The isolation of Escherichia coli from food is a major concern. Pathogenic strains of these bacteria cause diseases which range from diarrhea to hemolytic-uremic syndrome. Therefore the virulence genes in E. coli isolates from the mussel ( Mytella guyanensis) commercialized in Cachoeira, Bahia, Brazil were investigated. Samples were purchased from four vendors: two from supermarkets and two from fair outlets. They were conditioned into isothermal boxes with reusable ice and transported to the laboratory for analysis. E. coli strains were isolated in eosin methylene blue agar, preserved in brain-heart infusion medium with 15% glycerol and stored at -20 °C, after microbiological analysis. Virulence genes in the isolated strains were identified by specific primers, with Polymerase Chain Reaction. Twenty-four isolates were obtained, with a prevalence of elt gene, typical from enterotoxigenic infection, in 75% of the isolates. The stx and bfpA genes, prevalent in enterohemorragic and enteropathogenic E. coli, respectively, were not detected. The occurrence of elt virulence-related gene in the E. coli isolates of Mytella guyanensis reveals urgent improvement in food processing, including good handling practices, adequate storage and cooking before consumption, to ensure consumer’s health.

Evaluating the vigour and viability of seeds can help in the production of seed lots with proven high physiological potential. In this regard, the tetrazolium (TZ) test is efficient, rapid and inexpensive; however, it not been fully explored for forest species. Further development of species-specific methodologies is required in order to maximise the test efficacy. The objective of this work was to define a tetrazolium test protocol to evaluate the vigour and viability of Genipa americana L seeds. Fruits and seeds were characterised for biometry and initial water content before and after hydration. Germination, germination speed index, electrical conductivity and seedling emergence was also performed. For the TZ test, G. americana seeds were cut longitudinally and submitted to different seed pre-conditioning methods (with and without 24 hours imbibition), different TZ concentrations (0.05, 0.075, 0.10 and 0.25%) and three immersion periods (2, 3 and 4 hours). The tetrazolium test allowed adequate evaluation of seed vigour levels (Viable; Viable and non-vigourous; and Non-viable). Immersion of non-imbibed seeds in 0.10% TZ solution, for three hours is the most efficient protocol for evaluating the vigour and viability of G. americana seeds.

Considering the growing demand for seed production and seedlings for forest restoration, addressing the implications of landscape changes regarding germination of native species becomes of great value for directing seed collections. The objective of this study is to evaluate the influence of seed collection environment on germination and biometry of fruits and diaspores of Bowdichia virgilioides. Fruits were collected in two forest fragments with distinct characteristics (forest I, open canopy; and forest II, closed canopy), and in isolated trees in pastures. Fruit and seed biometry of the three collection environments was carried out, and a germination test was conducted in a completely randomized design with three treatments (forest I, forest II, and open area) and twenty replicates. Collection site, and therefore changes in forest cover, influences the biometry of fruits and seeds, resulting in lighter seeds and fruits with a smaller size in the fragment with a recent history of disturbance (forest I), as well as the vigor of diaspores of Bowdichia virgilioides. Seeds from forest I expressed a greater vigor, while seeds from the pasture area presented a higher propensity to death and formation of abnormal seedlings. For the production of seedlings and commercialization of seeds for forest restoration, the environment of origin of seeds should be taken into account. It is not recommended to use lots of seedlings from Bowdichia virgilioides seeds from isolated trees, such as those located on pastures and roads.

The biometric characterization of fruits and seeds, obtaining optimum temperatures and photoperiods for germination and the definition of numbers and counting intervals in the germination tests of Psidium cauliflorum were the objectives of this work. Fruits were obtained from four matrices located in the Environmental Protection Area of Lago de Pedra do Cavalo, in São Gonçalo dos Campos-BA. The following temperatures were tested: 25 °C; 30 °C; and 25-30 °C, in addition to three light conditions: absence of light; 8 h photoperiod; and 12 h photoperiod. One kilogram of fruit contains about 260 fruits and 1.344 seeds. Germination performance was higher at the alternating temperatures of 25-30 °C, in the presence of light (8 h photoperiod). The germination test lasted 77 days, with the first count at 21 days and subsequent counts at 15 day-intervals.

The ethanol test supplies information on physiological problems related to seed deterioration. The test optimization is crucial for its application in the seed analysis routine. This study aimed to evaluate vigor test for Plathymenia reticulataseeds based on ethanol production in order to establish execution guidelines and verify its relationship with other seed vigor tests. Seed lots were subjected to germination and vigor tests, and seed coat evaluation. Ethanol production assessment was carried out based on two trials testing water volumes for imbibition (0.25; 0.5; 0.75; 1.00; and 1.25 mL), reading periods (2, 4, 6, 8, 24, and 48 h), and seed quantities (5, 10, and 15). There was a distinction in physiological potential between the lots, indicated by the ethanol test and other traditionally used tests. The ethanol test was efficient for vigor assessment in Plathymenia seeds, as were the other vigor tests, when conducted with 15 seeds imbibed in a volume of water 2.5 times their mass for 48 h. The vigor test based on ethanol production proved reliable and it is recommended for use in a system of seed production and commercialization in nurseries and forestry companies.