ISSN / EISSN : 2526-432X / 2526-4338
Published by: Acta Brasiliensis (10.22571)
Total articles ≅ 123
Latest articles in this journal
Acta Brasiliensis, Volume 6, pp 72-78; https://doi.org/10.22571/2526-4338620
The aim of this study was to determine concentrations of nitrogen (N) in two biomes, Atlantic Forest (AF) and Cerrado (CR), at the interface between terrestrial and aquatic ecosystems. This involved evaluating N in vegetation (litterfall), soil and water in small watersheds in environmental protection areas in northeastern Brazil. Soil chemical and physical analyzes were performed and mineralization and nitrification rates were determined. The forms of organic, inorganic and particulate nitrogen in water were determined by spectrophotometry. Two collections were carried out, one in the dry season (October and November 2019) and another in the rainy season (February and March 2020), in two environmental preservation areas, Estação Veracel Private Natural Heritage Reserve - (Atlantic Forest) and Chapada Diamantina National Park (Cerrado), with five small watersheds sampled in each biome. The N concentration in litterfall was similar in both biomes, with averages of 0.69%. In relation to soil and water, N concentrations were higher in AF compared to CR, with concentrations of 0.95 ± 0.40 and 0.59 ± 0.14 µg.Ng-1 of nitrate in the soils of AF and CR, respectively, and 3.53 ± 2.51 µM of nitrate in water in AF and 0.76 ± 0.78 µM in CR.
Acta Brasiliensis, Volume 6, pp 84-88; https://doi.org/10.22571/2526-4338621
The objective of this research was to perform a preliminary phytochemical study and investigate the toxicity, cytotoxicity and antibacterial activity of the species Tibouchina papyrus (Melastomataceae). The toxicity test was performed with the extracts against Artemia salina. The cytotoxic study was also performed against the following cell lines: promyelocytic leukemia (HL60), human colon carcinoma (HCT-116), breast carcinoma (MCF-7), prostate carcinoma (PC3), astrocytoma (SNB-19) and non-tumor cells (L929). Last, antibacterial activity was assessed through against Staphylococcus epidermidis (25923), Staphylococcus aureus (12228), Escherichia coli (25312) and Pseudomonas aeruginosa (27853). The phytochemical investigation indicated the presence of these metabolite groups: flavonoids, triterpenes, steroids and tannins. The methanolic extracts showed moderate antibacterial activity against S. aureus, S. epidermidis and P. aeruginosa. T. papyrus extracts showed high cytotoxic activity against promyelocytic leukemia cell lines (80.43 to 93.31%). The other lines did not reveal good activity against the extracts tested.
Acta Brasiliensis, Volume 6, pp 95-100; https://doi.org/10.22571/2526-4338585
The objective of this work was to evaluate the physicochemical characteristics, the bioactive compounds and the antioxidant potential of honey produced by Africanized bees (Apis mellifera L.) from municipalities in western Paraná state. Sixty-six samples of honey were analyzed from October 2018 to August 2019. The physicochemical parameters evaluated were: color, moisture, hydroxymethylfurfural, pH and free acidity, with mean values of 0.36±0.24nm, 18 .80±1.01%, 10.34±3.24mg.kg-1, 4.01±0.18 and 17.36±4.11 meq.kg-1, respectively. The bioactive compounds (phenolic compounds and flavonoids) and the antioxidant activity were also analyzed, and the mean values of 16.34±7.41mg.GAE 100 g-1 were observed for Total Phenols, 21.35±9.63mg.QE 100 g-1 for flavonoids and 0.09±0.03µmol.TE g-1 for antioxidant activity (DPPH). The honey samples were influenced by their phytogeographic origin and have antioxidant potential.
Acta Brasiliensis, Volume 6, pp 110-113; https://doi.org/10.22571/2526-4338594
Termites are known as wood consumers, although some species eat other substrates. Assessing resource selection is important to understanding their biology. The present study provides information on the foraging behavior of Constrictotermes cyphergaster (Blattaria, Termitidae) in a dry forest area of Caatinga in Brazil. We aimed to verify the frequency of resource exploitation by termites as a function of environmental and soil temperatures. We found no significant differences in resource exploitation as a function of temperature, which is interesting because this variable is often reported as modulating foraging activity in some other termite species. This species forages on open trails at high temperatures in the Brazilian semi-arid zone. Environmental changes may affect the dynamics of their behavior and, consequently, the ecosystem, since C. cyphergaster influences the carbon cycle and can modify the soil. Our study provides a basis for future research intending to understand the adaptations of this termite to live in the drylands.
Acta Brasiliensis, Volume 6, pp 106-109; https://doi.org/10.22571/2526-4338589
The release calls carry species-specifics characteristics that can be used for the diagnosis of closely related species. Despite its importance, for the Lophyohylini tribe, this type of call is known only for two species. Corythomantis greeningi is a species widely distributed in xeric and sub-humid regions of northeastern Brazil. Herein, we describe for the first time the release call of C. greeningi recorded in the Pedro II municipality, state of Piauí, northeastern Brazil. The release call, emitted during handling in its the axillary region, was structurally and quantitatively different from the advertisement call, presenting a lower number of pulses per note and a lower dominant frequency. This work represents an important contribution to the intra and interspecific communication mechanisms of the species.
