Enhancing microalgae biomass production: Exploring improved scraping frequency in a hybrid cultivation system.

Recently, hybrid systems, such as those incorporating high-rate algal ponds (HRAPs) and biofilm reactors (BRs), have shown promise in treating domestic wastewater while cultivating microalgae. In this context, the objective of the present study was to determine an improved scraping frequency to maximize microalgae biomass productivity in a mix of industrial (fruit-based juice production) and domestic wastewater. The mix was set to balance the carbon/nitrogen ratio. The scraping strategy involved maintaining 1 cm wide stripes to retain an inoculum in the reactor. Three scraping frequencies (2, 4, and 6 days) were evaluated. The findings indicate that a scraping frequency of each 2 days provided the highest biomass productivity (18.75 g total volatile solids m-2 d-1). The species' behavior varied with frequency: Chlorella vulgaris was abundant at 6-day intervals, whereas Tetradesmus obliquus favored shorter intervals. Biomass from more frequent scraping demonstrated a higher lipid content (15.45%). Extrapolymeric substance production was also highest at the 2-day frequency. Concerning wastewater treatment, the system removed 93% of dissolved organic carbon and ∼100% of ammoniacal nitrogen. Combining industrial and domestic wastewater sources to balance the carbon/nitrogen ratio enhanced treatment efficiency and biomass yield. This study highlights the potential of adjusting scraping frequencies in hybrid systems for improved wastewater treatment and microalgae production.

Effect of brewery effluent inhibitors on Rhodotorula toruloides NCYC 921 cells grown in pure and mixed cultures at pH 4 and 6.

The presence of inhibitor compounds in the culture medium can cause severe effects on the microorganisms cells. Brewery wastewaters present organic acids (acetic, propionic and butyric acids) which can severely affect yeast cells metabolism, when grown in pure cultures, although in mixed cultures they are able to develop. To understand the physiological changes on Rhodotorula toruloides (formerly Rhodosporidium toruloides) cells when fermenting in the presence of the organic acids present in brewery wastewater, pure and mixed cultures with the microalga Tetradesmus obliquus were performed in a synthetic medium containing the same organic acids concentrations that are present in brewery wastewater at pH 4 and 6. It was concluded that, at pH 4, the organic acids effects in the yeast cells were much more toxic than at pH 6. Moreover, mixed cultures can be an advantage over heterotrophic pure cultures as the microalga is able to contribute for the consumption of potential inhibitors for the yeast.

Rhodosporidium toruloides and Tetradesmus obliquus Populations Dynamics in Symbiotic Cultures, Developed in Brewery Wastewater, for Lipid Production.

In this work, primary brewery wastewater (PBWW) and secondary brewery wastewater (SBWW) separately, or mixed at the ratios of 1:1 (PBWW:SBWW) and 1:7 (PBWW:SBWW), with or without supplementation with sugarcane molasses (SCM), were used as culture media for lipid production by a mixed culture of the oleaginous yeast Rhodosporidium toruloides NCYC 921 and the microalgae Tetradesmus obliquus (ACOI 204/07). Flow cytometry was used to understand the dynamics of the two micro-organisms during the mixed cultures evolution, as well as to evaluate the physiological states of each micro-organism, in order to assess the impact of the different brewery effluent media composition on the microbial consortium performance. Both brewery wastewaters (primary and secondary) without supplementation did not allow R. toruloides heterotrophic growth. Nevertheless, all brewery wastewater media, with and without SCM supplementation, allowed the microalgae growth, although the yeast was the dominant population. The maximum total biomass concentration of 2.17 g L-1 was achieved in the PBWW mixed cultivation with 10 g L-1 of SCM. The maximum lipid content (14.86% (w/w DCW)) was obtained for the mixed culture developed on SBWW supplemented with 10 g L-1 of SCM. This work demonstrated the potential of using brewery wastewater supplemented with SCM as a low-cost culture medium to grow R. toruloides and T. obliquus in a mixed culture for brewery wastewater treatment with concomitant lipid production.

Cemetery, tombstones, tears and hidden silences: Suicide in children and adolescents.

