Cepa Seeds Research Articles

Optimizing intermittent micro-aeration as a strategy for enhancing aniline anaerobic biodegradation: kinetic, ecotoxicity, and microbial community dynamics analyses.

Groundwater and soil contamination by aromatic amines (AAs), used in the production of polymers, plastics, and pesticides, often results from improper waste disposal and accidental leaks. These compounds are resistant to anaerobic degradation; however, micro-aeration can enhance this process by promoting microbial interactions. In batch assays, anaerobic degradation of aniline (0.14 mM), a model AA, was tested under three micro-aeration conditions: T30, T15, and T10 (30, 15, and 10 min of micro-aeration every 2 h, respectively). Aniline degradation occurred in all conditions, producing both aerobic (catechol) and anaerobic (benzoic acid) byproducts. The main genera involved in T30 and T15 were Comamonas, Clostridium, Longilinea, Petrimonas, Phenylobacterium, Pseudoxanthomonas, and Thiobacillus. In contrast, in T10 were Pseudomonas, Delftia, Leucobacter, and Thermomonas. While T30 and T15 promoted microbial cooperation for anaerobic degradation and facultative respiration, T10 resulted in a competitive environment due to dominance and oxygen scarcity. Despite aniline degradation in 9.4 h under T10, this condition was toxic to Allium cepa seeds and exhibited cytogenotoxic effects. Therefore, T15 emerged as the optimal condition, effectively promoting anaerobic degradation without accumulating toxic byproducts. Intermittent micro-aeration emerges as a promising strategy for enhancing the anaerobic degradation of AA-contaminated effluents.

BIOTESTING OF SOIL CONDITIONS AT THE TERRITORIES ADJACENT TO AIRPORTS

The development of civil aviation is accompanied by a constant increase in man-made load on the environment. The application of methods of bioindication and biotesting of anthropogenic and technogenic influences on the ecosystem components is one of the possible options for monitoring the state of the environment at territories subject to technogenic stress due to the activities of environmentally hazardous enterprises. To study the level of man-made impact of airport activities on the state of the soil (namely, phytotoxicity), at the territory adjacent to the airport "Kyiv" named after I. Sikorskyi International Airport from the upper and lower levels at different distances from the airport runway (from 5 m to 2 km) soil samples were taken using the envelope method. As a control (conditionally clean soil), a soil sample collected at the territory of Holosiiv Park (soil type: dark gray forest soils) was used. In total, six soil samples were analyzed. On the third day of germination the growth characteristics of Allium cepa seedlings were determined. Test parameters that were used to determine the phytotoxic effect: the percentage of seed germination, namely the energy of its germination, the length of the root and the length of the stem. The analysis of the obtained data on the germination of Allium cepa seeds showed that the lowest germination was recorded for the soil samples that were taken at a distance of 5 and 1500 m from the runway, which indicates an increased level of phytotoxic impact due to the activities of the airport.
 The greatest phytotoxic effect for the stem of Allium cepa seedlings was observed for the soil sample located at a distance of 5 m from the ZPS. For soil samples taken at a distance of 5 m to 1000 m, i.e. with distance from the runway of the airport, a decrease in the level of phytotoxicity of the soil is observed. Only when approaching the highway (at a distance of 1,000 m to 2,000 m) there was observed an increase in phytotoxicity of the soil again.
 Among the investigated samples of meristem tissues, the presence of mitotic activity of cells was observed in the meristems of root tip samples of onion seedlings germinated on soil samples that were taken at a distance of 5 m, 1500 m and 2000 m from the airport. The determined mitotic indices (MI) for these soil samples are as following: for a soil sample taken at a distance of 5 m, it was 2.9 %; for a soil sample taken at a distance of 1500 m was 2.6 %; for a soil sample taken at a distance of 2000 m was 2.6 %. The research results confirm the need for constant monitoring of the soil condition at these technogenically loaded territories, in order to increase the level of environmental safety of these territories.

