Removal of Chromium, Copper, and Nickel from an Electroplating Effluent Using a Flocculent Brewer’s Yeast Strain of Saccharomyces cerevisiae

The release of heavy metals in aquatic systems due to the discharge of industrial wastewaters is a matter of environmental concern. Heat-inactivated cells of a flocculent strain of Saccharomyces cerevisiae were used in the bioremediation, in a batch mode, of a real electroplating effluent containing Cu, Ni, and Cr. In this approach, no previous reduction of Cr(VI) to Cr(III) was required. Cr(VI) was selectively removed (98%) by yeast biomass at pH 2.3. At this pH, Cr(VI) is mainly in the form of HCrO ₄ ^? and yeast surface is surrounded by H⁺ ions, which enhance the Cr(VI) interaction with biomass binding sites by electrostatic forces. Subsequently, pH of the effluent was raised up to 6.0; this pH maximizes the efficiency of cations removal since at this pH the main binding groups of yeast cells are totally or partially deprotonated. The passage of effluent through a series of sequential batches, at pH 6.0, allowed, after the third batch, the removal of Cu(II), Ni (II), Cr total, and Cr(VI) in the effluent to values below the legal limit of discharge. The strategy proposed in the present work can be used in plants for the treatment of heavy metals rich industrial effluents containing simultaneously Cr(VI) and Cr(III).     

Effect of adenosine infusion on isoflurane MAC in dogs.

Adenosine is a potent analgesic in people and reduces the MAC of halothane in dogs. The purpose of this study was to determine whether adenosine reduces the MAC of isoflurane in dogs. Seven beagles (four males and three females) were anesthetized and randomly assigned to receive adenosine (0.3 mg kg^–1 minute^–1; 6 mL kg^–1 hour^–1, IV) or saline (0.9%, 6 mL kg^–1 hour^–1IV). After an interval of ≥7 days, each dog was reanesthetized and treated with the alternate infusion. Anesthesia was induced and maintained with isoflurane in oxygen. Dogs were intubated and instrumented for measurement of mean systemic arterial blood pressure and airway concentration of isoflurane and end‐tidal partial pressure of carbon dioxide. The MAC for isoflurane was determined using the tail‐clamp technique. Baseline MAC values were 1.25 (1.15, 1.35)% [median (minimum, maximum)] and 1.25 (1.05, 1.45)% before the saline and adenosine treatments, respectively. After 2 hours of infusion with saline or adenosine, MAC values were not different (p = 0.156) and were 1.25 (0.95, 1.35)% and 1.05 (1.00, 1.25)%, respectively. Two hours following the end of each infusion, the MAC values for saline and adenosine treatment groups differed significantly (p = 0.015), but by no more than the normal variation inherent in this study, and were 1.15 (1.15, 1.35)% and 1.05 (1.05, 1.25)%, respectively. Mean arterial blood pressure was 93 (74, 123) mm Hg for saline treated dogs and 67 (52, 72) mm Hg (p = 0.008) during adenosine infusion. End‐tidal carbon dioxide was not different between the two treatment groups. We conclude that adenosine administered at 0.3 mg kg^–1 minute^–1had no effect on isoflurane MAC in dogs, but decreased mean arterial blood pressure.     

Morphological and molecular characterization of Colletotrichum spp. from citrus orchards affected by postbloom fruit drop in Brazil

Brazilian isolates of Colletotrichum spp. from citrus orchards affected by postbloom fruit drop were examined for colony colour, mycelial growth, benomyl-resistance, pathogenicity, and genetic variability by random amplified polymorphic DNA (RAPD) analysis. All isolates were obtained from flowers and persistent calyxes from different citrus hosts from Sao Paulo, Brazil. DNA polymorphisms detected after amplification with random 10-mer primers were used to classify the isolates into two groups. Group I isolates grew rapidly on potato-dextrose agar (PDA) and were sensitive to benomyl, and group II isolates grew slowly on PDA and were benomyl-resistant. Colletotrichum acutatum was analyzed by RAPD and had high genetic similarity with group II isolates of Colletotrichum from citrus. Probably, the group I is C. gloeosporioides and group II is C. acutatum.     

Brazilian biosafety law and the new breeding technologies

Globally, the area of land cultivated with genetically modified (GM) crops has increased a thousand-fold over the last two decades. Although this technology has become important for food production, the regulatory frameworks that underpin these outcomes are based on a list of requirements for a risk assessment that differ from country to country. In recent years, policymakers have had the opportunity to learn from the controversies over transgenics to create effective regulatory milestones for emerging technologies, allowing them to reach their potential for a more sustainable agriculture, ensuring food security. In Brazil, Law No. 11.105 of 24 March 2005 established a framework with four main organizations responsible for risk assessment and management. However, most of new breeding technologies did not exist at that time and were not considered in this law. In 2016, Normative Resolution No. 16 of the National Biosafety Technical Commission (CTNBio) was established to address this gap based on the evaluation of the products obtained through these techniques (termed Innovative Precision Improvement Techniques in the resolution), in a case-by-case consultation system. Briefly, if the product is designated to be a GM, the developer will have to go through the biosafety requirements and will be approved only after CTNBio risk assessment. If the product is designated not to be GM (for the purposes of the legislation), then it can be registered using the existing procedures. Currently, 152 GM products are commercially approved in Brazil. In 2018, CTNBio assessed the first consultation on commercial release of plants generated using the new breeding technologies and has subsequently approved six products. It is expected that many institutions would be able to participate in Brazilian and world markets, developing and introducing new biotechnological solutions and products through a more sustainable approach and without facing public disapproval, a common issue for GM crops.     

