974 resultados para Cultivated mushroom
Resumo:
Biodegradation of glyphosate was evaluated in rhizospheric soil cultivated with Glycine max (soybean, var. BRS245-RR), Canavalia ensiformis and Stizolobium aterrimum. After these species were cultivated for 60 days, soil samples were collected, placed in flasks and treated with 14C-glyphosate. After 30 days of incubation, the total release rate of C-CO2 was determined along with microbial biomass (MBC), metabolic quotient (qCO2), and degradation percentage of the radio-labeled glyphosate released as 14C-CO2. A higher mass of rhizosphere-associated microorganisms was verified in the soil samples from pots cultivated with soybean, regardless of glyphosate addition. However, in the presence of the herbicide, this characteristic was the most negatively affected. Microorganisms from the C. ensiformis rhizosphere released a lower amount of 14C-CO2, while for those originated from S. aterrimum, the amount released reached 1.3% more than the total carbon derived from the respiratory activity. The rhizospheric soil from S. aterrimum also presented higher glyphosate degradation efficiency per microbial biomass unit. However, considering qCO2, the microbiota of the rhizospheric soil cultivated with soybean was more efficient in herbicide degradation.
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The objective of this study was to evaluate oxadiazon sorption in different soils of the Brazilian Cerrado, highlighting the correlations of lethal doses of this herbicide capable of inhibiting 50% of the dry matter accumulation of the bio-indicator (LD50) among the chemical characteristics of the soil and its direct and indirect effects. The experiment was carried out in a greenhouse in a randomized block design and four repetitions. Each experimental unit consisted of a pot with increasing rates of oxadiazon and oat (Avena sativa), as the bio-indicator species. For sorption evaluation, washed sand and 22 soils (substrates) from Cerrado Brazilian's Alliaceae cultivated areas were used. LD50 and sorption ratio (SR) = [(LD50soil - LD50sand)/LD50sand] to the substrates were determined. Pearson correlation analysis was performed between the chemical characteristics of the substrates and the LD50 of oxadiazon. A path analysis was quantified, to deploy only the significant correlations estimated in direct and indirect effects of the characters on LD50, which is a basic variable. A more pronounced LD50 (528.09 g ha-1) for the Cerrado soil sample resulted in higher SR (> 53.00), while in the washed sand substrate, LD50 corresponded only to 9.74 g ha-1 of the oxadiazon (available in soil). It was concluded that oxadiazon sorption is influenced by the chemical characteristics of the soils, highlighting the correlation with pH (CaCl2), magnesium content, aluminum, organic matter, organic carbon, and aluminum saturation.
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Soil is a very heterogeneous environment that allows the establishment of wide range of microorganisms populations, whose balance is affected by biotic and abiotic factors. This study has aimed to assess the effect of doses of mesotrione and fluazifop-p-butyl herbicides and two assessment periods on microbial activity and biomass of soil cultivated with cassava Cacau-UFV cultivar, besides the root colonization by arbuscular mycorrhizal fungi. Two trials were conducted in a protected environment where was realized post-emergence application of mesotrione in the doses of 72, 108, 144 and 216 g ha-1 and fluazifop-p-butyl in the doses of 100, 150, 200 and 300 g ha-1, besides a control without application. Soil samples were collected for determination of soil respiratory rate (RR), microbial biomass carbon (MBC), metabolic quotient (qCO2), and colonization of roots by arbuscular mycorrhizal fungi at the 30 and 60 days after applications (DAA) of the herbicides. Fluazifop-p-butyl increased the RR, MBC and the percentage of cassava roots colonized by mycorrhizal fungi in the assessment performed at 60 DAA. The larger effects of mesotrione on soil microbial indicators were up to 30 DAA, being the changes minimized at 60 DAA. It is concluded that the herbicides alter the soil microbial indicators, with effects dependent of the product, of dose applied and also of the period of assessment.
