vol. 12 núm. 2 (2021)

Research gap: Information is often scattered and to date there is no systematic analysis that allows an accurate description of studies about PGPR, which represents a limitation in further experimental research developments. Purpose: Describe the main applications of PGPR in original research worldwide. Methodology: The systematic review was carried out in three multidisciplinary databases following the Cochrane and PRISMA recommendations. Completeness, reproducibility and quality assessment were guaranteed. The analyzes were based on frequencies and 95% confidence intervals for the proportions Results and conclusions: 2,525 studies were identified and only 160 met the selection protocol. The majority of studies are from India, the main microbial genera described were Bacillus, Pseudomonas and Enterobacter, the most investigated PGPR mechanisms were indolacetic acid production (AIA), phosphate solubilization, antagonism and siderophores production. The most frequent plant species in the studies were corn, tomato, wheat and rice, in which the main effects of the PGPR were related weight and length of the root and the plant in general. It is concluded that this review identified the genres of PGPR, mechanisms of action PGPR and plant species of greater frequency in the studies, useful variables to summarize the evidence in this field and identify the main lines of action in future research aimed at improving health, crop production and environmental sustainability.

Contextualization: Due to the importance of pomegranate among fruit species, studies on the physiology of its seeds and the production of seedlings are essential for the expansion of commercial orchards. Knowledge gap: With the portrayed importance of this crop and its use in various sectors, such as agro-industrial and pharmaceutical products, the development of continuous and straightforward propagation techniques that provide a uniform seedling development will provide favorable conditions for the cultivation and exploitation of the species, improving its use and boosting new research.  Purpose: To evaluate the effect of scarification and immersion in gibberellic acid on the dormancy of pomegranate seeds, aiming at accelerating the emergence and improving the initial growth of seedlings. Methodology: The sarcotesta was removed and the seeds were scarified. The treatments consisted of a scarified control, a non-scarified control (seeds with and without scarification), and seeds subjected to the concentrations of 500 mg L-1, 1,000 mg L-1, and 1,500 mg L-1 of GA3. The following variables were evaluated: initial emergence, emergence percentage, mean emergence time, leaf number, stem diameter, shoot length, root length, and total dry matter. Results and conclusions: The pomegranate cv. Valencian seeds do not have tegument-related dormancy. In order to favor the emergence percentage and the initial growth of pomegranate seedlings, mechanical scarification and immersion of the seeds in GA3 are dispensed. Scarification and immersion of pomegranate seeds in 500 mg L-1 of GA3 are recommended to produce seedlings in a shorter time.

Contextualization: Colombia is the fourth largest producer of livestock in Latin America, after Brazil, Argentina and Mexico, with approximately 22.5 million livestock, making livestock one of the most important activities in the country's economy, contributing 53% of the domestic product livestock; a growth of about a third has been seen in order to produce foods that provide an optimal source of protein of animal origin and meet the consumer’s needs.   Research gap: A serious problem that occurs in livestock production in Colombia is the high production costs and low productivity at the farm level, which has generated the need to look for high-quality nutritional alternatives that are economically profitable for the producer.    Purpose: The purpose of this research was to evaluate the nutritional and microbiological composition of multinutritional blocks made with bovinese and enriched with a BAL (lactic acid bacteria) preparation with a fermentation process, as a possible alternative for ruminant supplementation.   Methodology: The microbial preparation is based on a medium and fast acidification heterofermentative lactic acid bacteria (BAL) culture. In the elaboration of the multinutritional blocks, mineralized salt, bovine excreta, alfalfa flour, coffee bran, corn flour, cement, urea and molasses with different inclusion percentages were used; in addition, to T2 and T3 added a microbial preparation and the T3 had a fermentation process for 48 hours at room temperature. The variables evaluated were: Humidity (H), Dry Matter (DM), Crude Protein (PC), crude fiber (FC), detergent neutral fiber (NDF), detergent acid fiber (FDA) and microbiological analysis, using a block design completely random. Results and conclusions: There were significant statistical differences (P≤0.05) between T3 and the other treatments in the PC, FC, FDA and FDN obtaining the highest values, an inversely proportional behavior was evident between the MS and the H for the different treatments; the aerobic concentration for T3 was 80 × 102 CFU / g, in addition to the absence of Salmonella in T2 and T3. The inclusion of a microbial preparation and fermentation for 48h improves the nutritional parameters of the multi-nutritional blocks.

