CLI: A new protocol for the isolation of Lactic Acid Bacteria from complex plant samples.

Lactic Acid Bacteria (LAB) are predominantly probiotic microorganisms and the most are Generally Recognized As Safe (GRAS). LAB inhabit in the human gut ecosystem and are largely found in fermented foods and silage. In the last decades, LAB have also has been found in plant microbiota as a new class of microbes with probiotic activity to plants. For this reason, today the scientific interest in the study and isolation of LAB for agronomic application has increased. However, isolation protocols from complex samples such as plant tissues are scarce and inefficient. In this study, we developed a new protocol (CLI, Complex samples LAB Isolation) which yields purified LAB from plants. The sensitivity of CLI protocol was sufficient to isolate representative microorganisms of LAB genera (i.e. Leuconostoc, Lactococcus and Enterococcus). CLI protocol consists on five steps: i) sample preparation and pre-incubation in 1% sterile peptone at 30 °C for 24-48 h; ii) Sample homogenization in vortex by 10 min; iii) sample serial dilution in quarter-strength Ringer solution, iv) incubation in MRS agar plates with 0.2% of sorbic acid, with 1% of CaCO3, O2 < 15%, at pH 5.8 and 37 °C for 48 h.; v) Selection of single colonies with LAB morphology and CaCO3-solubilization halo. Our scientific contribution is that CLI protocol could be used for several complex samples and represents a useful method for further studies involving native LAB.

Uncovering the Work-Family Interface: The Impact of Facilitators and Stressors on the Health of Farm Women.

Work-family interface (WFI) theory has identified many stressors that influence work-family dynamics from the standpoint of employees. However, work-family facilitators, as well as the effects of gender differences and the impact of sociocultural environments that differ from a formal employment situation, have received much less attention. Our research aimed to fill these theoretical gaps by analyzing the facilitators and stressors involved in work-family dynamics and determining their consequences for farm women's physical, psychological, and social health. We used a qualitative method with a grounded theory design to collect data via semi-structured interviews with 46 farm women from the region of Araucanía in Chile. Our results explain how facilitators, stressors, and outcomes take place in a process of work-family balance that, paradoxically, implies exhausting journeys, a gender-based overload, a risk of diffuse body pain and distress, and a lack of time for personal healthcare and productive autonomy. Addressing these issues requires a comprehensive approach involving improved healthcare infrastructure and services focused on changing the pressures that the farming WFI exerts on rural women.

Proteomic response to phosphorus deficiency and aluminum stress of three aluminum-tolerant phosphobacteria isolated from acidic soils.

Aluminum (Al)-tolerant phosphobacteria enhance plant growth in acidic soils by improving Al complexing and phosphorus (P) availability. However, the impact of Al stress and P deficiency on bacterial biochemistry and physiology remains unclear. We investigated the single and mutual effects of Al stress (10 mM) and P deficiency (0.05 mM) on the proteome of three aluminum-tolerant phosphobacteria: Enterobacter sp. 198, Enterobacter sp. RJAL6, and Klebsiella sp. RCJ4. Cultivated under varying conditions, P deficiency upregulated P metabolism proteins while Al exposure downregulated iron-sulfur and heme-containing proteins and upregulated iron acquisition proteins. This demonstrated that Al influence on iron homeostasis and bacterial central metabolism. This study offers crucial insights into bacterial behavior in acidic soils, benefiting the development of bioinoculants for crops facing Al toxicity and P deficiency. This investigation marks the first proteomic study on the interaction between high Al and P deficiency in acid soils-adapted bacteria.

Effects of nutritional profile system and front labeling in food selection during purchases: a systematic review / Efecto de los sistemas de perfilado nutricional y etiquetado frontal en la selección de alimentos durante la compra: una revisión sistemática

