Persistent Contamination of Octopuses and Mussels with Lipophilic Shellfish Toxins during Spring Dinophysis Blooms in a Subtropical Estuary

This study investigates the occurrence of diarrhetic shellfish toxins (DSTs) and their producing phytoplankton species in southern Brazil, as well as the potential for toxin accumulation in co-occurring mussels (Perna perna) and octopuses (Octopus vulgaris). During the spring in 2012 and 2013, cells of Dinophysis acuminata complex were always present, sometimes at relatively high abundances (max. 1143 cells L⁻¹), likely the main source of okadaic acid (OA) in the plankton (max. 34 ng L⁻¹). Dinophysis caudata occurred at lower cell densities in 2013 when the lipophilic toxins pectenotoxin-2 (PTX-2) and PTX-2 seco acid were detected in plankton and mussel samples. Here, we report for the first time the accumulation of DSTs in octopuses, probably linked to the consumption of contaminated bivalves. Perna perna mussels were consistently contaminated with different DSTs (max. 42 µg kg⁻¹), and all octopuses analyzed (n = 5) accumulated OA in different organs/tissues: digestive glands (DGs) > arms > gills > kidneys > stomach + intestine. Additionally, similar concentrations of 7-O-palmytoyl OA and 7-O-palmytoly dinophysistoxin-1 (DTX-1) were frequently detected in the hepatopancreas of P. perna and DGs of O. vulgaris. Therefore, octopuses can be considered a potential vector of DSTs to both humans and top predators such as marine mammals.     

Methods for Cercospora coffeicola protoplast isolation and genetic transformation with the green fluorescent protein

Cercospora coffeicola is the causal agent of brown eye spot on coffee leaves. Although the disease has significant importance, few molecular studies have been done with C. coffeicola. Here we report a protocol for isolating protoplasts as well as development of a genetic transformation system using Green Fluorescent Protein. High yields of protoplasts (≈10⁸/ml) were obtained from mycelial cultures from five isolates of C. coffeicola. One isolate was transformed with a vector encoding hygromycin resistance and Green Fluorescent Protein. Out of 43 hygromycin-resistant transformants obtained, Green Fluorescent Protein was highly expressed in one (2.3 %).     

Isolation and selection of Hemileia Vastatrix antagonists

Organic coffee growing is rapidly increasing in Brazil, and many diseases, especially coffee leaf rust (Hemileia vastatrix), are threatening its production. This study is a first step towards a biocontrol program for coffee rust on organically grown plants. In three organic coffee farms in the state of Minas Gerais, 393 microbial strains including 154 bacterial and 239 fungal strains were isolated from leaves, leaf debris, and soil samples, and in 6 month-old coffee plants, 17 of these isolates reduced both the infection frequency (IF) and the number of H. vastatrix urediniospores produced per leaf (UPL) by more than 70 %. The isolates were identified as eight bacteria isolates, seven Bacillus spp. and one Pseudomonas sp., and nine fungal isolates, four Fusarium spp., two Penicillium spp., one Aspergillus sp., one Acremonium sp. and one Cladosporium sp. Each fungal and bacterial isolate was applied 0, 4, 8, 12 or 16 days before and 0, 4, 8, 12 or 16 days after H. vastatrix inoculation, and the efficiency in reducing both IF and UPL was evaluated. The efficiency was higher and lasted longer when the bacterial isolates were applied before H. vastatrix inoculation. Six Bacillus (B10, B25, B143, B157, B171, B175), two Fusarium (F205, F281), and one Pseudomonas (B286) isolates are potentially efficient as biocontrol agents of H. vastatrix and will be tested using field experiments.     

Net requirements of calcium, magnesium, sodium, phosphorus, and potassium for growth of Nellore × Red Angus bulls, steers, and heifers