Recent studies have reported a deterioration in children's mental health since the onset of the COVID-19 pandemic, with an increase in anxiety and mood disorders leading to significant suicidal ideation and suicide rates. Suicide is complex, and individual tragedies and circumstances can diverge. Evidence suggests that the mental health and well-being of some children and youth were substantially affected because of and during the pandemic. Those with pre-existing mental health problems that experienced the most negative impacts compared to pre-pandemic data.

Victims of sexual exploitation and violence in Brazil.

At least 8.9% of Brazilian women have already suffered some type of sexual violence in their lives. Every hour, Brazil has 2.2 cases of sexual violence against children and adolescents. Of the approximately 35,000 cases of violence against children and adolescents in 2021, in around 12,000 ethnic groups were not identified, 10,064 were white, 9634 were brown, 2505 black, 141 yellow, and 61 indigenous. If compared to age groups, boys from zero to 6 years reach 30%, but when the age is 12 to 18, women reach 91% of the victims. The whistleblowers are almost always anonymous, unlike in the case of violence against women, which are usually the victims themselves who complain or when they are third parties, they are usually identified. According to official data, around 96% of sexual violence takes place at home. The data are frightening and prove that sexual violence is the result of a scenario of gender inequality because it affects the lives of girls and women in a much more profound way.

Deaths announced in Brazil - A dark sweetness: COVID-19 among children and adolescents.

While the Ministry of Health of Brazil postpones the inclusion of children aged 5-12 years in the National Immunization Plan against COVID-19, current evidence highlights that the number of hospitalizations and deaths caused by COVID-19 in the pediatric population, of in general, including the group of children aged 5-11 years, it is not within acceptable levels. Unfortunately, child mortality and fatality rates in Brazil are among the highest in the world. In 2020, there were 1203 deaths from Severe Acute Respiratory Syndrome (SRAG). In 2021, there were 2293. Also 65 deaths were reported from Pediatric Multisystem Inflammatory Syndrome (P-SIM); an aggressive manifestation of the virus in children.

"When night falls": Violence against women and its repercussions on children and adolescents.

Violence against women is a profound global injustice. It is a major obstacle to fulfilling the human rights of women and their children. Confined to their aggressors, women exposed to this violence have even greater difficulty in accessing support networks and care services. Furthermore, the economic impact of the pandemic, which disproportionately affected women, created additional barriers. In reality, however, femicide is forgotten, underestimated, and poorly prosecuted throughout the world. In this context, more than 100 children witnessed a murder or were at home when it took place. This form of indirect violence is vicarious, in which children are left out, anonymous, and invisible. The trauma generated potentiates mentalization difficulties, emotional dependence, and instability in future relationships, caused by pain and psychological suffering.

Pandemic of hunger: The severe nutritional deficiency that kills Yanomami ethnic children.

Chronic malnutrition is the painful reality that Yanomami children face in Brazil's largest Indigenous Land and is pointed out by specialists as one of the results of the federal government's "anti-indigenous policy". The lack, or scarcity, of medical care, together with the lack of environmental inspection, pushes the Yanomami into a desperate scenario. It is estimated that 20,000 illegal miners operate in the territory. Mining activity contaminates rivers with mercury and has caused deformities and illnesses in women and children. They live on the largest indigenous reserve in Brazil. There are nine million hectares within the Amazon Forest. Malaria has persistently advanced in Yanomami land: there are more than 16,000 cases this year alone. Several children are dying.

Echoes of Global Silence: Is there protection and safety for Venezuelan children and adolescents?

As the crisis in Venezuela deepens, an increasing number of children urgently needs shelter, protection, and access to basic services, including food, medicine, clean water, and sanitation. Children and young people in transit are particularly at risk of criminal activity or being separated from their families. The consequences of the humanitarian crisis for children could be devastating for the country's future. The child labor problem was fueled by a mass migration of more than five million Venezuelans that turned many children into livelihoods for their families. The pandemic has aggravated risk factors for child labor. The work ranges from working in dumps to agricultural fields, adding that children in rural areas are more likely to depend on public assistance and are at greater risk of being recruited by gangs. Some Venezuelan women and girls are traveling for hours or days to cross the Colombian border and earn money as sex workers. The complex and multifaceted reality of international migration reveals enormous challenges that directly affect the lives of children and adolescents, especially the most vulnerable, and demand urgent responses from the constituted powers and civil society in the face of countless human rights violations those people experience.