Introduction. Nutritional profiling systems (NPS) are mainly used in front-end labeling policies in order to make the purchase and consumption choice conscious and healthy. Objetive. This study systematically reviewed evidence from interventions on the effect of NPS in the front-of- package on food purchases. Materials and methods. A bibliographic search was carried out in electronic sources from Medline, Elsevier, Scielo and Lilacs, of experimental studies and intervention between 2012 and 2022. A total of 14 articles were included in the review. They were analyzed according to the intervention modality used: 4 studies analyzed the effect of NPS in a real purchase situation and 10 evaluated purchase perception/intention. Results. According to the modality of intervention, the 6 studies that analyzed the NPS-warning system, all recorded healthier purchases compared to the control groups. While for the NPS-NutriScore, Health Star Rating and Multiple Traffic Lights were effective in the decision to purchase healthier foods, in 5 of 7 studies for the first NPS, in 4 of 7 for the second and in 4 of 8 for the third, compared with control groups. Conclusions. Findings of this study suggest that NPSs may be effective for healthy purchase choices, even so it is necessary to strengthen the system and policies with nutritional food education campaigns(AU)

Introducción. Los sistemas de perfilado nutricional (SPN) son utilizados principalmente en políticas de etiquetado frontal con la finalidad de que la elección de compra y consumo sea consciente y saludable. Objetivo. Este estudio revisó sistemáticamente la evidencia de las intervenciones sobre el efecto de SPN en el frente del paquete en las compras de alimentos. Materiales y métodos. Se realizó una búsqueda bibliográfica en fuentes electrónicas de Medline, Elsevier, Scielo y Lilacs, de estudios experimentales e intervenciones entre 2012 y 2022. Se incluyeron un total de 14 artículos en la revisión. Fueron analizados según la modalidad de intervención utilizada: 4 estudios analizaron el efecto de los SPN en una situación de compra real y 10 evaluaron percepción/intención de compra. Resultados. Según la modalidad de intervención, los 6 estudios que analizaron el SPN-sistema de advertencia, todos registraron compras más saludables en comparación con grupo controles. Mientras que para los SPN-NutriScore, Estrellas de Salud y Semáforo Tricolor Múltiple fueron efectivas en la decisión de compra de alimentos más saludables, en 5 de 7 estudios para el primer SPN, en 4 de 7 para el segundo y en 4 de 8 para el tercero, comparados con grupo controles. Conclusiones. Los hallazgos de este estudio sugieren que los SPN pueden ser efectivos para elecciones de compras saludables, aun así, es necesario reforzar el sistema y las políticas con campañas de educación alimentaria nutricional(AU)

Obesity Is Associated with Changes in Laboratory Biomarkers in Chilean Patients Hospitalized with COVID-19.

BACKGROUND AND AIMS: It is reported that patients with obesity are more frequently hospitalized for COVID-19, and evidence exists that obesity is a risk factor, regardless of other comorbidities. The objective of this study was to evaluate the association of obesity with changes in laboratory biomarkers in hospitalized Chilean patients. MATERIALS AND METHODS: A total of 202 hospitalized patients (71 with obesity and 131 without obesity) with a diagnosis of COVID-19 were included in the study. Demographic, clinical, and laboratory (days 1, 3, 7, 15) data were obtained. We performed a statistical analysis, assuming significance with a value of p < 0.05. RESULTS: Significant differences in chronic respiratory pathology are observed between patients with and without obesity. The inflammatory markers CPR, ferritin, NLR, and PLR are elevated during the evaluated period, while changes in leukocyte populations are present on day 1 (eosinophils) and day 3 (lymphocytes). Finally, a persistent elevation of D-dimer level is observed, presenting significant differences on day 7 between patients with and without obesity. Obesity had a positive correlation with admission to the critical patient unit, invasive mechanical ventilation, and length of hospital stay. CONCLUSION: Patients with obesity hospitalized for COVID-19 present marked elevations of inflammatory and hemostasis parameters, with a correlation between obesity, changes in laboratory biomarkers, and the risk of adverse clinical outcomes also observed.

Protist-Lactic Acid Bacteria Co-Culture as a Strategy to Bioaccumulate Polyunsaturated Fatty Acids in the Protist Aurantiochytrium sp. T66.

Thraustochytrids are aquatic unicellular protists organisms that represent an important reservoir of a wide range of bioactive compounds, such as essential polyunsaturated fatty acids (PUFAs) such as arachidonic acid (ARA), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), which are involved in the regulation of the immune system. In this study, we explore the use of co-cultures of Aurantiochytrium sp. and bacteria as a biotechnological tool capable of stimulating PUFA bioaccumulation. In particular, the co-culture of lactic acid bacteria and the protist Aurantiochytrium sp. T66 induce PUFA bioaccumulation, and the lipid profile was evaluated in cultures at different inoculation times, with two different strains of lactic acid bacteria capable of producing the tryptophan dependent auxins, and one strain of Azospirillum sp., as a reference for auxin production. Our results showed that the Lentilactobacillus kefiri K6.10 strain inoculated at 72 h gives the best PUFA content (30.89 mg g-1 biomass) measured at 144 h of culture, three times higher than the control (8.87 mg g-1 biomass). Co-culture can lead to the generation of complex biomasses with higher added value for developing aquafeed supplements.