Contextualization: A large number of chemical products are used in industry and technological sectors, generating health risks for those who are exposed, and may induce alterations depending on the concentration, manipulation, exposure, and susceptibility of the worker. These chemical agents can produce a variety of irritating allergic, toxic and even carcinogenic effects.   Knowledeg gap: Ignorance of the danger added to the operating conditions of chemical carcinogenic chemicals that occur in the exercise of daily activities in the industry can affect human health.   Purpose: The objective of the study is to identify and classify the risk related to these chemical substances in a meat food processing plant in the department of Cauca (Colombia).   Methodology: In a first phase of diagnosis, an information search was carried out in specialized databases, in the second phase it was developed from the information collected through the inventory of chemical substances in the plant, which are distributed at different storage sites with potential exposure potential. To identify the chemical risk identification, a qualitative analysis is applied using the risk characterization criterion "international chemical control toolbox". Subsequently, a review of the regulations in force in Colombia related to the handling, applications and corresponding requirements of these substances was made, establishing necessary control and prevention measures for the chemical nature of these agents.   Results and conclusions: Through the inventory, 407 substances present in the plant were identified, of which 91% are classified as dangerous chemicals and 3% correspond to chemicals with a potential carcinogenic effect. The risk assessment took into account the combination of risk factors for health and potential exposure that determines the level of control desired, divided into four levels of approach (1, 2, 3, 4), with approach 4 being considered Special for being the most critical and most dangerous point. Finally, it was determined that the substances of greatest attention in the plant are: portland cement, COD solution B, Gasoline, Sikadur 32 Primer Comp B, Sikadur Panel Comp B, for being within the approach 4.

Contextualization: Citrus trees are one of the most cultivated tree species in the world. They are of great importance since their production is greater than that of any other fruit tree.   Knowledge gap: Despite the great demand for citrus fruits in Colombia, there is limited knowledge about the origin and genetic diversity. Likewise, molecular characterization studies of citrus varieties established in the work collection of the Universidad de los Llanos have not been carried out, which is of vital importance to implement conservation strategies and potential use of genetic resources.   Purpose: to evaluate the genetic diversity of four citrus varieties (Tangelo orange, Valencia orange, Arrayana mandarin and Castilla lemon), established at the University of the Llanos with seven ISSR primers.   Methodology: The molecular characterization was carried out in the Plant Biotechnology and Animal Reproduction and Genetics laboratories of the Universidad de los Llanos Universidad de los Llanos. A binary matrix of absence and presence was generated. The genetic similarity between the individuals was calculated using the coefficient of similarity of Nei and Li (1979). The cluster analysis was performed by the UPGMA method and a dendrogram was generated using the NTSYS statistical package, version 2.02 pc. The unbiased heterozygosity, the percentage of polymorphic loci, and the unbiased f statistic were estimated with a 95% confidence interval, using the TFPGA statistical package, version 1.3. Results and conclusions: A total of 80 bands were obtained, of which 86.25% were polymorphic. The average estimated heterozygosity for the total population was 0.29, which shows a moderate genetic diversity. The CGA and AG primers were the ones with the greatest contribution to the estimation of genetic polymorphism. Little genetic differentiation was found (Fst = 0.03). At a level of similarity of 0.42, seven groups were formed, with groups 1 and 2 being the ones that grouped the largest number of genotypes of the four species, being mostly Arrayana mandarin and Tangelo orange. The seven primers were significant for the estimation of genetic diversity in citrus fruits and constitute a tool with great potential for further improvement work in this species.