A comparative slaughter trial was conducted to assess the net requirements for gain of Ca, P, Na, K and Mg of bulls, steers and heifers of Nellore and Red Angus crossbreds. Twenty seven F1 Nellore and Red Angus crossbred calves (9 steers, 9 bulls, and 9 heifers), averaging 274 kg BW, were used. At the beginning of the trial, three animals from each gender were slaughtered to determine the initial body composition. The remaining 18 animals (3 animals of each gender) were randomly assigned to two treatments: fed 0.75 or 1.5% of BW of concentrate. The diets were based on corn silage and were isonitrogenous (2% N, DM). After three growing periods of 28 d, all animals were slaughtered. The cleaned gastrointestinal tract, organs, carcass, head, hide, tail, feet, and tissues were weighed to determine the empty BW (EBW). These parts were ground separately and subsampled for chemical analyses. The log of the contents of each mineral in the empty body was regressed on the log of the EBW to estimate the net requirement for each mineral per kg of empty body gain (EBG). There were no differences (P > 0.05) in the net requirements for growth of all macrominerals among genders. The equations of the pooled data of the net requirements for growth (g/kg EBG) were: 332.6 × EBW ^− 0.6367 for Ca, 112.1 × EBW ^− 0.5615 for P, 10.85 × EBW ^− 0.3992 for Na, 4.01 × EBW ^− 0.153 for K, and 3.589 × EBW ^− 0.462 for Mg. Our findings indicated that retained Ca and retained P were poorly related to the retained protein.     

Medium Light and Medium Roast Paper-Filtered Coffee Increased Antioxidant Capacity in Healthy Volunteers: Results of a Randomized Trial

We compared the effects of medium light roast (MLR) and medium roast (MR) paper-filtered coffee on antioxidant capacity and lipid peroxidation in healthy volunteers. In a randomized crossover study, 20 volunteers consumed 482?±?61?ml/day of MLR or MR for four weeks. Plasma total antioxidant status (TAS), oxygen radical absorbance capacity (ORAC), oxidized LDL and 8-epi-prostaglandin F2α, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activity were measured at baseline and after the interventions. MLR had higher chlorogenic acids-(CGA; 334?mg/150?mL) and less caffeine (231?mg/150?ml) than MR had (210 and 244?mg/150?ml, respectively). MLR also had fewer Maillard reaction products (MRP) than MR had. Compared with baseline, subjects had an increase of 21 and 26?% in TAS, 13 and 13?% in CAT, 52 and 75?% in SOD, and 62 and 49?% in GPx after MLR and MR consumption (P?相似文献   

Glyphosate sustainability in South American cropping systems

South America represents about 12% of the global land area, and Brazil roughly corresponds to 47% of that. The major sustainable agricultural system in South America is based on a no-tillage cropping system, which is a worldwide adopted agricultural conservation system. Societal benefits of conservation systems in agriculture include greater use of conservation tillage, which reduces soil erosion and associated loading of pesticides, nutrients and sediments into the environment. However, overreliance on glyphosate and simpler cropping systems has resulted in the selection of tolerant weed species through weed shifts (WSs) and evolution of herbicide-resistant weed (HRW) biotypes to glyphosate. It is a challenge in South America to design herbicide- and non-herbicide-based strategies that effectively delay and/or manage evolution of HRWs and WSs to weeds tolerant to glyphosate in cropping systems based on recurrent glyphosate application, such as those used with glyphosate-resistant soybeans. The objectives of this paper are (i) to provide an overview of some factors that influence WSs and HRWs to glyphosate in South America, especially in Brazil, Argentina and Paraguay soybean cropped areas; (ii) to discuss the viability of using crop rotation and/or cover crops that might be integrated with forage crops in an economically and environmentally sustainable system; and (iii) to summarize the results of a survey of the perceptions of Brazilian farmers to problems with WSs and HRWs to glyphosate, and the level of adoption of good agricultural practices in order to prevent or manage it.     

Photocatalytic Efficiency of TiO<Subscript>2</Subscript> Supported on Raw Red Clay Disks to Discolour Reactive Red 141

In this work, disks containing different amount of the TiO₂ precursor impregnated on the raw red clay were produced. The disks were obtained by pressing in metal template and subsequently calcined at 500 °C. The raw clay was used as rigid support to fix the TiO₂. The materials were characterized by X-ray diffraction, diffuse reflectance spectroscopy, N₂ adsorption-desorption (BET and BJH), scanning electron microscopy, and Fourier transform infrared (FTIR) spectroscopy. The ability of disks to produce superoxide and hydroxyl radicals after photoexcitation with UV irradiation was monitored by EPR. The catalytic efficiency was evaluated by the Reactive Red 141 dye discoloration under artificial UV light and sunlight. The reaction parameters such as concentration of RR-141 and irradiation source were evaluated. The results showed that the disks were able to decolorize 97.5% under sunlight at 60 min. The disks were also efficient in the discoloration until the tenth cycle, resulting in discoloration values near the initial cycles. Additionally, the dye fragments produced in cleavage of molecule during the reaction were evaluated by LC/MS-MS.

Open image in new window

Graphical Abstract