Bioconversion of Cheese Whey and Food By-Products by Phaeodactylum tricornutum into Fucoxanthin and n-3 Lc-PUFA through a Biorefinery Approach.

This study investigates the potential of utilizing three food wastes: cheese whey (CW), beet molasses (BM), and corn steep liquor (CSL) as alternative nutrient sources for the cultivation of the diatom Phaeodactylum tricornutum, a promising source of polyunsaturated eicosapentaenoic acid (EPA) and the carotenoid fucoxanthin. The CW media tested did not significantly impact the growth rate of P. tricornutum; however, CW hydrolysate significantly enhances cell growth. BM in cultivation medium enhances biomass production and fucoxanthin yield. The optimization of the new food waste medium was conducted through the application of a response surface methodology (RSM) using hydrolyzed CW, BM, and CSL as factors. The results showed a significant positive impact of these factors (p < 0.005), with an optimized biomass yield of 2.35 g L-1 and a fucoxanthin yield of 3.64 mg L-1 using a medium composed of 33 mL L-1 of CW, 2.3 g L-1 of BM, and 2.24 g L-1 of CSL. The experimental results reported in this study showed that some food by-products from a biorefinery perspective could be utilized for the efficient production of fucoxanthin and other high-added-value products such as eicosapentaenoic acid (EPA).

Intermittent fasting for health care, a review / El ayuno intermitente, ¿un éxito o una desventaja para el cuidado de la salud?

The incidence of obesity and overweight in the world has been increasing in recent years due to poor diet and lack of physical activity; people suffering obesity and overweight, related with malnutrition due to excess, often resort to calorie restriction diets that are usually not very effective. In this context, intermittent fasting (IF) has become popular due to the possibilities for weight loss that it offers. This diet consists of alternating periods of fasting with unrestricted eating; however, its effectiveness and consequences are unknown to most users. This narrative review analyzes whether intermittent fasting contributes to the improvement of body and metabolic composition. The purpose of the review was to examine the available data on the contribution of intermittent fasting to the improvement of body and metabolic composition, in order to provide information and to define the parameters that condition safe achievement of its benefits. IF dieting triggers adaptive cell responses that cause a decrease in lipid oxidative stress markers in individuals with obesity and prediabetes. Metabolic alterations have been found to go hand in hand with the alteration of circadian rhythms; if IF contributes to this effect, it may assist in treating and preventing obesity and associated diseases. However, there are also disadvantages, such as the loss of lean muscle mass by wasting, and increased hypoglycemia(AU)

La incidencia de obesidad y sobrepeso en el mundo ha ido en aumento en los últimos años debido a la mala alimentación y la falta de actividad física; Las personas que padecen obesidad y sobrepeso, relacionadas con la desnutrición por exceso, suelen recurrir a dietas de restricción calórica que suelen ser poco efectivas. En este contexto, el ayuno intermitente (AI) se ha popularizado debido a las posibilidades de pérdida de peso que ofrece. Esta dieta consiste en alternar períodos de ayuno con alimentación sin restricciones; sin embargo, su eficacia y consecuencias son desconocidas para la mayoría de los usuarios. Esta revisión narrativa analiza si el ayuno intermitente contribuye a la mejora de la composición corporal y metabólica. El objetivo de la revisión fue examinar los datos disponibles sobre la contribución del ayuno intermitente a la mejora de la composición corporal y metabólica, con el fin de aportar información y definir los parámetros que condicionan la consecución segura de sus beneficios. Se ha encontrado que las alteraciones metabólicas van de la mano con la alteración de los ritmos circadianos; si AI contribuye a este efecto, puede ayudar a tratar y prevenir la obesidad y las enfermedades asociadas. Sin embargo, también existen desventajas, como la pérdida de masa muscular magra por atrofia y el aumento de la hipoglucemia(AU)

Eating Patterns in Children with Autism Spectrum Disorder.

