Mitigating salt stress by conditioning seeds with ultraviolet light (UV-C) in white oats (Avena sativa L.).

Seed conditioning with ultraviolet light (UV-C) might (1) improve crop yield and quality, (2) reduce the use of agrochemicals during cultivation, and (3) increase plant survival in high salinity environments. The aim of this study was to examine the effects of UV-C conditioning of white oat seeds at two doses (0.85 and 3.42 kJ m-2) under salinity stress (100 mM NaCl). Seeds were sown on germination paper and kept in a germination chamber at 20°C. Germination and seedling growth parameters were evaluated after 5 and 10 days. Data demonstrated that excess salt reduced germination and initial growth of white oat seedlings. In all the variables analyzed, exposure of seeds to UV-C under salt stress exerted a positive effect compared to non-irradiated control. The attenuating influence of UV-C in germination was greater at 0.85 than at 3.42 kJ m-2. Thus, data indicate that conditioning white oat seeds in UV-C light produced greater tolerance to salt stress. These findings suggest that UV-C conditioning of white oat seeds may be considered as a simple and economical strategy to alleviate salt-induced stress.

Influence of Limosilactobacillus fermentum IAL 4541 and Wickerhamomyces anomalus IAL 4533 on the growth of spoilage fungi in bakery products.

Fungi are the main microorganisms responsible for the spoilage of bakery products, and their control and subsequent reduction of food waste are significant concerns in the agri-food industry. Synthetic preservatives are still the most used compounds to reduce bakery product spoilage. On the other hand, studies have shown that biopreservation can be an attractive approach to overcoming food and feed spoilage and increasing their shelf-life. However, limited studies show the preservation effects on real food matrices. Therefore, this study aimed to investigate the influence of microorganisms such as lactic acid bacteria (LAB) and yeasts on the growth of spoilage filamentous fungi (molds) on bread and panettones. In general, on conventional and multigrain bread, treatments containing Limosilactobacillus fermentum IAL 4541 and Wickerhamomyces anomalus IAL 4533 showed similar results when compared to the negative control (calcium propionate) in delaying the fungal growth of the tested species (Aspergillus chevalieri, Aspergillus montevidensis, and Penicillium roqueforti). Different from bread, treatments with W. anomallus in panettones delayed the A. chevalieri growth up to 30 days, 13 days longer than observed on negative control (without preservatives). This study showed that biopreservation is a promising method that can extend bakery products' shelf-life and be used as an alternative to synthetic preservatives.

Graphene oxide decreases the effects of salt stress on Persian clover seed germination.

Among biotic and abiotic stresses, the most restrictive for plant distribution is salt stress, where different concentrations might exert harmful effects on seed germination. Recently, nanomaterials were used successfully to mitigate these stresses, indicating that plants may be able to develop normally in adverse conditions. The aim of this study was to examine the effects of graphene oxide (GO) on the germination of Persian clover seedlings under salt stress conditions. Following sown on substrate paper, seeds were tested after exposure to different concentrations of graphene oxide (0, 125, 250, or 500 mg L-1 GO), sodium chloride (0; -0.1; -0.2; -0.3, or -0.4 MPa NaCl) and/or GO + salt concomitantly, and then stored for 7 days in a germination chamber at 20°C in the presence of light. Seed germination and growth parameters of seedlings were determined. Graphene oxide demonstrated protective effect against salt stress as evident by no marked adverse effects on seed germination where GO blocked the salt-induced reduction in germination. The results obtained provide references for the safe application of nanomaterials and emphasize the significance of GO as a promising material for reducing the toxicity of salts in agriculture.

