The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species. In this work we describe the genome of H. seropedicae SmR1, a bacterium capable of fixing nitrogen and promoting the growth of important plant crops such as maize, rice, and sugar cane. Several investigations have shown that H. seropedicae supplies fixed nitrogen to the associated plant and increases grain productivity up to 50%. In the genome of H. seropedicae, we identified all the genes involved in the nitrogen fixation process and its regulation and, in addition, genes potentially involved in the establishment of efficient interaction with the host plant. Our analyses also revealed that this bacterium has a highly versatile metabolism capable of synthesizing and degrading a large number of organic and inorganic compounds. We believe that the knowledge of the genome of this bacterium will direct research to a better understanding of this important endophytic organism and allow the construction of new strains with enhanced agronomic efficiency.

Baccharis dracunculifolia DC (Asteraceae) is a Brazilian native bush tree, and its leaf essential oil has been reported to possess some biological activities, but the antimicrobial activity of its aerial part essential oil at the flowering period is unknown or little studied, mainly against agents that cause foodborne diseases. Thus, this study aimed to determine the chemical composition and evaluate the antimicrobial activity of the essential oil of B. dracunculifolia aerial part at flowering period. This essential oil was obtained by hydro distillation and its chemical composition was determined by gas chromatography coupled with mass spectrometry (GC–MS). The minimum inhibitory concentration, minimum bactericidal concentration, and minimum fungicidal concentration of the essential oil were evaluated against eight bacteria and eight fungi using 96-well microtiter plates. The essential oil yield was 1.8 ± 0.07%, and spathulenol (27%) and trans-nerolidol (23%), both oxygenated sesquiterpenes, were the major compounds found among 30 chemical constituents identified. The essential oil presented bacteriostatic and bactericidal activities, mainly against Staphylococcus aureus, Bacillus cereus and Pseudomonas aeruginosa, and also fungistatic and fungicidal activities. However, its antibacterial activity was more effective than the antifungal one by using the essential oil at lower concentrations. Essential oil of B. dracunculifolia may be a potential alternative for food applications in order to reduce synthetic chemicals in a more sustainable food industry.

Parsley [Petroselinum crispum (Mill.) Fuss] is regarded as an aromatic, culinary, and medicinal plant and is used in the cosmetic, food, and pharmaceutical industries. However, few studies with conflicting results have been conducted on the antimicrobial activity of parsley essential oil. In addition, there have been no reports of essential oil obtained from parsley aerial parts, except seeds, as an alternative natural antimicrobial agent. Also, microorganism resistance is still a challenge for health and food production. Based on the demand for natural products to control microorganisms, and the re-evaluation of potential medicinal plants for controlling diseases, the objective of this study was to determine the chemical composition and antibacterial and antifungal activities of parsley essential oil against foodborne diseases and opportunistic pathogens. Seven bacteria and eight fungi were tested. The essential oil major compounds were apiol, myristicin, and b-phellandrene. Parsley essential oil had bacteriostatic activity against all tested bacteria, mainly Staphylococcus aureus, Listeria monocytogenes, and Salmonella enterica, at similar or lower concentrations than at least one of the controls, and bactericidal activity against all tested bacteria, mainly S. aureus, at similar or lower concentrations than at least one of the controls. This essential oil also had fungistatic activity against all tested fungi, mainly, Penicillium ochrochloron and Trichoderma viride, at lower concentrations than the ketoconazole control and fungicidal activity against all tested fungi at higher concentrations than the controls. Parsley is used in cooking and medicine, and its essential oil is an effective antimicrobial agent.