: Phloeidae)

Phloea subquadrata and Phloeophana longirostris are subsocial species that differ from each other in their host plants and degrees of aggregation. Until recently, only ten low-molecular weight compounds, a sesquiterpene, and dimers of (E)-4-oxo-2-hexenal had been reported from the contents of P. subquadrata glands. Here, the main goal was to distinguish the volatile compounds released by adult males, adult females and nymphs of the two species. The analyses revealed 103 compounds, of which 44 were exclusive to Phloeophana longirostris and 15 were exclusive to Phloea subquadrata. The data were analyzed by chemometric methods, which discriminated the phloeid species by developmental stage and sex. (E)-2-Hexenal, (E)-4-oxo-2-hexenal and (E)-2-octenal were found in both species. Adult individuals were characterized by the presence of methyl 2-methylbutanoate, (E)-2-hexenyl acetate and 2-hexenyl butanoate, and nymphs were characterized by 5-ethyl-2(3H)-furanone and (E)-2-octenal. There was chemical distinction between volatiles of adults and nymphs of the two species studied.

Teor e composição química do óleo essencial de erva-baleeira (Varronia curassavica Jaqc.) em função dos horários de coleta

A erva-baleeira (Varronia curassavica Jaqc.) e uma importante planta medicinal, com ocorrencias em varios biomas brasileiros, dela e possivel extrair oleo essencial utilizado na producao de fitoterapicos. O objetivo deste trabalho foi estudar o efeito do horario de coleta das folhas sobre o teor e os constituintes quimicos do oleo essencial da V. curassavica. As folhas foram obtidas da colecao do germoplasma do Horto Medicinal do Instituto de Ciencias Agrarias da Universidade Federal de Minas Gerais (ICA/UFMG). Os tratamentos constaram de cinco horarios de coleta (6:00, 9:00, 12:00, 15:00 e 18:00 horas) e tres repeticoes, utilizando o delineamento experimental inteiramente casualizado. O oleo essencial foi extraido pelo metodo de hidrodestilacao, utilizando-se o sistema Clevenger e a constituicao quimica determinada por cromatografia em fase gasosa acoplada a espectrometria de massas (CG/EM). O teor do oleo essencial nao sofreu influencia do horario de coleta. Entretanto, o horario de coleta influenciou a composicao quimica do oleo essencial de erva-baleeira. Os compostos majoritarios em todos os horarios de coleta foram β-cariofileno (22,6 a 27,4%), elixeno (14,9 a 17,2%) e γ-muuroleno (9,1 a 9,8%). Ja o composto de menor abundância relativa, sabineno (1,1 %), apresentou ocorrencia apenas as 6 h da manha.

(E)-4-Oxo-2-hexenal Dimers in the Scent Glands of the Bark Bug Phloea subquadrata (Heteroptera, Phloeidae)

Bark bugs belonging to the family Phloeidae are known for their camouflage on tree trunks. The nymphs store in dorsal abdominal glands defensive secretions with a pungent odor mainly constituted of (E)-2-hexenal, (E)-2-octenal, and (E)-4-oxo-2-hexenal. The metathoracic glands of adults (male and female) store (E)-2-hexen-1-ol and (E)-2-hexenyl acetate, which are less irritating than their corresponding aldehydes. Additional compounds of m/z 224 were detected in the scent glands of these insects and were previously suggested to be dimers of the (E)-4-oxo-2-hexenal. Thus, the aim of this study was to elucidate the details of the chemical structure of the dimers found in the scent glands of Phloea subquadrata. These dimers were obtained by synthesis and were compared with the natural products, confirming the dimeric structures of the latter. These (E)-4-oxo-2-hexenal dimeric compounds are novel and have not been reported before.