Inactivation of isolated fungi on Erythrina velutina Willd. seeds through atmospheric plasma

This study aimed to evaluate the effect of atmospheric plasma application on the inactivation of fungi on the surface of Erythrina velutina seeds and on isolated fungal colonies. Two experiments were conducted using a completely randomized design. First, plasma was applied to the surface of the seeds using helium gas and atmospheric plasma for 3, 6, and 9 min in addition to the control (untreated seeds), constituting seven treatments with five repetitions each. In the second experiment, Petri dishes containing the inoculum of different fungi were treated with atmospheric air plasma for 3, 6, and 9 min (Air-3, Air-6, and Air-9) and were compared with untreated fungi in Petri dishes without treatment (control), totaling four treatments and five repetitions each. We found that the application of atmospheric air plasma to E. velutina seeds for 9 min had an antimicrobial effect on the fungi Aspergillus niger, Aspergillus flavus, Fusarium sp., Brachysporium sp., and Rhizopus sp. The formation of fungal colonies isolated from E. velutina seeds was also inhibited by 3 min of exposure to atmospheric air plasma, except for A. niger, whose inhibition occurred after 6 min of exposure to atmospheric plasma.

Influence of iron nanoparticles (Fe3O4 and Fe2O3) on the growth, photosynthesis and antioxidant balance of wheat plants (Triticum aestivum)

More and more attention is paid to the development of technologies using iron nanoparticles in agriculture. In this regard, the effect of treatment of wheat seeds with various concentrations of iron nanoparticles Fe3O4 and Fe2O3 on the accumulation of biomass, the rate of photosynthesis and respiration, as well as on photochemical activity and antioxidant balance was studied. The seeds were treated for 3 h, germinated for 2 days in Petri dishes, transplanted into sand and grown under light for 18 days without mineral nutrition until the third leaf appeared. At a Fe3O4 concentration of 200 mg L-1 a significant increase in the dry biomass of the second leaf by 45% and the rate of photosynthesis by 16% was observed. At a concentration of nanoparticles in the form of Fe2O3 of 200 and 500 mg L-1, an increase in the rate of photosynthesis in the second leaf was also observed, but not in the biomass of the leaves. The activity of photosystem 2, estimated from the Fv/Fm value, also increased in experiments with nanoiron. However, the activity of antioxidant enzymes, guaiacol-dependent peroxidase and superoxide dismutase, decreased. It is assumed that the acceleration of growth at an early stage of wheat development is associated with an increase in photosynthetic processes.

High dilutions of Magonia pubescens hidrogel affect germination variables in Sorghum bicolor L. Moench