The purpose of this research was to analyze the eating patterns of preschool- and school-aged children with ASD, as provided by their families, in the La Araucanía Region of Chile. It involved a cross-sectional study with 72 families with children diagnosed with ASD aged between 2 and 12 years old. Food selectivity, appetite, body mass index (BMI) and frequency of food consumption were studied. The research determined that 97.67% present food selectivity, corresponding to alterations in the frequency of consumption of specific food groups. Moreover, 93.06%, 90.28%, 80.56% and 62.50% of children in the study do not meet the daily recommendations for fruit, fish, water and vegetable consumption, respectively. Therefore, it is important for these findings to be considered when designing and carrying out educational interventions regarding food in families with children with ASD for greater assertiveness and effectiveness in improving health.

Obesity as a Risk Factor for Severe COVID-19 in Hospitalized Patients: Epidemiology and Potential Mechanisms.

SARS-CoV-2 infection is a global public health problem, causing significant morbidity and mortality. Evidence shows that obesity is a recognized risk factor for hospitalization, admission to critical care units, and the development of serious complications from COVID-19. This review analyzes the available epidemiological evidence that relates obesity to a higher risk of severity and mortality from COVID-19, examining the possible pathophysiological mechanisms that explain this phenomenon on a cellular and molecular level.

Food Trade for Specific Health Use FOSHU through Patents in LATAM: Relevant Aspects in International Law / Comercio de Alimentos para Uso Específico de Salud FOSHU a través de Patentes en LATAM: Aspectos Relevantes en el Derecho Internacional

Introduction: This article addresses the legal regulations for Foods for Specified Health Uses (FOSHU) in the main trade associations of Latin America (LATAM), based on the Codex Alimentarius system. Objective: The objective is to determine regulatory progress in the trade of FOSHU products. Material and methods: This study includes a review of the literature emanating from the databases from 2018 to 2022, according to the framework of three general food marketing regulations: food safety claims; inspection regulations, and food manufacturing and labeling. Results: The results reveal the absence of a specific legislation for FOSHU foods, as these are only mentioned in the area of nutrition. Conclusions: The legal framework in the trade of these products is based on jus cogens. Registration of industrial patents in the main member countries of LATAM trade associations can be facilitated through the Patent Prosecution Highway (PPH)(AU)

Introducción: El artículo aborda las regulaciones jurídicas en Alimentos para Uso Específico de Salud "FOSHU" en las principales asociaciones comerciales de América Latina (LATAM), basados en el sistema Codex Alimentarius. Objetivo: Determinar el avance regulatorio en la comercialización de productos FOSHU. Materiales y métodos: Se revisa la literatura emanada de las bases de datos desde el año 2018 al 2022, según el marco de tres regulaciones generales de comercialización de alimentos: las declaraciones de seguridad alimentaria; las regulaciones de inspecciones, las de manufacturas de alimentos y etiquetado. Resultados: Los resultados revelaron la ausencia de una legislación específica para alimentos FOSHU, siendo solo mencionados en el área de la nutrición. Conclusiones: El revestimiento jurídico en la comercialización de estos productos; se cimienta en el ius cogens. Las inscripciones de patentes industriales en los principales países miembros de las asociaciones comerciales en LATAM pueden facilitarse por la vía del Patent Prosecution Highway (PPH)(AU)

Clinical simulation with dramatization, a teaching-learning strategy for undergraduate students of nutrition and dietetics

At present, education in Health Sciences requires interaction with real patients, which is made more complex due to the need to ensure their health safety. For this reason, new teaching methodologies are now being implemented, which help to improve and protect safe care. Objective: This study was carried out using a quantitative approach with a non-experimental, descriptive design. Materials and Methods: The sample was non-probabilistic and consisted of 87 undergraduate students. A questionnaire was used, with 18 statements divided into 3 dimensions: dimension 1, simulation structure, with six questions reflecting aspects related to its implementation; dimension 2, learning, with seven questions related to aspects of effective communication, trust, learning and respect for diversity; dimension 3, feedback for learning, with five questions, including feedback by the teacher and the simulated patient, as well as their own views with regard to participating in another similar experience again. A five-point Likert scale was used. Results: The three dimensions studied, simulation structure, learning and feedback for learning, report a high level of positive perceptions. Conclusion: The simulation strategy is an educational tool in health-related careers that enhances the clinical competencies of the students as well as the relevant theoretical and practical skills and abilities in their learning process, promoting integration of the knowledge acquired in previous subjects(AU)