AVALIAÇÃO DO POTENCIAL BIORREMEDIADOR DOS FUNGOS CANDIDA spp. E TRICHOPHYTON spp. NO TRATAMENTO DE LIXIVIADO PROVENIENTE DE ATERRO SANITÁRIO

This study compares the efficiency in reducing the toxicity of leachate from a landfill after the application of mycoremediation processes using Candida spp. and Trichophyton spp. fungi through bioassays with Allium cepa seeds. Experimental units were set up for leachate treatment with varying concentrations, inoculated with the selected fungi, and incubated. After incubation, bioassays were conducted using the liquid extract to inoculate ten Allium cepa seeds on Petri dishes. Subsequently, macroscopic analysis indices were calculated. The results revealed that Candida spp. yeast showed superior toxicity reduction results in all experimental units. In conclusion, among the analyzed genera, Candida spp. yeast demonstrates greater efficiency and holds promise for reducing the toxicity of landfill leachate.

Photon spectra effects tested on the vegetal model Allium cepa.

The use of artificial light sources in plants is considered a type of photobiomodulation (PBM), a trend in agriculture and food industries, aiming at decontamination, pest control, and increased production yield. However, literature lacks a broader assessment to address the effects of photon light spectra on plant characteristics. Here, we aimed to describe the effects of visible light, infrared, and ultraviolet light upon Allium cepa, a known bioindicator, under various light doses. Samples irradiated under visible and infrared light did not show cytotoxicity, genotoxicity, or mutagenicity in any of the evaluated doses. Light induction at 460 and 635 nm significantly stimulated root development of the test organism. In contrast, 254 nm irradiation proved to be cytotoxic, genotoxic, and mutagenic. This work reveals and quantifies the spectral response of A. cepa seeds, suggesting that it can be proposed as a model for future research on mechanisms of PBM in plants.

Genotoxicity and acute toxicity of 2-amino-5-benzylthiazole in complex with polymeric nanocarrier in Allium bioassay

Background. The search for optimal methods of selective and integral determination of various cytotoxic compounds in biological fluids and tissues, which would have high sensitivity and allow for quick and reliable assessment and detection of potentially cytotoxic components of substances with biologically active action, remains relevant today. It is known that chemotherapeutic agents can be released into the environment (air, surface water, sediments and soil) and cause adverse consequences (impact on the stability of ecosystems due to reduced viability of species). The aim of this work was to investigate the effect of thiazole derivative N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl1-benzofuran-2-carboxamide (BF1) conjugated with PEG-based polymeric nanoparticles (PEG-PN – Th1) on genotoxicity and acute toxicity in allium bioassay. Materials and Methods. Allium cepa ana-telophase assay was applied to monitor genotoxicity of the studied compounds. The acute toxic effects such as inhibition of cell division, seed germination and growth of Allium roots were estimated. A. cepa seeds (15 per each point) were germinated on the studied solutions of BF1, Th1 and Th2 (10 μM) for 5 days at 22 °C. The root growth and the percentage of inhibition of seed germination were calculated. In order to establish cyto- and genotoxicity of the studied compounds, we have determined the mitotic index and the relative amount of chromosomal aberrations. Results. BF1 had a significant inhibitory effect on root growth and seed germination at a concentration of 10 μM. The effect was eliminated when it was influenced by BF1 complex with a polymeric carrier. The free polymer does not have a negative effect on the studied parameters either. A significant decrease in the mitotic index and increase in the percentage of chromosomal aberrations was observed under the action of BF1 at a concentration of 10 µM. There was no significant change in the value of mitoitic index and percentage of chromosomal aberrations under the action of Th2 comp­lex or polymeric carrier Th1. Conclusions. The thiazole derivative in complex with a polymeric carrier at a concentration of 10 µM did not show acute toxicity in Allium cepa bioassay. Polymer carrier based on polyethylene glycol neutralized the negative effect of BF1 on the mitotic and phase indices of Allium root meristem cells; it also decreased the percentage of chromosomal aberrations.