Impact of High-Pressure Homogenization on the Cell Integrity of Tetradesmus obliquus and Seed Germination.

Microalgae have almost unlimited applications due to their versatility and robustness to grow in different environmental conditions, their biodiversity and variety of valuable bioactive compounds. Wastewater can be used as a low-cost and readily available medium for microalgae, while the latter removes the pollutants to produce clean water. Nevertheless, since the most valuable metabolites are mainly located inside the microalga cell, their release implies rupturing the cell wall. In this study, Tetradesmus obliquus grown in 5% piggery effluent was disrupted using high-pressure homogenization (HPH). Effects of HPH pressure (100, 300, and 600 bar) and cycles (1, 2 and 3) were tested on the membrane integrity and evaluated using flow cytometry and microscopy. In addition, wheat seed germination trials were carried out using the biomass at different conditions. Increased HPH pressure or number of cycles led to more cell disruption (75% at 600 bar and 3 cycles). However, the highest increase in wheat germination and growth (40-45%) was observed at the lowest pressure (100 bar), where only 46% of the microalga cells were permeabilised, but not disrupted. Non-treated T. obliquus cultures also revealed an enhancing effect on root and shoot length (up to 40%). The filtrate of the initial culture also promoted shoot development compared to water (21%), reinforcing the full use of all the process fractions. Thus, piggery wastewater can be used to produce microalgae biomass, and mild HPH conditions can promote cell permeabilization to release sufficient amounts of bioactive compounds with the ability to enhance plant germination and growth, converting an economic and environmental concern into environmentally sustainable applications.

Combining biotechnology with circular bioeconomy: From poultry, swine, cattle, brewery, dairy and urban wastewaters to biohydrogen.

The ability of microalgae to grow in nutrient-rich environments and to accumulate nutrients from wastewaters (WW) makes them attractive for the sustainable and low-cost treatment of WW. The valuable biomass produced can be further used for the generation of bioenergy, animal feed, fertilizers, and biopolymers, among others. In this study, Scenedesmus obliquus was able to remove nutrients from different wastewaters (poultry, swine and cattle breeding, brewery and dairy industries, and urban) with removal ranges of 95-100% for nitrogen, 63-99% for phosphorus and 48-70% for chemical oxygen demand. The biomass productivity using wastewaters was higher (except for poultry) than in synthetic medium (Bristol), the highest value being obtained in brewery wastewater (1025 mg/(L.day) of freeze-dried biomass). The produced biomass contained 31-53% of proteins, 12-36% of sugars and 8-23% of lipids, regardless of the type of wastewater. The potential of the produced Scenedesmus obliquus biomass for the generation of BioH2 through batch dark fermentation processes with Enterobacter aerogenes was evaluated. The obtained yields ranged, in mL H2/g Volatile Solids (VS), from 50.1 for biomass from anaerobically digested cattle WW to 390 for swine WW, whereas the yield with biomass cultivated in Bristol medium was 57.6 mL H2/gVS.

Energetic valorization of algal biomass in a hybrid anaerobic reactor.

This study evaluated the operation of a hybrid anaerobic reactor fed with algal biomass cultivated in effluent from the brewery industry. Three stages of operation were distinguished during the 72 days of semi-continuous functioning of the reactor: Stage 1 (S1), in which algal biomass was used as substrate; Stage 2 (S2), in which 10% (v/v) of the algal biomass was substituted by olive mill wastewater (OMW); and Stage 3 (S3), in which algal biomass was heat pre-treated. During S1, a loss of solids was observed, with an increment of organic matter in the outlet. The substitution of 10% of the volume of algal biomass by OMW tripled the methane productivity obtained in the previous stage by digestion of pure algal biomass. Heat pre-treatment was not efficient in rupturing the cell wall, and consequently did not have any effect on the increase in biogas production. The complementarity of substrates in the assessed conditions led to better results than the pre-treatment of the algal biomass.

Bioenergy recovery from cattle wastewater in an UASB-AF hybrid reactor.