Seed germination of Hesperozygis ringens (Benth. ) Epling, an endemic and threatened species

Hesperozygis ringens (Lamiaceae), popularly known as espanta-pulga, is a threatened species endemic to rocky and sandy regions of the Pampa biome. One factor that can influence the low number of individuals of a species is a low seed germination rate influenced by temperature and/or light. Thus, the objective of this study was to evaluate the influence of light and temperature on the seed germination of H. ringens. The seeds of two lots were sown on a paper substrate and maintained in BOD chambers at temperatures of 15, 20, 25 and 30ºC in the presence and absence of light. The germination speed rate was evaluated every 3 days for 21 days. The experiment was completely randomized with treatments that had a 4 x 2 factorial design. The first visible sign (protrusion of the primary root) of germination was observed seven days after sowing. Germination occurred both in the presence and absence of light and the lowest temperatures significantly influenced the germination process and germination speed. For germinating the species, 15°C was the most favorable temperature compared to 20, 25 and 30°C. It can be concluded that a temperature of 15ºC favors the germination process of H. ringens seeds, which are insensitive to light.(AU)

Effect of salt stress on germination and initial development of Ruta graveolens L. / Efeito do estresse salino na germinação e desenvolvimento inicial de Ruta graveolens L.

Salinization occurring through irrigation on arable land has been a growing concern worldwide. This study aimed to evaluate the germination and initial development of common rue subjected to different saline concentrations. Two salts (sodium chloride and calcium chloride) and five saline concentrations (zero, -0.1, -0.2, -0.3, and -0.4 MPa) were utilized. Germination tests, first germination count, seedling length and dry weight were employed to assess seed responses to the studied variations. Based on the results, the excess of salt reduces the germination percentage and the initial development of common rue seedlings, regardless of the substance used for stress induction.

A salinização, devido à irrigação em terras cultiváveis, tem sido uma preocupação crescente em todo mundo. Diante disso, objetivou-se com este trabalho avaliar a germinação e o crescimento inicial de arruda submetida a diferentes concentrações salinas. Foram utilizados dois sais (cloreto de sódio e cloreto de cálcio) e cinco concentrações salinas (zero, -0,1; -0,2; -0,3 e -0,4 MPa). As respostas das sementes a essas variações foram avaliadas pelos testes de germinação, primeira contagem de germinação, além do comprimento e massa seca das plântulas. De acordo com os resultados, o excesso de sais reduz a percentagem de germinação e o desenvolvimento inicial das plântulas de arruda, independente da substância utilizada para indução do estresse.

Inoculation of corn seeds with Azospirillum brasilense in different temperatures / Inoculation of corn seeds with Azospirillum brasilense in different temperatures

Growth-promoting bacteria Azospirillum brasilense, used as an inoculant in corn culture, can be severely affected by the exposure temperature, with a lethal effect above 35°C, when cultivated alone under laboratory conditions. Such effects may limit the associative interaction between plant-bacteria, with reduced inoculation efficiency, resulting in a lower growth rate of the plant and an increase in oxidative stress. Thus, the objective of the research was to evaluate the efficiency of the inoculation process with A. brasilense in seeds and in the initial growth of seedlings of two corn cultivars submitted to different temperatures. Were utilized corn hybrids seed Syn 488 and Syn 505. The experimental design was completely randomized in a 2 x 4 factorial scheme (with and without inoculation of A. brasilense x 4 sowing temperatures: 20, 25, 30, and 35ºC), with four replications. The inoculation efficiency in corn seedlings submitted to different temperatures was evaluated through the following tests: germination, first count, seedling length and dry weight. In addition, responses at the biochemical level of the interaction (temperatures x inoculation) for the content of photosynthetic pigments and hydrogen peroxide (H2O2), antioxidant enzymes and lipid peroxidation were evaluated. The inoculation with A. brasilense changed the morphological and biochemical responses of corn see