Contextualization: The locality of Suba, specifically the Tibabuyes Zonal Planning Unit (UPZ), corresponds to a sector of the city of Bogotá which, due to its unbalanced expansion process, has led people to settle illegally on Protected Areas such as the Juan Amarillo Wetland, the Conejera Wetland, and the Bogotá River Special Management Zone, which belong to the Main Ecological Structure and are exposed to natural phenomena such as flooding.    Knowledge Gap: the phenomenon of informal occupation has become a pattern that does not favor the sustainability of the city of Bogotá and affects the quality of life, poverty and a wide social problem that affects the inhabitants and that can generate important land occupation consequences for the country and significantly increase risk.   Purpose: to design a conceptual proposal to reduce the risk of flooding in UPZ Tibabuyes.   Methodology: a methodology focused on Participatory Action (PAR) was used, within which three research phases were established. where perception analyzes were carried out in the area according to the needs established by the water round, in which the threat could be categorized according to the flood scenarios, for this the evaluation parameters were determined (high, when the sheet of water is> 1.0 m and its speed is greater than 2.0 m / s), and the category (average, when the sheet of water is> 0.5 <1.0 m and its speed is between 1.5 to 2.0 m / s).    Results and conclusions: The action plan consisting of 17 strategies was determined, out of which 10 correspond to implemented strategies in the event of a high flood risk scenario, and the 7 complementary strategies should be used in the event of a medium risk scenario. flood. In both, the affected population, the requirements and technical activities to be developed are related, together with an estimated budget and its possible sources of financing.

Contextualization: The mung bean is widely cultivated in Asia and Brazil, it has emerged as an option for cultivation in the second crop in the Central West Brazil, especially rotation with grasses is intended; however, the uneven and slow emergence of mung bean seedlings can lead to delays in the development of the crop and impair the final stand.    Knowledge gap: Some of the conditions that affect the initial establishment of the crop are the sowing depth and the size of the seed. These factors are still under discussion in the scientific environment, especially for a culture recently introduced in Brazil.    Purpose: the objective was to evaluate the effect of seed size and sowing depth standardization on the performance of mung bean seedlings.    Methodology: The trial was conducted in a Red Latosol, with Aw climate, average annual rainfall of 1300 mm and bimodal distribution. The experimental design used was completely randomized, in a 2 × 3 factorial scheme with 8 replicates of 25 seeds, totaling 48 plots. The factors analyzed were two seed size (3 and 4 mm) and three sowing depths (1, 2 and 3 cm). The emergency speed index (ISE), non-emerged seedlings, normal seedlings, fresh mass, dry mass and seedling length were evaluated. The data were submitted to variance analysis and, when significant at 5% probability, a Tukey test was applied to compare the means of the factors under study.  Results and conclusions: It was verified that, when sown at 1 cm depth, the seeds of mung bean have lower ISE, however, they obtained a lower percentage of seedlings not relevant for the study, and a higher percentage of normal seedlings emerged than at a depth of 3 cm. Thus, the most recommended depth for the sowing of mung beans was 2 cm, regardless of the size of the seed used. The seed class of 4 mm allowed the development of seedlings with higher dry matter accumulation.

Contextualization: Neonatal diarrhea is a common pathology in calves, causing high mortality and decreased livestock productivity.   Knowledge gap: A proposed option for their control is the immunization of dams against enteropathogens, which has not been sufficiently researched in Colombia.   Purpose: The objective of this work was to determine indicators of passive immunity in bovine neonates, born of cows vaccinated with commercial bacterin against pneumoenteritis applied in the last third of gestation.   Methodology: Twenty-one crossbred pregnant cows were distributed in three groups: T1, control; T2, application of a dose of the biological 30 days prepartum, and T3 application of two doses at 30 and 15 days prepartum; a fourth T4 group for active immunity determination, of neonates vaccinated with bacterin at 24 hours of life. The experimental period for cows ranging from 30 days antepartum until calving, calves between 24 and 72 hours after birth.   Results and conclusions: In the calves, indicators of protein metabolism and immunoglobulins (Ig) were analyzed. Colostrum quality, five indicators of protein metabolism and cortisol as an immune modulator were analyzed in cows, they did not present significant statistical differences between treatments, with the exception of T3 in AST. In neonates IgA and IgG had no significant differences between treatments or for time. IgM and albumin had significant differences for treatments or time, while globulins and total proteins only for time. No effect of bacterin applications was evidenced and no failure was found in the transfer of passive immunity.