New data on biogas production and treatment of cattle wastewater were registered using an upflow anaerobic sludge blanket-anaerobic filter (UASB-AF) hybrid reactor under mesophilic temperature conditions (37 °C). The reactor was operated in semi-continuous mode with hydraulic retention times of 6, 5, 3 and 2 days and organic loading rates of 3.8, 4.6, 7.0 and 10.8 kg CODt m-3 d-1. Biogas volumes of 0.6-0.8 m3 m-3 d-1 (3.8-4.6 kg CODt m-3 d-1) and 1.2-1.4 m3 m-3 d-1 (7.0-10.8 kg CODt m-3 d-1), with methane concentrations between 69 and 75%, were attained. The removal of organic matter with values of 60-81% (CODt) and 51-75% (CODs) allowed methane yields of 0.155-0.183 m3 CH4 kg-1 CODt and 0.401-0.513 m3 CH4 kg-1 CODs to be obtained. Volatile solids were removed in 34 to 69%, with corresponding methane yields of 0.27 to 0.42 m3 CH4 kg-1 VSremoved. The good performance of the novel hybrid reactor was demonstrated by biogas outputs higher than reported previously in the literature, along with the quality of the gas obtained in the various experimental phases. The hybrid reactor investigated in this study presents comparative advantages, particularly in relation to conventional complete mixture units, considering economic factors such as energy consumption, reactor volume and installation area.

Biodiesel from wastewater: lipid production in high rate algal pond receiving disinfected effluent.

The production of different species of microalgae in consortium with other micro-organisms from wastewaters may represent an alternative process, to reduce the costs, for obtaining biofuels. The aim of this study was to evaluate the influence of pre-ultraviolet disinfection (UV) in the production of lipids from biomass produced in high rate ponds. Two high rate algal ponds were evaluated: a pond that received domestic sewage without disinfection and the other receiving domestic sewage previously disinfected by UV radiation (uvHRAP). The UV disinfection did not lead to significant differences in fatty acid profile and total lipid productivities, although it increased algal biomass concentration and productivity as well as lipid content. Moreover, the overall biomass concentrations and productivities decreased with the UV disinfection, mostly as a consequence of a loss in bacterial load. We thus conclude that uvHRAP disinfection may represent a potential strategy to promote the cleaner and safer growth of algal biomass when cultivated in consortium with other micro-organisms. Mainly regarding the use of wastewater as culture medium, together with a cheaper production of lipids for biodiesel, pre-disinfection may represent an advance since extraction costs could be significantly trimmed due to the increase in lipid content.

Microalgal symbiosis in biotechnology.

This review provides an analysis of recent published work on interactions between microorganisms, especially the ones involving mainly nutrient exchanges and at least with one microalga species. Examples of microbial partners are given, with a remark to the potential application of cultures of an autotroph and a heterotroph, which grow simultaneously, taking advantage of the complementary metabolisms. These are particularly interesting, either due to economic or sustainable aspects, and some applications have already reached the commercial stage of development. The added advantages of these symbiotic cultures are biomass, lipid, and other products productivity enhancement a better utilization of resources and the reduction or even elimination of process residues (including carbon dioxide and other greenhouse gases) to conduct an increasingly greener biotechnology. Among the several symbiotic partners referred, the microalgae and yeast cultures are the most used. The interaction between these two microorganisms shows how to enhance the lipid production for biodiesel purposes compared with separated (stand-alone) cultures.

Integrated microbial processes for biofuels and high value-added products: the way to improve the cost effectiveness of biofuel production.

The production of microbial biofuels is currently under investigation, as they are alternative sources to fossil fuels, which are diminishing and their use has a negative impact on the environment. However, so far, biofuels derived from microbes are not economically competitive. One way to overcome this bottleneck is the use of microorganisms to transform substrates into biofuels and high value-added products, and simultaneously taking advantage of the various microbial biomass components to produce other products of interest, as an integrated process. In this way, it is possible to maximize the economic value of the whole process, with the desired reduction of the waste streams produced. It is expected that this integrated system makes the biofuel production economically sustainable and competitive in the near future. This review describes the investigation on integrated microbial processes (based on bacteria, yeast, and microalgal cultivations) that have been experimentally developed, highlighting the importance of this approach as a way to optimize microbial biofuel production process.

Identity of care in a Psychosocial Care Center for Children and Adolescents who uses drugs.