Efficacy of Pulegone Pre-treatment in Mitigating the Oxidative Damage by NaCl Applied to Allium cepa L. Seeds

Background: Saline stress is an important environmental factor that limits the productivity of numerous agricultural crops, such as onion (Allium cepa L.), a vegetable present in gardens and used in various ways. Pulegone has been identified as a component that has a large number of biological functions. Objective: The aim of this study was to investigate the effect of pulegone (100 and 500 μg/mL) on the morphological and biochemical changes to onions induced by stressing seeds with NaCl. Method: Soil composition, emergence percentage and its inhibition, emergence speed index (ESI), leaf and root parameters, malondialdehyde (MDA) content, free iron content and chelation/oxidation capacity (Fe2+) were measured following 120 days of treatment. Results: Pulegone was able to significantly improve the changes in ESI caused by saline stress, not restoring other emergence parameters. The leaf size was also improved by the pulegone, which did not affect the morphological changes of the roots. Conclusion: Our results suggest that the use of pulegone is a viable treatment to mitigate the effects of salt stress on A. cepa seeds.

Environmentally realistic concentrations of eprinomectin induce phytotoxic and genotoxic effects in Allium cepa.

Eprinomectin, a veterinary drug within the family of avermectins, is widely used in the agricultural sector to combat a variety of parasites, mainly nematodes. However, only 10% of the drug is metabolized in the organism, so large quantities of the drug are released into the environment through urine and/or feces. Soil is the first and main environmental compartment to be contaminated by it, and nontargeted organisms can be affected. Thus, the present study aims to evaluate the phytotoxicity (through the evaluation of germination, root development, and germination speed) and genotoxicity (through an assessment of the induction of micronuclei and chromosomal aberrations) of eprinomectin. For the analyses, Allium cepa seeds were germinated in soil contaminated with a range of concentrations of eprinomectin: from 0.5 to 62.5 μg/g for the genotoxicity test and from 0.5 to 128.0 μg/g for the phytotoxicity test. The results showed that seed germination was not affected, but root development was affected at concentrations of 0.5 μg/g, 1.0 μg/g, 4.0 μg/g, 8.0 μg/g, 64.0 μg/g, and 128.0 μg/g, and germination speed was significantly changed at concentrations of 1.0 μg/g, 4.0 μg/g, 16.0 μg/g, 32.0 μg/g, and 64.0 μg/g. Significant differences in the mitotic index and genotoxicity index were observed only at concentrations of 2.5 μg/g and 12.5 μg/g, respectively. Only the 0.5 μg/g concentration did not show significant induction of micronuclei in the meristematic cells, but the damage observed at other concentrations did not persist in F1 cells. According to the results, eprinomectin is both phytotoxic and genotoxic, so the release of eprinomectin into the environment should be minimized.

EFFECT OF THE PEEL EXTRACTS FROM TWO CAMPOMANESIA (MYRTACEAE) SPECIES ON ALLIUM CEPA L. (AMARYLLIDACEAE)

Species from the genus Campomanesia have been studied due to their biological activity and low toxicity. However, studies on the fruit peel of these species are scarce. In this context, the effects of ethanol extract from the fruit peel of Campomanesia sessiliflora (O. Berg) Mattos (CS) and Campomanesia guazumifolia (Cambess) O. Berg (CG) were evaluated concerning the effect on germination and meristem cells of roots of Allium cepa. The CG ethanolic extract showed flavonoid compounds higher than CS ethanolic extract. The CS extract showed no antioxidant activity. CS showed greater antiproliferative activity with reduced root size in A. cepa seeds. The two extracts did not induce mutagenicity and cell death at the studied concentration of 1 mg mL-1. Keywords: Germination, Allelopathy, Ethanolic extract.