Acta Brasiliensis, Volume 6, pp 79-83; https://doi.org/10.22571/2526-4338593
Protium is the most frequent genus of Burseraceae in the Adolpho Ducke Forest Reserve (Manaus, Amazonas), which is where its species were previously identified and mapped and this has favored various studies of this central Amazon forest. A number of P. divaricatum Engl., P. opacum Swart and P. strumosum Daly trees were selected with the objective of providing information about their chemical and biological aspects. Resin exudation was stimulated with the use of ethephon and the essential oils from the aerial parts and the resin were evaluated using GC. The occurrence of galls was also registered. The hydrocarbon sesquiterpene ß-caryophyllene was detected in high percentages in the essential oils of leaves and twigs of P. divaricatum (52.75% and 14.74%) and P. opacum (39.55% and 17.86%), respectively. The predominant oxygenated sesquiterpenes were spathulenol in the leaves (19.52%) and twigs (31.29%) of P. divaricatum, in addition to khusimone (32.36%) in the twigs of P. opacum. Monoterpenes were identified in the essential oils of the P. strumosum resin, with p-cymene (58.97%) predominating in the naturally exuded resin, limonene (61.45%) and p-cimen-8-ol (53.92%) in the resin of the first and second extraction with ethephon, respectively. On the trees, galls were identified that will help in the identification of the three species.
Acta Brasiliensis, Volume 6, pp 101-105; https://doi.org/10.22571/2526-4338577
Ceylon gooseberry (Dovyalis hebecarpa Warb) is an important and valuable food source in the diet of several countries worldwide with a potential to positively impact nutritional security. This study aimed to evaluate the physicochemical attributes, bioactive compounds, and antioxidant capacity of D. hebecarpa fruits grown in Marechal Cândido Rondon/PR. The following parameters were assessed: fresh weight, longitudinal and transverse length, LD/TD (format index), yield in pulp, peel, and seed, soluble solids, titratable acidity, SS/TA (flavor index), pH, ascorbic acid, total carotenoids, yellow flavonoids, total anthocyanins, total chlorophyll, phenolic compounds, and antioxidant capacity (DPPH and FRAP). The review and results of study on ripe fruits of D. hebecarpa in Marechal Cândido Rondon/PR revealed that it contains significant levels of soluble solids (18.25 °Brix), good pulp yield (90.19%), and high levels of ascorbic acid (142.09 mg/100g-1 of pulp) and total anthocyanins (94.13 mg/100g-1 of peel). This information confirms that the fruits of D. hebecarpa can be successfully used for the formulation and development of new products, in addition to the utilization of other parts, such as peels and seeds.
Acta Brasiliensis, Volume 6, pp 89-94; https://doi.org/10.22571/2526-4338619
Heavy metal pollution is an serious environmental problem because they have toxic effects on living organisms. In recent years, the use of microbial biosorbents to remove heavy metal pollution have studied. Many biological materials are used to remove copper ions. In this study, the biosorption capacity of lyophilized Pantoea agglomerans for Cu (II) ions were investigated under various conditions (initial pH, contact time, initial heavy metals ion concentration). The monocomponent biosorption data have been analyzed using isotherm (Freundlich and Langmuir) and kinetic models. The highest copper uptake capacity of the biomass was obtained at the initial copper concentration of 250 mgL-1 at pH 5.0 and contact time 90th minute. The equilibrium data correlated well with the Langmuir and Freundlich model. It was found that the pseudo-second-order kinetic model fitted the experimentally obtained data. Liyofilized P. agglomerans biomass appears to be an inexpensive and efficient biosorbent for the removal of Cu (II) from aqueous solutions.
Published: 30 May 2022
Acta Brasiliensis, Volume 6, pp 43-48; https://doi.org/10.22571/2526-4338580
The quality of water used for human consumption related to the absence of coliforms, which, which may cause diseases and exhibit antimicrobial resistance, a frequent issue in places with poor or non-existent environmental sanitation. The present study evaluated the concentrations of total and thermotolerant coliforms in rivers and wells in Curitibanos (SC), as well as the phenotypic resistance to four antibiotics (Ampicillin, Ampicillin+Sulbactam, Ciprofloxacin and Tetracycline), during four seasons of the year. Analysis of variance was performed and means were separated by the Scott-Knott test, at 5% error probability. In rivers, the highest values of fecal coliforms were recorded in summer and winter, and resistance to ampicillin and ampicillin+sulbactam was higher in autumn, while resistance to tetracycline was more prevalent in summer. In the wells, the highest averages of fecal coliforms occurred in summer, autumn and winter, and the highest levels of resistance were observed against ampicillin, in autumn. Overall, rivers had more compromised water quality, compared to wells, emphasizing the need to preserve aquatic resources in order to decrease evolution of resistance to antibiotics and diseases and deaths cause by superbacteria that may be ingested with contaminated water.
Published: 30 May 2022
Acta Brasiliensis, Volume 6, pp 26-34; https://doi.org/10.22571/2526-4338583
The effect of tropospheric ozone on the physiology of plants has been well established using physicochemical analysis and visual assessment. One of the main metabolic processes, in plants that is affected by ozone, is photosynthesis. This in turn affects a number of secondary processes required for the survival of plants. This study focused on two main aspects; the qualitative determination of damage through visual assessment and the quantification of damage through the determination of the content of chlorophyll and other quality parameters using spectrophotometric techniques in a number of plant species. Three distinct setups were considered, mainly rural, urban and semiurban, representing the topography of the islands of Malta and Gozo. It was observed that chlorosis was not the sole factor contributing to the yellowing of the leaves. Another important finding was the correlation between ozone levels (50.18-69.35 ppb) and the anthocyanin content (2.57-28.99 mg/kg) of leaves. From the three plant species that were extensively studied (Nerium oleander, Pinus halepensis and Schinus terebinthifolius), the N. oleander exhibited promising results as a bioindicator for ozone-induced damage. Due to the presence of this ornamental plant in rural and urban areas, it can be used by researchers and authorities as a tool for assessment of tropospheric ozone levels.