Introduction: In science homeopathic diseases or physiological disorders are not considered just a result of abiotic and biotic factors, but rather a consequence of loss of organic system homeostasis. Homeopathic science is currently being used efficiently in the control of plagues[1], plant diseases[2], in the increase of medicinal plants’ active principles[3] and in plant metabolism[4,5]. Although actual results, both in the academic and field-level, very little is known about physiological mechanisms action of homeopathic medicine on germination process[6]. This work aims to study the effect of M. pubescens hydrogel, on some physiological variables of sorghum germination (Sorghum bicolor L. Moench). Material and methods: The experiment was conducted at Homeopathy and Plant Physiology of Biology Department at UEM in the period from 04/05/06 to 30/12/06. M. pubescens (tingui) seeds were obtained from the region of Montes Claros - Minas Gerais. The M. pubescens hidrogel was obtained from the external centrals wrappers of 4 dry seeds, after they have been disposed in petri dishes with distilled water for a period of 36 hours of soaking (25oC). The hydrogel mother tincture was prepared according to Manual of Technical Standards for Homeopathic Drugstore[7] 3rd ed (2003), in the proportion of a hidrogel part (5g) to ten parts (50g) of absolute alcohol 70% and stored in a glass amber (capped and protected from light). After 15 days of maceration, the solution was filtered and after 48h at rest, the mother tincture was considered ready for use. The dilution 1cH (Centesimal Hahnemannian) was obtained by adding 0.2 ml of the mother tincture in 19.8 ml of distilled water (1/100) and sucussioned 100 times (33 sucussions s-1) by mechanical arm dynamizer with automatic stop (Model Denise 50 - AUTIC). The subsequent dilutions (2cH to 30cH) were obtained from the same procedure, starting from the dilution 1cH. Bioassay: In petri dish containing 15 seeds of sorghum in a circular distributed were added 10 ml with their dilutions (3, 6, 9, 12, 15, 20 and 30cH) and the control containing distilled water. The petri dishes were placed in a growth chamber (type BOD), temperature of (25 ± 2)°C and photoperiod of 16h. The variables were analyzed by germination period of 73.5h as described below: · Germination (%G): %G = (∑ni.N-1)x100 , where ∑ni, is the total number of germinated seeds in relation to the number of seeds put to germinate, expressed in percentage; · Germination average time (GAT): GAT = ∑ni . ti / ∑ni , where ni is the number of germinated seeds within a certain interval of time ti-1 and ti; expressed in hours. · Germination average speed (GAS), expressed in hours): GAS = ∑ni / ∑ni . ti · Germination speed index (GSI): IVG = G1 / N1 + G2 / N2 + ........ Gn / Nn , where G1, G2....Gn is the number of germinated seeds and N1, N2, ... Nn is the number of hours after sowing. The total number of germinated seeds, at each time (12h) was also analyzed. Seeds were considered germinated when the radicle had 1 to 2 mm of lengths. Experimental design: The experimental design was randomized block with 4 replications, totaling 32 experimental units. It was adopted the double-blind methodology, to avoid possible interference or direction by the researcher. Statistical Analysis: The data were analyzed by ANOVA and the averages compared by Scott-Knott test (p≤0.05). The twinning combined data were analyzed for interaction germination x time (G x T) by F test to 5% of probability. Results and discussion: The homeopathy of Magonia pubescens hydrogel affected on the germination kinetic variables of sorghum seeds, when compared with the control (Fig. 1). This effect was most observed in the initial process of germination (from 13h). Research accomplished by Salgado-Labouriau (1973) [8] showed that the hydrogel formed from the external wrapper Magonia pubescens seeds, does not contain inhibiting, but contains factors that accelerate the germination process. Apparently, these results seem contradictory. However, for the homoeopathic optics, some used medicines in a considered way might have determined effect. Already in high diluted doses this behavior can be reversed, as it happens with some drugs. This behavior in pharmacokinetics is denomined Hormesis. When diluted and given dynamism, the product of hydrogel, instead of stimulating, it can delay the germination for the same phenomenon. Hormesis is not yet explained by science. Homeopathy of the Magonia pubescens gel significantly increased the germination average time (GAT) of sorghum seeds and reduced the germination average speed (GAS) and the germination speed index (GSI) (Fig. 2A, B and C). The values of these variables suggest that homeopathy, somehow slowed the speed of sorghum seeds soaking. Conclusion: The results here presented suggest that high dilutions of Magonia pubescens hidrogel can be used in future experiment such as bioherbicide.

Reconfigurable microfluidic circuits for isolating and retrieving cells of interest

Microfluidic devices are widely used in many fields of biology, but a key limitation is that cells are typically surrounded by solid walls, making it hard to access those that exhibit a specific phenotype for further study. Here, we provide a general and flexible solution to this problem that exploits the remarkable properties of microfluidic circuits with fluid walls - transparent interfaces between culture media and an immiscible fluorocarbon that are easily pierced with pipets. We provide two proofs-of-concept in which specific cell sub-populations are isolated and recovered: i) murine macrophages chemotaxing towards complement component 5a, and ii) bacteria (Pseudomonas aeruginosa) in developing biofilms that migrate towards antibiotics. We build circuits in minutes on standard Petri dishes, add cells, pump in laminar streams so molecular diffusion creates attractant gradients, acquire time-lapse images, and isolate desired sub-populations in real-time by building fluid walls around migrating cells with an accuracy of tens of micrometres using 3D-printed adaptors that convert conventional microscopes into wall-building machines. Our method allows live cells of interest to be easily extracted from microfluidic devices for downstream analyses.