Influence of the methanol extract and fractions of Smilax brasiliensis Sprengel on development in vitro of Nicotiana tabacum and Alllium cepa

Smilax brasiliensis (Smilacaceae) is a native Brazilian plant found in the Cerrado biome and commonly used in folk medicine. The aim of this study was to evaluate the influence of the methanol extract and fractions from S. brasiliensis leaves on development in vitro of Nicotiana tabacum (tobacco) and Allium cepa (onion) seeds. In vitro germination protocol of onion seeds was established. Tobacco and onion seeds were placed to germinate on basal medium added of extract or fractions of S. brasiliensis leaves and dichlorophenoxyacetic acid (2,4-D), 6-benzylaminopurine (BAP) and gibberellic acid (GA) at different concentrations in the presence of light. The germination ranged from 40 to 100% for tobacco and from 60 to 100% for onion seeds. The results indicated that the extract and fractions promoted higher growth than 2,4-D and GA when analyzed number of nodes, leaves, root and root size for germinated tobacco seeds, and higher growth when analyzed number roots and stem size for onion seeds. Regarding BAP, the extract and fractions inhibited leaf growth, root and root size of tobacco seeds. Further studies are needed to evaluate the possible use of the methanol extract and fractions from S. brasiliensis leaves as natural sources of hormones and/or bioherbicides.

Evaluation of genotoxic and cytotoxic effects of Glyphosate on Allium cepa

Glyphosate is a broad-spectrum herbicide used mostly in crops. This study looked at the genotoxic and Glyphosate has a cytotoxic effect on Allium cepa. As toxicity markers, the Mitotic index, chromosomal aberrations, formations of Micronucleus, germination percentage, root duration, and seed weight were used. Allium cepa seeds were afflicted with distinct concentrations (0.5, 1.0, 2.0 and 4.0 ml/l) of Glyphosate for 24 h treatment periods. The results reveal that pesticide Glyphosateis capable to reduce root growth and causes chromosomal aberrations;consisting of an anaphase bridge, ring chromosome, binucleated cells, multipolarity, Fragment chromosome, vagrant chromosome, chromatid gaps, star anaphase. With increasing Glyphosate concentration, the mitotic index decreased rapidly. In conclusion, our findings indicate that used pesticidemay be toxic to living organism.

Allelopathy, toxicity and phytochemical profile of aqueous extracts from Aspidosperma pyrifolium and Combretum leprosum

This study characterizes the allelopathic effect in the germination of Allium cepa seeds, and toxic on the species Artemia salina, of aqueous extracts of leaves of Aspidosperma pyrifolium and Combretum leprosum and the constituent phytochemical compositions. For this, Allium cepa seeds were germinated in systems containing aqueous extracts (200, 400 and 800 mg.L-1) and distilled water, to evaluate aspects of germination, mitotic phases, mitotic index and limit value of cytotoxicity. The toxicity of the aqueous extracts was evaluated in Artemia salina. The extracts were evaluated qualitatively and quantitatively when the substances present to define the phytochemical profile. The aqueous extract of A. pyrifolium negatively affects the germination process in the hypocotyl and seedling growth at 800 mg.L-1. The LC50 found for the aqueous extract of A. pyrifolium was 4986 mg.L-1. The effect of C. leprosum extract on germination resulted in an increase in the dry matter of the root at 400 mg.L-1 and in the density of the dry matter of the root at 800 mg.L-1. In addition, it reduces the seedling matter at 200 mg.L-1, corresponding to the trend observed in the mitotic index, in which this concentration presented a sublethal score for the limit value of cytotoxicity. The maximum concentration evaluated was not sufficient to determine an LC50 in A. salina. The phytochemical profiles of both species demonstrated classes of substances with potential pharmacological application. This information is important because these species are commonly used as food for farm animals and for purposes in folk medicine.