En la actualidad, la formación en Ciencias de la Salud requiere de la interacción con pacientes reales, lo que se hace más complejo por la necesidad de velar por la seguridad de su salud. Por ello, ahora se están implementando nuevas metodologías docentes que ayudan a mejorar y proteger la atención segura. Objetivo: Este estudio se llevó a cabo con un enfoque cuantitativo con un diseño no experimental, descriptivo. Materiales y métodos: La muestra fue no probabilística a conveniencia y estuvo conformada por 87 estudiantes de pregrado. Se utilizó un cuestionario, con 18 enunciados divididos en 3 dimensiones: dimensión 1, estructura de simulación, con seis preguntas que reflejan aspectos relacionados con su implementación; la dimensión 2, aprendizaje, con siete preguntas relacionadas con aspectos de comunicación efectiva, confianza, aprendizaje y respeto a la diversidad; dimensión 3, retroalimentación para el aprendizaje, con cinco preguntas, que incluye la retroalimentación del docente y del paciente simulado, así como sus propias opiniones con respecto a participar nuevamente en otra experiencia similar. Se utilizó una escala tipo Likert de cinco puntos. Resultados: Las tres dimensiones estudiadas, estructura de simulación, aprendizaje y retroalimentación para el aprendizaje, reportan un alto nivel de percepciones positivas. Conclusión: La estrategia de simulación es una herramienta educativa en carreras afines a la salud que potencia las competencias clínicas de los estudiantes, así como las destrezas y habilidades teóricas y prácticas pertinentes en su proceso de aprendizaje, favoreciendo la integración de los conocimientos adquiridos en materias anteriores(AU)

Weight stigma of nutrition and dietetics students towards people with obesity

ABSTRACT Weight bias is present in different scenarios, one of them is the area of health on the part of its professionals. For this reason, the aim of this descriptive, observational and cross-sectional study was to determine whether weight bias towards people with obesity was observed among students of the Nutrition and Dietetics career of the Catholic University of Temuco and to provide corrective measures to prevent the bias. The participants of this study were 94 nutrition and dietetics undergraduate students from different years of study. Students answered the GAMS 27-Obesity. According to the results obtained in this study, future nutritionists have a predisposition to weight bias towards people with obesity, this can have a negative impact on the care of these patients. Implementing corrective measures, during professional training, can prevent weight bias towards people with obesity by future professionals, thus improving their quality of care and positively impacting the health of these people.

RESUMEN El sesgo de peso está presente en diferentes escenarios, uno de ellos es el área de la salud por parte de sus profesionales. Por tal motivo el objetivo de este estudio observacional, descriptivo y transversal fue determinar si existe presencia de sesgo de peso hacia las personas con obesidad, por parte de estudiantes de la carrera de Nutrición y Dietética de la Universidad Católica de Temuco y brindar medidas correctivas para prevenir este sesgo. Los participantes de este estudio fueron 94 estudiantes de pregrado en nutrición y dietética, de diferentes generaciones a quienes se les aplicó el GAMS 27-Obesidad. Según los resultados obtenidos en este estudio, los futuros nutricionistas tienen una predisposición al sesgo de peso hacia las personas con obesidad, esto puede repercutir negativamente en el cuidado de estos pacientes. La implementación de medidas correctivas, durante la formación profesional, puede evitar el sesgo de peso hacia las personas con obesidad por parte de los futuros profesionales, mejorando así su calidad asistencial e impactando positivamente en la salud de estas personas.

Nutrition education intervention for children with cancer and their parents

ABSTRACT Pediatric cancer in Chile is the leading cause of death resulting from disease in children, with an incidence of 14.5 per 100,000 children under 15 years of age. Overweight or obesity can be a possible side effect of treatment, and parents are key agents in influencing child habits. In this study, an educational program on healthy eating was developed directed at parents of children with cancer with the aim of contributing positively to diet quality. Twelve children with cancer were involved in the research together with their parents/guardians. A nutritional evaluation was carried out considering weight, height, waist circumference and skin folds. Diet was analyzed based on a 24-hour dietary recall, a 3-day diet diary and a frequency consumption survey (initial/final). Six nutrition education sessions were carried out. The results show a high prevalence of overweight and abdominal obesity, along with a high intake of candy, pastry products and sugary beverages, coupled with a low intake of fruit, vegetables, fish and water. After conducting educational intervention, a decrease in the consumption of unhealthy foods and an increase in healthy foods was achieved. Children with cancer in our sample had high levels of overweight and obesity and unhealthy eating habits, which is consistent with the results of a large part of studies carried out in this population. This can, however, be positively modified by engaging them and their parents/guardians in nutrition education.