Aurantiochytrium sp. meal can replace fish oil in practical diets for the juvenile Pacific white shrimp

This study evaluated the use of microalgae (Aurantiochytrium sp.) meal as a substitute for fish oil in the diet of juvenile Pacific white shrimp (Litopenaeus vannamei) reared in a clear‐water system. Dietary treatments at five replacement levels (0%, 25%, 50%, 75%, 100%) were performed in triplicate. After 46 days, only a slight difference in shrimp final weight was observed among treatments (0.61 g). An increase in final weight was observed with replacement of up to 50% fish oil for microalgae meal, while the optimal percentage of replacement estimated was 44.7%. Feed conversion rate (FCR) of animals fed a diet of Aurantiochytrium sp.meal to replace up to 50% fish oil decreased, and the optimal percentage of replacement estimated was 49.3%. The fatty acids profile in shrimp muscle tissue demonstrated an increase in docosahexaenoic acid (DHA) from 10.03% to 14.28% with increased replacement of fish oil by microalgae meal in the diet. Therefore, the partial replacement of fish oil by microalgae meal resulted in improved shrimp growth and FCR, and total replacement of dietary fish oil had no negative effects on these parameters. In addition, inclusion of microalgae meal raises the level of DHA in shrimp muscle.     

Essential oils in diets for Nile tilapia juveniles: Productive performance and plasmatic biochemistry

The objective of this study was to evaluate the inclusion of increasing levels of a commercial mix of essential oils (EOs) from cashew (Anacardium occidentale) and castor bean (Ricinus communis) as an additive in diets for Nile tilapia. Thus, 240 juveniles with an initial weight of 35.06 ± 1.02 g were distributed in a completely randomized design (four treatments and six replicates) in 24 cylindrical‐tapered tanks; the fish were fed for 60 days, four times a day, diets containing increasing levels of EO (0.10, 0.15 and 0.20%) and a control diet (without the additive). After the experimental period, the animals were desensitized, and an aliquot of blood was collected for the biochemical analysis; they were subsequently euthanized for the evaluation of productive performance and fillet chemical composition. No significant differences (p > .05) were observed in the analyses of productive performance, fillet chemical composition, and triglycerides, VLDL, total proteins, urea and glucose. However, significant differences (p < .05) were observed in the analyses of total cholesterol, HDL and LDL. Inclusion above 0.15 of the additive showed an improvement in the levels of lipoprotein carriers, increasing HDL levels and decreasing LDL values, without interfering with the fish productive performance.     

Studies on Aftertaste of Tea

Aftertaste is a taste perceiption after a food or beverage is either swallowed or spat out.The primary taste processing area located in the insula was considered to be involved in aftertaste perception.The changes in chemical compositions lead to the changes in aftertaste of tea.Tea fermentation,in which tea catechins are transformed into thearubigins,lead to a strong,distinctive flavor but a plain aftertaste.Theanine has a sweet taste,with little or no aftertaste.The bitter aftertaste of transglucosylated steviosides was reduced when they were converted through transglucosylation of stevioside by α-amylase.Characteristics of aftertaste include quality,intensity,and duration.Foods that have lingering aftertastes typically have long sensation durations.A surface plasmon resonance （SPR） system immobilized β-cyclodextrin indicated larger responses for the gallate-type catechins in comparison to the non-gallate-type catechins.The β-cyclodextrin/SPR system can sense the bitter-astringent taste intensity of the green tea.The SPR system detected the stability of the complex between the gallate-type catechins and β-cyclodextrin,which can be interpreted as the aftertaste produced in humans by the gallate-type catechins.     

Different levels of organic trace minerals in diets for Nile tilapia juveniles alter gut characteristics and body composition,but not growth

Thirty groups of twenty juveniles each of Nile tilapia (Oreochromis niloticus, initial average weight 23.93 ± 0.80 g) were fed diets containing increasing amounts (0%, 25%, 50%, 75%, and 100% of levels used by the tilapia feed industry) of organic trace mineral (Fe, Zn, Mn, Cu, Se) supplementation for 56 days. Growth was not affected by the dose of mineral supplementation. However, body protein increased in fish fed intermediate doses of organic minerals, reaching a maximum at 40.44% supplementation. Doses >50% showed mild damage to the intestinal tissue. Body Fe, Zn and Cu deposition were highest at 28.32%, 24.43% and 78.45% supplementation, respectively. Tilapia could modulate intestinal morphology when fed different doses of organic minerals. As the supplementation doses increased, hemosiderin staining increased in the distal intestine and total body Fe content, indicating that the distal region of the intestine plays an important role in iron excretion by tilapia. Supplementation of organic trace minerals at intermediate doses does not harm Nile tilapia growth, but excessive trace mineral supplementation can impair body protein retention and promote histological alterations in the gut.     

Phosphorus Removal from Eutrophic Waters with an Aluminium Hybrid Nanocomposite

An excess of phosphorus (P) is the most common cause of eutrophication of freshwater bodies. Thus, it is imperative to reduce the concentration of P to prevent harmful algal blooms. Moreover, recovery of P has been gaining importance because its natural source will be exhausted in the near future. Therefore, the present work investigated the removal and recovery of phosphate from water using a newly developed hybrid nanocomposite containing aluminium nanoparticles (HPN). The HPN-Pr removes 0.80?±?0.01?mg?P/g in a pH interval between 2.0 and 6.5. The adsorption mechanism was described by a Freundlich adsorption model. The material presented good selectivity for phosphate and can be regenerated using an HCl dilute solution. The factors that contribute most to the attractiveness of HPN-Pr as a phosphate sorbent are its moderate removal capacity, feasible production at industrial scale, reuse after regeneration and recovery of phosphate.