Developing a biosurfactant to attenuate arsenic contamination in mining tailings

The present study aimed to investigate the ability of a microbial consortium to produce biosurfactant in the presence of two carbon sources and also to evaluate the efficiency of the cell-free supernatant cultures to mobilize As from naturally contaminated soil. Pseudomonas and Stenotrophomonas were the main microorganisms in the microbial consortium. The pH, the incubation time, the temperature, and the glucose and glycerol ratios in the culture medium are the main factors influencing biosurfactant production. The lowest surface tension, 30 mN.m−1, and the higher emulsification index, 58%, were achieved at the optimum production conditions (OPC), i.e., pH 9.5, a 2.5 glucose/glycerol ratio, after three days of incubation at 25 °C. The cell-free extracts containing biosurfactants were more efficient in mobilizing As than distilled water, CaCl2 0.1 mol.L−1; saponin, 0.1%; or sodium dodecyl sulfate, 1% during a sequential soil-flushing procedure. The As mobilization using the supernatants containing biosurfactant was sensitive to pH. The use of OPC cell-free supernatant under alkaline conditions leads to the best-obtained results: 24.6% of As removal (678 mg.kg−1) during sequential extractions. The toxicity reduction of the column eluted solution from the first to the seventh cycle evaluated by the germination index (GI) and morphological structures of Allium cepa in the ecotoxicological assessment confirmed the efficiency of the proposed treatment. Allium cepa seeds and seedlings were sensitive in detecting As in soil and eluted solutions with short time responses to the contaminant. Seeds development increased gradually with arsenic removal. The germination index rose from 0 to 55% after soil decontamination through the proposed soil-flushing procedure.

Toxicity of the sawdust used for phosphorus recovery in a eutrophic reservoir: experiments with Lactuca sativa and Allium cepa.

Eutrophication is one of the environmental problems arising from the increase of essential nutrient concentrations, mainly phosphorus and nitrogen. In contrast to excess phosphorus, the depletion of phosphate rock deposits used for the production of fertilizers compromises the food supply. Therefore, the development of technologies that propose the recovery of the phosphorus contained in eutrophic environments for its later use for agricultural fertilization purposes is very important to ensure global food security. This work aimed to evaluate the toxic potential of the sawdust (biosorbent previously used for phosphorus adsorption) in order to enable its application in agriculture. For this, toxicity experiments with Lactuca sativa (lettuce) and Allium cepa (onion) seeds were performed. The phytotoxic potential was assessed by means of the seed germination index and physiological parameters such as radicle and hypocotyl growth. Cytotoxicity, genotoxicity, and mutagenicity tests were also performed on onion seeds. From statistical tests, it was possible to affirm that the sawdust did not promote inhibition of seed germination and radicle and hypocotyl growth. No genotoxicity, cytotoxicity and, mutagenicity were observed, which allowed to state that the sawdust is not toxic to the onion species, which reinforces the possibility of application of the biosorbent for soil fertilization purposes. Therefore, the use of sawdust for phosphorus biosorption with the subsequent agricultural application is promising and quite important from a global food security point of view.

Influence of the seasons on the water quality of the Marmeleiro River (Paraná, Brazil) using different bioindicators

The use of environmental bioindicators and biomarkers has shown promising to evaluate water quality. In this study, the biological indicators Lactuca sativa L., Allium cepa L., and Artemia salina L. were used to verify the water quality of the Marmeleiro River (Parana, Brazil). Water samples were collected at six points along the river, covering urban and rural areas over the four seasons. The experiment of germination and initial growth of the A. cepa seeds showed changes between seasons, but no difference between the collection points. Regarding L. sativa seeds, the results showed changes between the points and the seasons. In general, it was possible to correlate the highest numbers of germinated seeds, size of the germinated roots, percentage, and germination speed with the highest levels of phosphorus and lowest levels of chemical demand for oxygen, oils and greases, and total solids. The results of the cytotoxicity test with A. cepa showed an increase in the mitotic indices of Points 3 (spring, summer, and winter), 4 (spring and winter), 5, and 6 (summer and autumn) correlated with higher levels of phosphorus and chemical oxygen demand in water samples. For the immobility/mortality test with A. salina, in the spring and summer, all collection points were toxic, possibly due to the lower levels of dissolved oxygen in these samples. Therefore, bioindicators proved to be efficient to determine and monitor the Marmeleiro River toxicity and indicate that preservation actions should be implemented for this watershed.