Contextualization: Lupinus bracteolaris is a heliophite species that vegetates low lands, open slopes and sandstone hills. Knowledge gap: Despite the high rusticity and potential for covering poor soils, there is still no information to assist in the analysis of its seeds. Purpose: To determine pre-germinative treatments, substrate, temperature, luminosity and water intake in the vigor of Lupinus bracteolaris seeds. Methodology: Fruits were collected from 20 matrix plants, then the seeds were processed and submitted to the following tests: pre-germinative methods (six treatments at 25°C); substrates and temperatures (sand and paper at 20, 25 and 30°C); photoblast test (white light, diffuse-green light and continuous dark under 20°C) and the imbibition curve (control and scarification between sandpaper under 20°C). Evaluations: percentage of germination and formed seedlings, germination speed index, average germination time and seedling formation, using a completely randomized design. Results and conclusions: According to the analyzed variables, the results showed superiority for the pre-germinative treatment between sandpapers for 20 seconds. In addition, the substrate paper germibox and the temperature of 20°C were the most suitable during seed germination. The seeds of Lupinus bracteolaris were classified as neutral-photoblastic and without dormancy.

Contextualization: Advancement in the Sensitivity of Analytical Techniques developed in recent decades contribute to identify and quantify the presence of various pollutants in the aquatic environment, within this group of pollutants we have the emerging pollutants (EP) which are mainly organic compounds present as personal care and hygiene products, antibiotics, hormones, plasticizers, drugs and other products that are dumped into water sources altering the balance of these ecosystems.   Knowledge gap: Several studies show that emerging pollutants may negatively affect aquatic life and human health. To date, in the city of Monteria and in the department of Córdoba, any investigations has been reported that allows evidence of the presence of emerging pollutants in surface water, for human and residual consumption.   Purpose: This study aimed to evaluate the presence of five common emerging pollutants: naproxen, ibuprofen, gemfibrozil, caffeine and triclosan in samples of water for human, residual and surface consumption collected in the north of Colombia, representing thus one of the first studies to report the presence of these compounds in water sources in this region.   Methodology: Solid phase extraction (SPE) was used for the analysis of the water samples; the detection and quantification were carried out by high efficiency liquid chromatography with a diode array detector and molecular fluorescence (HPLC-DAD-FLD).   Results and conclusions: Ibuprofen was the most frequently found compound in the water samples, opposite to triclosan, which was the least detected (2.25 µg / L), caffeine was found with a maximum of 43.38 µg/L, while concentrations of naproxen and ibuprofen were between 0.047 and 10.21 µg/L, which is an important health concern due to presence of these compounds in drinking waters. These results show the anthropogenic pressure exerted on the aquatic compartments, which could become an environmental problem that may affect the dynamics and ecosystem services. It was found that the water supply plants do not take into account the presence of these compounds in their purification systems, which could become a public health issue in the future. Ibuprofen was found most frequently in all three the water sources, in contrast to triclosan, which was the least frequently detected at low levels (2.25 µg / L), caffeine was found with a maximum of 43.38 µg/L, while naproxen and ibuprofen concentrations were between 0.047 and 10.21 µg/L. These results show the anthropogenic pressure exerted on the aquatic compartments, which could become an environmental problem in the future. At the same time, it shows that the water supply plants do not take into account the presence of these compounds in their purification systems; Although the concentrations reported are low, it does not indicate that they do not represent any type of risk