RESUMEN El cáncer pediátrico en Chile es la principal causa de muerte por enfermedad en los niños, y presenta una incidencia de 14,5 por 100.000 niños menores de 15 años. El sobrepeso o la obesidad pueden ser un posible efecto secundario del tratamiento, y en este escenario los padres/tutores son agentes clave para influir en los hábitos del menor. En este estudio se desarrolló un programa educativo sobre alimentación saludable dirigido a padres/tutores de niños con cáncer con el objetivo de contribuir positivamente a la calidad de su dieta. Doce niños con cáncer participaron en la investigación junto con sus padres/ tutores. Se realizó una evaluación nutricional considerando peso, talla, perímetro de cintura y pliegues cutáneos. La dieta se analizó en base a un recordatorio de 24 horas, un diario de dieta de 3 días y una encuesta de frecuencia de consumo (inicial/ final). Se llevaron a cabo seis sesiones de educación nutricional. Los resultados muestran una alta prevalencia de sobrepeso y obesidad abdominal, asociados una alta ingesta de dulces, productos de pastelería y bebidas azucaradas, junto con una baja ingesta de frutas, verduras, pescado y agua. Luego de realizar la intervención educativa, se logró una disminución en el consumo de alimentos poco saludables y un aumento en los alimentos saludables. Se concluye que los niños con cáncer presentan altos niveles de desnutrición por exceso y hábitos alimentarios poco saludables, lo que concuerda con los resultados de gran parte de los estudios realizados en esta población. Sin embargo, esto puede modificarse positivamente al involucrar a ellos y a sus padres/ tutores en la educación nutricional.

Engineering Multigenerational Host-Modulated Microbiota against Soilborne Pathogens in Response to Global Climate Change.

Crop migration caused by climatic events has favored the emergence of new soilborne diseases, resulting in the colonization of new niches (emerging infectious diseases, EIDs). Soilborne pathogens are extremely persistent in the environment. This is in large part due to their ability to reside in the soil for a long time, even without a host plant, using survival several strategies. In this regard, disease-suppressive soils, characterized by a low disease incidence due to the presence of antagonist microorganisms, can be an excellent opportunity for the study mechanisms of soil-induced immunity, which can be applied in the development of a new generation of bioinoculants. Therefore, here we review the main effects of climate change on crops and pathogens, as well as the potential use of soil-suppressive microbiota as a natural source of biocontrol agents. Based on results of previous studies, we also propose a strategy for the optimization of microbiota assemblages, selected using a host-mediated approach. This process involves an increase in and prevalence of specific taxa during the transition from a conducive to a suppressive soil. This strategy could be used as a model to engineer microbiota assemblages for pathogen suppression, as well as for the reduction of abiotic stresses created due to global climate change.

Impact of nutritional and physical activity interventions on the cognitive and academic achievement of schoolchildren

The objective of this review is to present the impact of nutritional education, physical activity and support network interventions on the nutritional status, cognitive and academic achievement of students under 18 years of age. According to the literature, multicomponent interventions that address diet, physical activity, and involve parents concluded to be more effective in combating obesity and enhancing academic achievement in young people. Therefore, the implementation of public policies that commit to intervene in a timely manner in the first stages of the life cycle, would have a considerably beneficial impact on health(AU)

El objetivo de esta revisión es dar a conocer el impacto de las intervenciones de educación nutricional, actividad física y redes de apoyo en el estado nutricional, rendimiento cognitivo y académico de estudiantes menores de 18 años. De acuerdo con la literatura, las intervenciones de carácter multicomponente que abordan alimentación, actividad física, e involucran a los padres concluyeron ser más efectivas para combatir la obesidad y potenciar el rendimiento académico en jóvenes. Por lo tanto, la implementación de políticas públicas que permitan intervenir de forma oportuna las primeras etapas del ciclo vital, tendrían un impacto considerablemente beneficioso para la salud(AU)

Antifungal Effects of Drimane Sesquiterpenoids Isolated from Drimys winteri against Gaeumannomyces graminis var. tritici.