High dilutions of acetone affect the Avena sativa growth in vitro

Introduction: Acetone is an organic solvent with molecular structure CH3(CO)CH3, its endogenous production in the animal body is called ketosis. The production of this compound increases with the fat. Acetone influences the lipid membrane, altering its fluidity and lipid composition [1], causing cell damage and leakage and can cause cell death. The use of herbicides in organic farming is not accepted by the Brazilian legislation [2]. So the weed control becomes a problem for organic farmers. The aim of this study is to evaluate the herbicide potential of high dilutions of acetone on Avena sativa L. Materials and Methods: The preliminary tests were conducted at the Laboratory of Plant Physiology and Homeopathy, State University of Maringá (UEM). The seeds of Avena sativa are placed in Petri dishes. Fitty seeds were germinated and grown in Petri dishes containing 15ml of high dilution of acetone and maintained at 25°C ± 2 and 12h photoperiod. Acetone dilutions (6, 12, 18, 24 and 30cH) were obtained according to the Brazilian Homeopathic Pharmacopoeia [3]. Were evaluated the shoot length (cm), total length (cm), fresh root (mg) and total dry mass (mg). The plants growth was measured after 7 days. The control consisted of distilled water. The experiment evaluated 4 replicates of each treatment and the data were analyzed by ANOVA and means were compared by Scott-Knott test (P ≤ 0.05). Results and Discussion: Dilutions 6, 24 and 30 cH inhibited the growth of the shoot and total seedling of A. sativa. The root fresh weight was significantly reduced by 4 dilutions (6,12,24 and 30x), with no difference of 24x compared to the control. The total dry mass of plants of A. sativa was reduced in all the dilutions studied, showing an inhibitory effect on growth of seedlings subjected to treatment. Somehow, acetone diluited inhibited the growth and accumulation of biomass of these seedlings, suggesting an imbalance in metabolism that resulted in a reduction in the variables values. Conclusion: The results suggest that high dilutions acetone interfere on the growth and accumulation of biomass of A. sativa.

In vitro behavior of Mycoplasmagallisepticum live-type nosode

As a step of a doctoral research project, in this study a live-type nosode was prepared from microorganism Mycoplasmagallisepticum strain R (ATCC 93-08/19610) according to Costa model and the rules by Brazilian Homeopathic Pharmacopoeia. Live nosode was tested in vitro to assess safety when used to immunize domestic fowl (Gallus gallus) against infection by this microorganism and to investigate its behavior under laboratory conditions. M. gallisepticum was not shown to grow in fluid (broth) and solid (plate) modified Frey medium with dilutions 11d, 12d, 20d and 30d. Inhibition halos about 2.0 mm were observed around paper disks impregnated with live-type nosode in microorganism-sown Petri dishes, whereas disks impregnated with conventional antibiotic oxytetracycline exhibited 8.0 mm inhibition halos. Protein assessment by Folin-Lowry method showed protein absence in dilutions 12d and 30d and neither microbial DNA traces were found in PCR assay in dilutions 12d, 20d and 30d.

PROPUESTA DE UNA METODOLOGÍA PARA CUANTIFICAR LA ACTIVIDAD ANTIBACTERIANA DE LA MIEL

In this study a standardized method for objectively comparing the antibacterial activity of honey was developed. The assay was performed using a strain of S. aureus and four honeys that have been shown antibacterial activity against this strain. The antibacterial activity of honeys were checked by using an agar plate diffusion method using S. aureus (ATCC 29213) as the test organism. On the surface of each agar plate six stainless steel cylinders with a diameter of 8,14 mm were radially disposed. Onto each cylinder 0,1 mL of sample honey at 10% v/v was placed and all Petri dishes were incubated at 35°C during 24 h. Each sample were analyzed by triplicate. The surface of the cylinder diameter was set as reference antibacterial activity equivalent to minimal inhibitory concentration (MIC). The antibacterial activity of each honey was quantitated by the relationship between the surface of the inhibitory zone and the surface of the reference activity expressed as multiples of MIC (x MIC). The method allowed establishing differences between the bacterial activities of the different honeys tested and could be used for identifying honeys that could be employed with medicinal purpose for the treatments of wounds.