Cytogenetical and Physiological Effects of L-tryptophan in Onion (Allium cepa L.) Exposed to Salt Stress

In this study, 10 mg L–1 L-tryptophan effects on the seedling growth (fresh weight, radicle length and radicle number), seed germination, chromosomal aberrations and mitotic activity in Allium cepa L. germinated in salinity (0.175 M NaCl) conditions were investigated. In only L-tryptophan medium, the radicle length and radicle number of the seedlings were partially reduced compared to the control seedlings grown in the pure water medium, the germination percentage and fresh weight indicate statistically the same values as the control. Moreover, the chromosomal aberrations and mitotic index in the root tip meristem cells of Allium cepa seeds germinated in alone L-tryptophan medium showed increase compared to the control seeds germinated in the pure water medium. On the other hand, salt stress significantly inhibited the germination rate, radicle length, radicle number and fresh weight of Allium cepa L. In addition, it important reduced the mitotic index (activity) and increased the chromosomal aberrations in root tip meristems of the seeds. Nevertheless, the inhibitory effects of salt stress on all the mentioned parameters were dramatically alleviated by L-tryptophan application. The germination percentage, radicle length, radicle number, fresh weight, mitotic index and chromosomal aberrations of the seedlings grown in 0.175 M salinity were 23%, 10.3 mm, 12.7, 7 g, 1.2 and 17% respectively, while these values became 77%, 15.3 mm, 16.7, 15.2 g, 11.6 and 14.6% in the seedlings treated with 10 mg L–1 L-tryptophan.

Phytochemical screening and evaluation of phytotoxic activity of Solanum lycocarpum (Solanaceae) ripe fruit

The Solanum lycocarpum species, belonging to the Solanaceae family, is popularly known as the wolf fruit and is used in folk medicine for the treatment of obesity, diabetes, and cholesterol reduction. Thus, the aim of this study was to perform phytochemical screening of the ethanol extract from the ripe fruit of S. lycocarpum to verify the presence of the main groups of secondary metabolites and to evaluate the phytotoxic effect on Lactuca sativa (lettuce) and Allium cepa (onion) seeds. The fruits of S. lycocarpum were collected, crushed and percolated with anhydrous ethanol and the solvent was dried in a rotatory evaporator to obtain the ethanol extract. In the phytotoxicity evaluation, the results showed that the ethanol extract was able to completely inhibit the growth of hypocotyl and radicle of L. sativa (lettuce) seeds in all concentrations tested. In A. cepa (onion) seeds, a concentration of 500 μg per plate was able to inhibit the growth of the hypocotyl and radicle by 100%. The metabolites detected in the extract were alkaloids, coumarins, flavonoids, and condensed tannins. The phytotoxic activity can be correlated to the presence of these compounds.

Cytogenetic and Physiologic Efficacies of Grape Seed Extract in Allium cepa L. Seeds Exposed to Salinity

In this study, effects of grape seed extract (GSE) on the seedling growth (fresh weight, radicle length, radicle number), seed germination, mitotic activity, chromosomal aberrations (CAs) and micronucleus frequency (MN) in Allium cepa L. seeds germinated in both saline and normal conditions investigated. In only GSE medium, althought the radicle number and radicle length of seeds partially reduced compared to the control seeds germinated in distilled water medium, the fresh weight partly ascended and germination percentage indicate statistically the same value as the control. Besides, whereas the mitotic index in root-tip meristems of A. cepa seeds germinated in alone GSE medium showed increase compared to the control seeds, CA and MN showed statistically the same values compared to the control. On the other hand, salt stress significantly inhibited the seedling growth and seed germination of A. cepa. What’s more, it reduced significantly the mitotic index in root-tip meristems of the seeds and escalated the number of CA and MN, which is the simplest indicator and the most effective of cytological damage. Contrariwise, inhibitive effects of salt on the mitotic activity, seedling growth, seed germination and CA significantly decreased with application of GSE but, GSE was inefficient in reducing of salt damage on MN.