Gaeumannomyces graminis var. tritici is a soilborne pathogen that causes "take-all" disease, affecting cereal roots. In wheat, G. graminis var. tritici is the most important biotic factor, causing around 30 to 50% losses of yield. Chemical control of this fungal disease is difficult because G. graminis var. tritici is able to reside for a long time in soils. Therefore, the development of environmentally friendly biotechnological strategies to diminish the incidence of soilborne diseases is highly desirable. Natural products are a promising strategy for biocontrol of plant pathogens. A special emphasis is on medicinal plants due to their reported fungitoxic effects. Drimys winteri (canelo) is a medicinal plant that is widely used by the Mapuche ethnic group from Chile due to its anti-inflammatory activity. In addition, inhibitory effects of canelo against phytopathogenic fungi and pest insects have been reported. In this study, we isolated, purified, and identified six drimane sesquiterpenoid compounds from canelo (drimenin, drimenol, polygodial, isodrimeninol, valdiviolide, and drimendiol). Then, we evaluated their antimicrobial effects against G. graminis var. tritici. Compounds were identified by comparing Fourier-transform infrared spectroscopy (FTIR) data and the retention time in thin-layer chromatography (TLC) with those of pure standards. The putative antagonistic effects were confirmed by assessing hyphal cell wall damage using confocal microscopy and lipid peroxidation. Here, we reported the high potential of drimane sesquiterpenoids as natural antifungals against G. graminis var. tritici. Polygodial and isodrimeninol were the most effective, with 50% lethal concentrations (LC50s) between 7 and 10 µg ml-1 and higher levels of fungal lipid peroxidation seen. Accordingly, natural sesquiterpenoids purified from canelo are biologically active against G. graminis var. tritici and could be used as natural biofungicides for sustainable agriculture.IMPORTANCE More than two billion tons of pesticides are used every year worldwide. An interesting sustainable alternative to control plant pathogens is the use of natural products obtained from plants, mainly medicinal plants that offer secondary metabolites important to human/animal health. In this study, we isolated and identified six pure drimane sesquiterpenoids obtained from the bark of Drimys winteri Additionally, we evaluated their antifungal activities against Gaeumannomyces graminis (the main biotic factor affecting cereal production, especially wheat) by assessing fungal cell wall damage and lipid peroxidation. The compounds obtained showed important antifungal properties against G. graminis var. tritici, mainly isodrimenol, which was the second-most-active compound after polygodial, with an LC50 against G. graminis var. tritici of around 9.5 µg ml-1 This information could be useful for the development of new natural or hemisynthetic antifungal agents against soilborne phytopathogens that could be used in green agriculture.

Occurrence of Soil Fungi in Antarctic Pristine Environments.

The presence of fungi in pristine Antarctic soils is of particular interest because of the diversity of this microbial group. However, the extreme conditions that coexist in Antarctica produce a strong selective pressure that could lead to the evolution of novel mechanisms for stress tolerance by indigenous microorganisms. For this reason, in recent years, research on cold-adapted microorganisms has increased, driven by their potential value for applications in biotechnology. Cold-adapted fungi, in particular, have become important sources for the discovery of novel bioactive secondary metabolites and enzymes. In this study, we studied the fungal community structure of 12 soil samples from Antarctic sites, including King George Island (including Collins Glacier), Deception Island and Robert Island. Culturable fungi were isolated and described according to their morphological and phenotypical characteristics, and the richness index was compared with soil chemical properties to describe the fungal community and associated environmental parameters. We isolated 54 fungal strains belonging to the following 19 genera: Penicillium, Pseudogymnoascus, Lambertella, Cadophora, Candida, Mortierella, Oxygenales, Geomyces, Vishniacozyma, Talaromyces, Rhizopus, Antarctomyces, Cosmospora, Tetracladium, Leptosphaeria, Lecanicillium, Thelebolus, Bjerkandera and an uncultured Zygomycete. The isolated fungi were comprised of 70% Ascomycota, 10% Zygomycota, 10% Basidiomycota, 5% Deuteromycota and 5% Mucoromycota, highlighting that most strains were associated with similar genera grown in cold environments. Among the culturable strains, 55% were psychrotrophic and 45% were psychrophilic, and most were Ascomycetes occurring in their teleomorph forms. Soils from the Collins Glacier showed less species richness and greater species dominance compared with the rest of the sites, whereas samples 4, 7, and 10 (from Fildes Bay, Coppermine Peninsula and Arctowski Station, respectively) showed greater species richness and less species dominance. Species richness was related to the C/N ratio, whereas species dominance was inversely related to C and N content. Thus, the structure of the fungal community was mainly related to soil chemical parameters more than sample location and altitude.