The Photograph Registration of Petri Dishes in High Quality and Image Editing of Microbiological Testing

Science is based on evidence that can be measured or observed through methodical techniques which are expressed in several ways, either quantitatively or qualitatively. The technical photograph becomes one of the most important key tools to the result’s disclosure. In the microbiological research, several pieces of evidence can be indicated with variables that are deeply related to the means of culture; pH and color variation, halo formation, overlay of structures, culture shape, among others. The employment of technical photographs, as a strategy of the experimental observation and reliable representation, is indispensable. The protocol presented here suggests the production of the photographic support in microbiological tests runs on Petri dishes, taken by a smartphone to obtain high-quality images, besides showing tools to edit images through PowerPoint. The support is composed of a paper tube with a transparent border, whose reduced light penetration avoids problems, such as the luminous reflection over the Petri dishes or the environment itself. The edition consists of the photograph variation, and in clipping and pasting on uniform backgrounds to provide further detailing. The protocol allowed a standardized photograph collection in high quality, which is ideal for a comparative portrait of microbiological behaviors. The image editing enabled a framework and greater visibility of physical and biological structures in the exhibition of photographs inside the manuscript, such as the removal of noises, background alterations, deformities or irregularities. This protocol is a tool that helps the researcher on the knowledge-obtaining process, and it is applied to different experiments or adapted into the most variable research subjects.

Lessons Learned from the Studies of Roots Shaded from Direct Root Illumination

The root is the below-ground organ of a plant, and it has evolved multiple signaling pathways that allow adaptation of architecture, growth rate, and direction to an ever-changing environment. Roots grow along the gravitropic vector towards beneficial areas in the soil to provide the plant with proper nutrients to ensure its survival and productivity. In addition, roots have developed escape mechanisms to avoid adverse environments, which include direct illumination. Standard laboratory growth conditions for basic research of plant development and stress adaptation include growing seedlings in Petri dishes on medium with roots exposed to light. Several studies have shown that direct illumination of roots alters their morphology, cellular and biochemical responses, which results in reduced nutrient uptake and adaptability upon additive stress stimuli. In this review, we summarize recent methods that allow the study of shaded roots under controlled laboratory conditions and discuss the observed changes in the results depending on the root illumination status.

Is the South-Mediterranean Canopy-Forming Ericaria giacconei (= Cystoseira hyblaea) a Loser From Ocean Warming?

Canopy-forming brown algae support highly productive ecosystems whose decline has been attributed to the interplay of several anthropogenic disturbances. Climate change could have disruptive effects on the biology of these species, but the role of temperature in the development of early life stages is poorly understood. The aim of this study was to assess the response of Ericaria giacconei, a winter-reproducing Southern–Mediterranean endemic species, to thermal stress by testing five temperatures (12, 15, 18, 24, and 28°C) on adults and early stages. Chlorophyll a fluorescence of adult plants was measured at 0, 24, 72, and 120 h on nine fronds in each of the three aquaria per treatment. To assess egg release, zygote settlement, and embryo growth rate, approximately 1,200 receptacles were cultured on six Petri dishes per temperature treatment, and 10 random subsections of 2 ×2 mm were examined in three Petri dishes at 0, 20, 44, and 92 h after fertilization. Adult plants showed a plastic physiological response, and thermal stress had no significant effect on PSII efficiency. Embryos fully developed only at 12 and 15°C. Mortality increased at 18 and 24°C, and no zygotes survived at 28°C. In a scenario of further increasing temperatures, the effects of warming could affect the recruitment of E. giacconei and increase its vulnerability to further stresses. These effects on the survival of early stages, which are the bottleneck for the long-term survival of the species, should be taken into account in conservation and restoration measures to maintain canopy-forming macroalgal populations and associated biodiversity and ecosystem services.