Growth-promoting bacteria Azospirillum brasilense, used as an inoculant in corn culture, can be severely affected by the exposure temperature, with a lethal effect above 35°C, when cultivated alone under laboratory conditions. Such effects may limit the associative interaction between plant-bacteria, with reduced inoculation efficiency, resulting in a lower growth rate of the plant and an increase in oxidative stress. Thus, the objective of the research was to evaluate the efficiency of the inoculation process with A. brasilense in seeds and in the initial growth of seedlings of two corn cultivars submitted to different temperatures. Were utilized corn hybrids seed Syn 488 and Syn 505. The experimental design was completely randomized in a 2 x 4 factorial scheme (with and without inoculation of A. brasilense x 4 sowing temperatures: 20, 25, 30, and 35ºC), with four replications. The inoculation efficiency in corn seedlings submitted to different temperatures was evaluated through the following tests: germination, first count, seedling length and dry weight. In addition, responses at the biochemical level of the interaction (temperatures x inoculation) for the content of photosynthetic pigments and hydrogen peroxide (H2O2), antioxidant enzymes and lipid peroxidation were evaluated. The inoculation with A. brasilense changed the morphological and biochemical responses of corn see

Stability, sensory attributes and acceptance of panettones elaborated with Lactobacillus fermentum IAL 4541 and Wickerhamomyces anomallus IAL 4533.

This work aimed to elaborate sourdough panettones with Lactobacillus fermentum (LF) and Wickerhamomyces anomallus (WA) evaluating their microbiological stability, physical and chemical characteristics as well as the impact of these microorganisms on sensory aspects and consumer acceptance. For characterization, panettones were elaborated by long fermentation, using two selected microorganisms, LF and WA in different proportions; and control panettones were formulated using commercial yeast with and without preservative. For sensory analyses, LF, WA, LF/WA (1:1), control with calcium propionate and commercial panettones were compared. Regarding the pH values and total titratable acidity (TTA), a similar behavior was observed among panettones elaborated with the selected strains (LF, WA and mixtures). On the other hand, panettones elaborated with commercial yeast showed a higher pH and lower TTA. Until the 112nd day of storage, the water activity (aw) was similar among all panettones, but in the following analyses, it dropped in all panettones. Panettones elaborated with sourdough maintained better their softness during the storage, when compared with the controls. Regarding microbial stability, control panettones with and without preservative became moldy faster; while sourdough panettones (WA and LF/WA) remained stable throughout all the monitored storage. Sensory evaluation by CATA allowed distinguishing between sourdough and commercial yeast panettones. Desirable characteristics such as nice aroma, pleasant taste and uniform color were checked more often for LF and WA elaborated panettones, whereas yeast flavor was checked more often for the Commercial. Moreover, according to the descriptors used, panettones were grouped into 3 groups: LF/WA, LF + WA and controls. The panettones elaborated with the specific microorganisms of this study were well-accepted sensorially, proving to be very competitive with respect to control and commercial panettone. So, the use of selected microorganisms as a starter for sourdough is a promising alternative for producing panettones with good technological quality, microbiological stability, sensorially differentiate and well accepted by consumers; and, additionally, with the appeal of no added preservative.

Survival and stability of Lactobacillus fermentum and Wickerhamomyces anomalus strains upon lyophilisation with different cryoprotectant agents.

The stability of microorganisms along the time is important for allowing their industrial use as starter agents, improving fermentation processes. This study aimed to evaluate the survival and maintenance of the cell viability of the lactic acid bacteria Lactobacillus fermentum IAL 4541 and the yeast Wickerhamomyces anomalus IAL 4533, both isolated from wheat sourdough, after lyophilisation with different cryoprotectant and storage at room temperature along a year. Treatments involved adding control solution (S1 = 0.1% peptone water), and four cryoprotectant solutions S2 (10% sucrose), S3 (5% trehalose), S4 (10% skim milk powder) and S5 (10% skim milk powder plus 5% sodium glutamate) to the microbial cells previously of freeze drying processing. To verify the effect of lyophilisation on the number of microbial cells recovered, microbiological analyses were performed and cell viability was calculated before and after lyophilisation and regularly during a storage period of 365 days at room temperature. Viability after freeze-drying was influenced by the cryoprotectant agent employed, as well the microbial stability conferred along the storage. Differences on the microorganism response to some protectors were observed between the lactic acid bacteria and the yeast evaluated. W. anomalus was more affected by absence of cryoprotectant (S1) during freeze drying processing, but this microorganism was more stable than L. fermentum along the storage without the presence of protectant agents. For L. fermentum, S5 was the best protectant, allowing the recovering of 100% of the bacterial cells after lyophilisation and 87% of cell viability was observed after one year storage, followed by S4 (96 and 74%, respectively). S4 and S5 were the best protectant to W. anomalus (viability >80% after 1 year), but no increase in the yeast cell viability was conferred by addition of glutamate (S5) to skim milk. After 1 year of storage, trehalose was much more effective on protection of the yeast than bacteria (72% and 7% of viability, respectively). S2 was the less protectant agent among the tested, and their effectiveness was higher in L. fermentum (allowing 14% of cell recovering up to 120 days of storage) if compared to W. anomalus (25% of viability until 90 days of storage). Our results demonstrate that freeze-drying is a realistic technology for the stability and maintenance of the potential sourdough starter L. fermentum and W. anomalus for long time; however, the choice of cryoprotectant will influence the process effectiveness.