Microbial Community Composition in Take-All Suppressive Soils.

Gaeumannomyces graminis var. tritici (Ggt) is the main soilborne factor that affects wheat production around the world. Recently we reported the occurrence of six suppressive soils in monoculture areas from indigenous "Mapuche" communities, and evidenced that the suppression relied on the biotic component of those soils. Here, we compare the rhizosphere and endosphere microbial community structure (total bacteria, actinomycetes, total fungi, and ascomycetes) of wheat plants grown in suppressive and conducive soils. Our results suggested that Ggt suppression could be mediated mostly by bacterial endophytes, rather than rhizosphere microorganisms, since the community structure was similar in all suppressive soils as compared with conducive. Interestingly, we found that despite the lower incidence of take-all disease in suppressive soils, the Ggt concentration in roots was not significantly reduced in all suppressive soils compared to those growing in conducive soil. Therefore, the disease suppression is not always related to a reduction of the pathogen biomass. Furthermore, we isolated endophytic bacteria from wheat roots growing in suppressive soils. Among them we identified Serratia spp. and Enterobacter spp. able to inhibit Ggt growth in vitro. Since the disease, but not always pathogen amount, was reduced in the suppressive soils, we propose that take all disease suppressiveness is not only related to direct antagonism to the pathogen.

Understanding the Strategies to Overcome Phosphorus-Deficiency and Aluminum-Toxicity by Ryegrass Endophytic and Rhizosphere Phosphobacteria.

Phosphobacteria, secreting organic acids and phosphatases, usually favor plant performance in acidic soils by increasing phosphorus (P) availability and aluminum (Al) complexing. However, it is not well-known how P-deficiency and Al-toxicity affect the phosphobacteria physiology. Since P and Al problems often co-occur in acidic soils, we have therefore proposed the evaluation of the single and combined effects of P-deficiency and Al-toxicity on growth, organic acids secretion, malate dehydrogenase (mdh) gene expression, and phosphatase activity of five Al-tolerant phosphobacteria previously isolated from ryegrass. These phosphobacteria were identified as Klebsiella sp. RC3, Stenotrophomona sp. RC5, Klebsiella sp. RCJ4, Serratia sp. RCJ6, and Enterobacter sp. RJAL6. The strains were cultivated in mineral media modified to obtain (i) high P in absence of Al-toxicity, (ii) high P in presence of Al-toxicity, (iii) low P in absence of Al-toxicity, and (iv) low P in presence of Al-toxicity. High and low P were obtained by adding KH2PO4 at final concentration of 1.4 and 0.05 mM, respectively. To avoid Al precipitation, AlCl3 × 6H2O was previously complexed to citric acid (sole carbon source) in concentrations of 10 mM. The secreted organic acids were identified and quantified by HPLC, relative mdh gene expression was determined by qRT-PCR and phosphatase activity was colorimetrically determined using p-nitrophenyl phosphate as substrate. Our results revealed that although a higher secretion of all organic acids was achieved under P-deficiency, the patterns of organic acids secretion were variable and dependent on treatment and strain. The organic acid secretion is exacerbated when Al was added into media, particularly in the form of malic and citric acid. The mdh gene expression was significantly up-regulated by the strains RC3, RC5, and RCJ6 under P-deficiency and Al-toxicity. In general, Al-tolerant phosphobacteria under P deficiency increased both acid and alkaline phosphatase activity with respect to the control, which was deepened when Al was present. The knowledge of this bacterial behavior in vitro is important to understand and predict the behavior of phosphobacteria in vivo. This knowledge is essential to generate smart and efficient biofertilizers, based in Al-tolerant phosphobacteria which could be expansively used in acidic soils.