Objective To associate the territory of identity with the production of care within a PCC focusing on children and adolescents with drug abuse and their institutional identity. Method We used the " process tracing methodology" in four research categories: focus groups, characterization of professionals, observing the everyday and interviewing two members of emblematic cases of the service. Results territory of identity of the institution, which operates the production of care is crossed by the difficulty of dealing with the complexity brought by the users and the performance of the PCC network. This paper is also permeated by different conceptions of care and small problematization of these issues in collective spaces of service. Conclusion The discussion in focus groups and other devices can be powerful resources to reframe the meaning of care and identity of collective service.

Assessment of ß-carotene content, cell physiology and morphology of the yellow yeast Rhodotorula glutinis mutant 400A15 using flow cytometry.

Flow cytometry was used to assess ß-carotene content, cell membrane permeability, cell size and granularity in Rhodotorula glutinis mutant 400A15 grown under different oxygen transfer coefficients (k L a) and carbon to nitrogen ratios (C/N). A Doehlert distribution was used in order to select the best conditions that induced the highest carotenoids production. The highest ß-carotene content (0.79 mg g(-1) DCW) at the lowest k L a and C/N (5 × 10(-3) s(-1) and 11.3 respectively). Under these conditions, the biomass concentration attained 18.60 g L(-1). The highest ratio of cells with permeabilised membranes (2.6 %), and the highest cell size and granularity were also obtained under these conditions. It was observed that C/N showed a stronger influence than the k L a on the measured cell parameters.

Electroconvulsive therapy use in adolescents: a systematic review.

BACKGROUND: Considered as a moment of psychological vulnerability, adolescence is remarkably a risky period for the development of psychopathologies, when the choice of the correct therapeutic approach is crucial for achieving remission. One of the researched therapies in this case is electroconvulsive therapy (ECT). The present study reviews the recent and classical aspects regarding ECT use in adolescents. METHODS: Systematic review, performed in November 2012, conformed to the PRISMA statement. RESULTS: From the 212 retrieved articles, only 39 were included in the final sample. The reviewed studies bring indications of ECT use in adolescents, evaluate the efficiency of this therapy regarding remission, and explore the potential risks and complications of the procedure. CONCLUSIONS: ECT use in adolescents is considered a highly efficient option for treating several psychiatric disorders, achieving high remission rates, and presenting few and relatively benign adverse effects. Risks can be mitigated by the correct use of the technique and are considered minimal when compared to the efficiency of ECT in treating psychopathologies.

Algal biomass production and wastewater treatment in high rate algal ponds receiving disinfected effluent.

Algal biomass production associated with wastewater is usually carried out in high rate algal ponds (HRAPs), which are concomitantly used in the treatment of such effluent. However, most types of wastewater have high levels of bacteria that can inhibit the growth of algal biomass by competing for space and nutrients. The objective of this study was to assess the influence of ultraviolet (UV) pre-disinfection on the performance of HRAPs used for wastewater treatment and algal biomass production. Two HRAPs were tested: one received effluent from an upflow anaerobic sludge blanket (UASB) reactor- HRAP -and the second received UASB effluent pre-disinfected by UV radiation-(UV)HRAP. Physical, chemical and microbiological parameters were monitored, as well as algal biomass productivity and daily pH and dissolved oxygen (DO) variation. The (UV)HRAP presented highest DO and pH values, as well as greater percentage of chlorophyll a in the biomass, which indicates greater algal biomass productivity. The average percentages of chlorophyll a found in the biomass obtained from the HRAP and the (UV)HRAP were 0.95 +/- 0.65% and 1.58 +/- 0.65%, respectively. However, total biomass productivity was greater in the HRAP (11.4 gVSSm(-2) day(-1)) compared with the (UV)HRAP (9.3 gVSSm(-2) day(-1)). Mean pH values were 7.7 +/- 0.7 in the HRAP and 8.1 +/- 1.0 in the (UV)HRAP, and mean values of DO percent saturation were 87 +/- 26% and 112 +/- 31% for the HRAP and the (UV)HRAP, respectively. Despite these differences, removal efficiencies of organic carbon, chemical oxygen demand, ammoniacal nitrogen and soluble phosphorus were statistically equal at the 5% significance level.