Cytogenetical and Physiological Effects of β-alanine Treatment in Alleviation of Salt-Induced Stress in Allium cepa L.

In this study, β-alanine effects on the seedling growth (radicle number, radicle length and fresh weight), seed germination, chromosomal aberrations, mitotic activity and micronucleus frequency in Allium cepa L. germinated in both salt stress and normal conditions investigated. In only β-alanine medium, the fresh weight, radicle number and radicle length of the seeds partially reduced compared to the control seeds germinated in distilled water medium but the germination percentage indicate statistically the same value ​​as the control. Besides, while the micronucleus formation and mitotic index in root tip meristems of A. cepa seeds germinated in alone β-alanine medium showed the same values as the control seeds germinated in distilled water medium, the chromosomal abnormalities exhibited an increase compared to the control. On the other hand, salt stress significantly inhibited the seedling growth and seed germination of A. cepa. What’s more, it majorly reduced the mitotic index in meristem cells of the seeds and increased the number of chromosomal abnormalities and micronuclei formation, which is the simplest indicator and the most effective of cytological damage. Althought the harmful affects of saltness on the chromosomal aberrations, seed germination, seedling growth and mitotic activity alleviated in varying degrees by β-alanine treatment, this application was inefficient in damage reducing of salt on the micronucleus formation.

PHYTOCHEMICAL ANALYSIS AND EVALUATION OF THE PHYTOTOXIC EFFECT OF THE HEXANE FRACTION FROM THE LEAVES OF Smilax brasiliensis (SMILACACEAE)

The species of Smilax genus are known as sarsaparilla or japecanga, being widely used in folk medicine as a tonic, antirheumatic, anti-syphilitic, antihypertensive and diuretic and for sweating, arthritis and skin conditions. Thus, the aim of this study was to evaluate the phytotoxic activity and to identify the main classes of secondary metabolites present in the hexane fraction obtained from Smilax brasiliensis. The leaves were collected, dried, crushed and extracted by percolation with ethanol, obtaining the ethanol extract. Part of this extract was partitioned with hexane, resulting in the hexane (HEX) fraction. The best results by the phytotoxic activity in Lactuca sativa seeds were for the HEX4 and HEX5 sub-fractions, at concentration of 250 µg per plate. When evaluating the phytotoxicity in Allium cepa seeds, the best results were found for the HEX1 sub-fraction for the radicle and the HEX2 sub-fraction for the hypocotyl, both at concentration of 125 µg per plate. Phytochemical analysis revealed the presence of coumarins, steroids and flavonoids in the hexane fraction, suggesting that the phytotoxic activity may be attributed at least partially to these compounds; however, additional studies are needed. These results suggest that in the future, the hexane fraction of S. brasiliensis leaves can be used as a natural herbicide.

Effluent from Citrus Industry: Toxic Parameters of Orange Vinasse

Brazil is one of the greatest producers of orange and its orange juice processing industry produces large volumes of solid and liquid waste daily. As an efficient use of the residues from citrus industry, production of bioethanol is highlighted. However, the generation of bioethanol produces a liquid effluent as a by-product, known as vinasse. The objective of this study was to evaluate the toxicity of an effluent from citrus industries, orange vinasse, when applied to soil using Allium cepa seeds. The evaluation was performed by means of germination, root growth, and genotoxic and mutagenic parameters. The EC50 (effectiveness concentration) and ½ EC50, defined in the germination test, were used for genotoxicity tests. Toxicity was observed in dilutions above 40%, which was responsible for reducing the germination speed index. Genotoxicity was observed only using the EC50 and mutagenicity was not detected. According to the results, orange vinasse showed toxicity similar to the sugar cane vinasse, so caution is suggested in the disposal of this effluent into the environment.