Cadmium toxicity on seed germination and initial growth of chia

In recent years, there has been a growing concern related to soil and water contamination due to the constant dispersal of toxic metals. In addition to their ecotoxicological potential, these elements exhibit a cumulative character that favors their permanence in soil and passage to living organisms, which can lead to an ecological imbalance. Among toxic metals, cadmium (Cd) is an obstacle to agriculture because it can adversely affect food quality and human health, as well as diminish plant growth and productivity. Thus, the objective of this work was to evaluate the toxicity of cadmium on seed germination and initial growth of chia. The ecotoxicological effects of four Cd concentrations (15; 30; 45; and 60 mg L-1) were evaluated. The response variables were germination percentage, first count, germination speed index, total length, shoot length, root length, seedling dry mass, and tolerance index. It is concluded that the presence and accumulation of Cd in the culture substrate played an inhibitory role in seed germination and initial seedling growth of chia starting at 15 mg L-1. On the other hand, no significant effect was observed for the treatments in relation to dry mass of the chia seedlings.

Determination of cadmium, lead and thallium in highly saline hemodialysis solutions by potentiometric stripping analysis (PSA).

Potentiometric stripping analysis (PSA) was investigated to assay simultaneously cadmium, lead and thallium present as contaminants in highly saline solutions used in hemodialysis. The saline matrices were sodium, potassium, magnesium and calcium chlorides, sodium acetate, sodium bicarbonate and glucose, which constitute concentrates for hemodialysis. A 1000mugmL(-1) Hg(II) solution was used to prepare the mercury film electrode (MFE) and to carry out the stripping step. After a 30s accumulation interval the analytes were simultaneously detected in the saline matrices without using masking agents. Determination limits of 80ngL(-1) for cadmium and thallium, and 50ngL(-1) for lead were calculated and a R.S.D. ranging from 0.5 to 2.2% (n = 3) was obtained measuring the analytes directly in commercial hemodialysis saline solutions. Recoveries from spiked samples ranging from 94.6 to 102.0% were obtained. The investigated metals were found in concentrations ranging from 2.7 to 5.7mugL(-1) for cadmium, 27.7 to 75.8muL(-1) for lead and 9.6 to 18.7mugL(-1) for thallium in commercial hemodialysis solutions. The PSA method showed to be adequate to the quality control of saline concentrates for hemodialysis.

Determination of aluminum as contaminant in dialysis concentrates by adsorptive cathodic stripping voltammetry.

This paper describes a stripping voltammetric method for the determination of aluminum as contaminant in dialysis concentrates. It is based on the adsorptive deposition of the complex Al-1,2-dihydroxyanthraquinone-3-sulfonic acid (DASA) at the hanging mercury drop electrode (HMDE) at -0.9V (versus Ag/AgCl) and its cathodic stripping during the potential scan. The method was optimized concerning the main electrochemical parameters that influence the voltammetric determination in highly saline solutions (sample dilution factor, deposition time and DASA concentration). The linear range for the measurements was from