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ABSTRACT The increase in the area planted with Crotalaria spectabilishas occurred by several factors, highlighting the potential to reduce the nematodes, nitrogen fixation and the high production of biomass. By becoming a species sown as a crop, it is necessary to control the weeds that coexist with showy crotalaria. This change in the use of this crop creates the possibility of this specie becoming a weed. The aim of this study was to assess the potential use of herbicides applied in preemergence and postemergence of C.spectabilisfor different purposes (control of volunteer and selectivity plants). Three experiments were installed in a greenhouse (two with herbicides applied in preemergence - in soils with distinct textural categories; and one experiment with herbicides applied in postemergence). The results of the experiments with herbicides applied in preemergence showed that: amicarbazone, atrazine, diuron, metribuzin, prometryn, fomesafen and sulfentrazone showed effectiveness for control of C.spectabilis in clayey soil. Besides these, flumioxazin and isoxaflutole also showed potential to be used in the control of showy crotalaria in soils with loam texture. In relation to the postemergence herbicides, atrazine, diuron, prometryn, flumioxazin, fomesafen, lactofen, saflufenacil, amonio-glufosinate and glyphosate can be used aiming the chemical control of C.spectabilis. Herbicides chlorimuron-ethyl, diclosulan, imazethapyr, pyrithiobac-sodium, trifloxysulfuron-sodium, clomazone, pendimethalin, S-metolachlor and trifluralin applied in preemergence, and imazethapyr, pyrithiobac-sodium, flumiclorac, bentazon and clethodim applied in postemergence caused low levels of injury to C.spectabilis plants, making necessary the development of new searches to ensure the selectivity of these products.
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ABSTRACT Understanding the critical period of weed competition is indispensable in the development of an effective weed management program in field crops. Current experiment was planned to evaluate the critical growth period ofSetaria and level of yield losses associated with delay in weeding in rain-fed drip irrigated wheat production system of Saudi Arabia. Field experiment was conducted to evaluate the effect of weeding interval (07-21, 14-28, 21-35, 28-42 and 35-49 days after sowing) and drought stress (75% and 50% of field capacity) on Setaria growth, wheat yield and water use efficiency. Season long weedy check and wellwatered (100% FC) plots were also maintained for comparison. Weeding interval and drought stress significantly (p ≤ 0.05) affected the growth and yield of Setaria and wheat. Drought stress from 75% to 50% FC resulted in reductions of 29-40% in Setaria height, 14-27% in Setaria density and 11-26% in Setaria dry biomass. All weeding intervals except 35-49 DAS significantly suppressedSetaria growth as compared with control. Delay in weeding increased weed-crop competition interval and reduced wheat yield and yield contributors. Therefore, the lowest yield of 1836 kg ha-1 was attained for weeding interval of 35-49 DAS at 50% FC. Water use efficiency and harvest index increased with decreasing FC levels but reduced with delay in weeding. Correlation analysis predicted negative association ofSetariadensity with wheat yield and yield contributors and the highest negative association was for harvest index (-0.913) and water use efficiency (-0.614). Early management of Setaria is imperative for successful wheat production otherwise yield losses are beyond economical limits.
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The present work characterized and compared the anatomical structures of the leaves of Bactris gasipaes (Arecaceae) plants grown under different cultivation conditions (in vitro, ex vitro and in vivo) with the goal of identifying the origins of the difficulties encountered in acclimatizing micro-plants. The Quant program was used to determine leaf tissue thicknesses and areas, and histochemical tests were performed on leaf sections and analyzed using light microscopy. Stomatal and trichome densities were determined using the epidermal impression method and by scanning electronic microscopy. Our results indicated that there were no discernible alterations of the anatomical characteristics of the leaves of micro-plants cultivated under differing conditions and that the thickening of the mesophyll and the vascular fibers indicated adaptive responses to ex vitro conditions. As such, the observed difficulties in acclimatizing peach palm micro-plants to ex vitro conditions cannot be attributed to plant anatomical characteristics acquired during in vitro cultivation.
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Sixty Piaractus mesopotamicus Holmberg, 1887 (pacu) fry fed a diet containing 0, 50, 100 and 200 mg ascorbic acid/kg dry feed were studied to evaluate the effect on parasitic infestation by the monogenean Anacanthorus penilabiatus Boeger, Husak and Martins, 1995 (Monogenea: Dactylogyridae) for a period of 24 weeks. The temperature of the aquaria was measured daily and remained between 28 and 31oC. At the beginning of the experiment, fish showed 6.15 ± 0.33 cm standard length and 8.64 ± 1.62 g average body weight. A sample of fish was examined and showed 43 ± 17 monogeneans per fish. At the end of the experiment, the gills of control and vitamin C-treated fish were collected for parasite counts. Control fish had 42.5 parasites per fish, a significantly higher number (P<0.05) when compared with fish fed vitamin C, that showed 16.5 parasites per fish. Ascorbic acid fortification in the food promoted an increase in fish resistance to parasites. It is suggested that an optimum level of 139 mg/kg vitamin C supplementation either elicited better nutritional conditions by stimulating the appetite of the fish or improved the immune response.
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Agaricus blazei Murill is a native Brazilian mushroom which functions primarily as an anticancer substance in transplanted mouse tumors. However, the mechanism underlying this function of A. blazei Murill remains obscure. The present study was carried out to investigate the effect of fraction FA-2-b-ß, an RNA-protein complex isolated from A. blazei Murill, on human leukemia HL-60 cells in vitro. Typical apoptotic characteristics were determined by morphological methods using DNA agarose gel electrophoresis and flow cytometry. The growth suppressive effect of fraction FA-2-b-ß on HL-60 cells in vitro occurred in a dose- (5-80 µg/mL) and time-dependent (24-96 h) manner. The proliferation of HL-60 cells (1 x 10(5) cells/mL) treated with 40 µg/mL of fraction FA-2-b-ß for 24-96 h and with 5-80 µg/mL for 96 h resulted in inhibitory rates ranging from 8 to 54.5%, and from 4.9 to 86.3%, respectively. Both telomerase activity determined by TRAP-ELISA and mRNA expression of the caspase-3 gene detected by RT-PCR were increased in HL-60 cells during fraction FA-2-b-ß treatment. The rate of apoptosis correlated negatively with the decrease of telomerase activity (r = 0.926, P < 0.05), but correlated positively with caspase-3 mRNA expression (r = 0.926, P < 0.05). These data show that fraction FA-2-b-ß can induce HL-60 cell apoptosis and that the combined effect of down-regulation of telomerase activity and up-regulation of mRNA expression of the caspase-3 gene could be the primary mechanism of induction of apoptosis. These findings provide strong evidence that fraction FA-2-b-ß could be of interest for the clinical treatment of acute leukemia.
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In this study, folates were evaluated in the main species of mushroom cultivated in Brazil. The species analysed were Agaricus bisporus (button mushroom), Lentinula edodes (shiitake) and Pleorotus ostreatus (shimeji). The five main forms of folate found in foods were determined: tetrahydrofolic acid (THFA), 10-methyl folic acid (10MFA), 5-methyl tetrahydrofolic acid (5MTHFA), 10-formyl folic acid (10FFA) and 5-formy tetrahydrofolic acid (5FTHFA). The methodology employed used extraction with phosphate buffer, clean up with trichloroacetic acid and separation of the vitamins by high-performance liquid chromatography, with simultaneous ultraviolet and fluorescence detection. The results obtained for total folate were 551 to 1404 µg.100 g -1 for the button mushroom, 606 to 727 µg.100 g -1 for shiitake and 460 to 1325 µg.100 g-1 for shimeji. The data showed that mushrooms could be considered as sources of folates and that their contribution of these vitamins to the diet was meaningful.
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Aiming at improving the quality of Perna perna mussels cultivated and commercialized in Ubatuba, SP, Brazil, the growth and elimination of Staphylococcus aureus and Bacillus cereus artificially inoculated in mussels were studied. The inoculation was carried out in "in natura" and pre-cooked mussels for 30 min, and after that the mussels were kept for 10 hours at room temperature (25 ± 1 °C) and under refrigeration (7 ± 1 °C). Six thermal treatments were evaluated: three using steam (5, 10 and 15 minutes) and three in boiling water (5, 10 and 15 minutes), in order to find the best time/temperature binomial to provide pathogenic control. Yield and physical-chemical and sensory characteristics were evaluated. All thermal treatments were efficient to eliminate microorganisms in 2 logarithmic cycles. However, the boiling water treatments presented better results than the steam treatments. The physical-chemical and sensory analyses did not show statistical differences among the thermal treatments studied. The best performances were reached in the shortest times of heat exposure. Overall, the treatments in boiling water presented better results than the steam treatments.
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The artisanal production of cachaça, a beverage obtained by the fermentation of sugar cane juice after distillation, especially by small-sized producers, has traditionally used natural ferment ("fermento caipira") which consists of sugar cane juice with crushed corn, powdered rice, or citrus fruits. In despite of the difficulties in quality control due to the high level of contaminants and longer periods of preparation, the sensorial quality of the beverage may be attributed to the physiological activities of wild yeasts and even bacteria present during fermentation when this ferment is used. In this context, the aim here was to evaluate the microbiological (yeasts) and physicochemical characteristics of sugar cane juice extracted from different parts of three different varieties (RB72454, RB835486, and RB867515) of the cane stalk (lower, medium, and upper sections) in three harvesting periods (from May to December 2007) in an area under organic management. The juice from the upper section (from the eleventh internode to the top) of the sugar cane stalk could be indicated for the preparation of the natural ferment since it is as a source of yeasts and reducing sugars, especially the variety RB867515. Due to the seasonality, the best period for using this part of the sugar cane stalk is at the beginning of harvesting when the phenolic compounds are at low concentration, but there are higher number of Saccharomyces population and other yeast species. The high acidity in this section of the plant could result in a better control of bacterial contamination. These findings explain the traditional instructions of adding the upper sections for the preparation of natural ferment and can help its management in order to get a better performance with respect to organic cachaça production.
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The objective of the present work was to evaluate the nutritional composition of mushrooms produced in alternative substrates in agricultural and agro-industrial residues from the Amazon. C, N, pH, moisture, soluble solids, protein, lipids, total fibers, ashes, carbohydrates and energy were determined. Substrates were formulated from Simarouba amara Aubl. and Ochroma piramidale Cav. ex. Lam. Sawdust and from Bactris gasipaes Kunth and Saccharum officinarum stipe. Results showed that the nutritional composition of P. ostreatus varied according to the cultivation substrate and that it can be considered important food due to its nutritional characteristics such as: high protein content; metabolizable carbohydrates and fiber; and low lipids and calories contents.
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The present study was focused on the analysis of agronomical, nutritional, physicochemical, and antioxidant properties of six genetically different quinoa (Chenopodium quinoa Willd) genotypes cultivated in three distinctive geographical zones of Chile. Ancovinto and Cancosa genotypes from the northern Altiplano (19 ºS), Cáhuil and Faro from the central region (34 ºS), and Regalona and Villarica from the southern region (39 ºS) are representative of high genetic differentiation among the pooled samples, in particular between Altiplano and the central-southern groups. A Common-Garden Assay at 30 ºS showed significant differences among seed origins in all morphometric parameters and also in yields. Altiplano genotypes had larger panicule length but no seed production. A significant influence of the different quinoa genotypes on chemical composition and functional properties was also observed. Protein concentration ranged from 11.13 to 16.18 g.100 g-1 d.m., while total dietary fiber content ranged from 8.07-12.08 g.100 g-1 d.m., and both were the highest in Villarrica ecotype. An adequate balance of essential amino acids was also observed. Sucrose was the predominant sugar in all genotypes. Antioxidant activity was high in all genotypes, and it was highest in Faro genotype (79.58% inhibition).
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The Rhodotorularubra biomass and carotenoids production was evaluated in sugarcane juice, molasses, and syrup based media. The effects of media supplementation with urea- nitrogen or the commercial nutrient called Nitrofos KL was also verified. The experimental design used was a completely randomized factorial with 3 substrates (juice, molasses, and syrup) and three supplementations (control, urea, and Nitrofos KL). The results were submitted to variance analysis and Tukey test at 5% probability. The highest production of yeast dry mass was obtained with molasses media supplemented with urea or Nitrofos KL (15.09 and 14.87 g/L respectively). The intracellular carotenoid production was high in the media without supplementation (0.329 mg/g). The best growth medium for the volumetric production was molasses (2.74 mg/L), while those supplemented with urea and Nitrofos KL produced 2.55 and 2.32 mg/L, respectively. The major carotenoids produced were torulene, torularhodin, and β-carotene. The lowest carbohydrate consumption was observed in the sugarcane juice medium without supplementation, while the highest consumption was observed in the urea based supplementation medium.
Resumo:
The aim of this study was to evaluate of Pleurotus sajor-caju production in peach palm leaves and the addition of different fractions of mushroom powder to wheat flour to increase its nutritional value without changing its characteristics. The best yield (48.4%), biologic efficiency (4.5%), and Pr (0.36 g/day) values were obtained using 20% inoculum fraction and 10% rice bran fraction. The Pleurotus sajor-caju fruiting body cultivated under these conditions had the following composition in 100 g: 29.91 g (carbohydrates), 42.92 g (proteins), 1.24 g (lipids), 15.93 g (fibers), 7.42 g (ashes), 1.6 g (phosphorus), 2.7 g (potassium), 8.73 mg (iron), 23.75 mg (sodium), 0.34 mg (thiamine), and 0.57 mg (riboflavin). The wheat flour with mushroom powder had reduced sugar content, but it did not have increased fat content. The fiber, protein, phosphorus, potassium, iron, and riboflavin contents were increased mainly when 10% mushroom powder was added to the wheat flour. Furthermore, this flour does not undergo drastic alterations in its physicochemical characteristics such as in moisture, wet gluten, color, and falling number.