Contextualization: The species Hypericum perforatum is widely applied for the treatment of several diseases, mainly for depression. The plant is not native to Brazil, a country that has a high degree of the disease, being considered a public health problem. Knowledge gap: The establishment of the species in the country can provide greater economic and demand autonomy, presenting itself as a treatment with few or no side effect. Purpose: Evaluate the use of highly potentialized dilutions and the influence of the growing season on the vegetative growth and contents of bioactive compounds in Hypericum perforatum plants. Methodology: Experiments were performed in two seasons: Spring/Summer and Summer/Autumn. The experimental plot consisted of 12 plants, 4 repetitions, and 5 treatments consisting of homeopathic preparations of Kali carbonicum, Natrum muriaticum, Phosphorus, and Silicea terra at 12CH, and distilled water as control, summing up 48 plants per treatment. The height of the longest branch, number of branches, dry mass of the shoots and dark glands were evaluated, as well as the amounts of phenolic compounds. Results and conclusions: Homeopathic preparations affected differently H. perforatum plants over the cultivated seasons. In the Spring/Summer experiment, the Silicea terra treatment promoted plant growth, differing from Phosphorus, but not from other treatments. In the Summer/Autumn experiment, the homeopathies Kali carbonicum, Natrum Muriaticum and Phosphorus increased the vegetative growth in relation to control. The experiment carried out in the Spring/Summer showed the best results, increasing the growth and the number of branches and affording higher biomass yield. The formation of dark glands was not stimulated by the use of homeopathic preparations, however, the Spring/Summer experiment promoted higher averages. The hypericin compound was not detected in any sample of H. perforatum leaves. This suggests the need for an extended cultivation time to accumulate that naphthodianthrone compound in the dark glands.

Contextualización: Sustrato es todo el material poroso, que, asociado a una maceta, proporciona ancoraje y suficientes niveles de agua y oxígeno al desarrollo de las plantas. Vacío de conocimiento: Algunos materiales cuando adjuntados a la formulación suelen generar alteraciones en el producto final, las cuales pueden ser desventajosas, dependientes de su aplicación. Propósito del estudio: Evaluar la influencia del suelo mineral bajo sus características química y física, cuando utilizado cómo componente de sustrato para plantas. Metodología: Se empleó un argisol rojo distrófico típico, que se autoclavó, tamizó (malla 4,75 mm) y posteriormente se mezcló bajo diferentes proporciones (0, 25, 50, 75 e 100%) con turba de Sphagnum o polvo-de-coco (v/v). Las mezclas se sometieron a la caracterización física, química y biológica. Se empleó el diseño estadístico enteramente casualizado, con tres repeticiones por tratamiento. Los datos se sometieron al análisis de varianza y regresión polinomial (P < 0,05). Resultados y conclusiones: Al añadirse suelo en la formulación de los sustratos hubo disminución en la conductividad eléctrica y manutención del pH, además del aumento expresivo en las densidades húmeda y seca, y reducción en la porosidad total, espacio de aireación, disponibilidad y capacidad de retención de agua. Además, se encontraron hongos y nematodos en el suelo, que puede ser un inoculador de patógenos. Por lo tanto, el empleo de suelo mineral cómo componente de sustrato, además de generar formulaciones con características de cultivo inadecuadas, pudiendo influenciar negativamente el crecimiento y desarrollo vegetal, provoca daños ambientales debido a su extracción, conllevando a una producción insostenible a largo plazo.

Contextualization: Since the Kyoto protocol and the Paris Summit, the reduction of greenhouse gases, GHG, caused by anthropic activity, has become vitally important in the world, given the critical emission indicators with harmful effects on the climate.  Knowledge gap: Within this panorama, preliminary researches does not agree on which fuel generates the lowest CO2 emissions: diesel or biodiesel.  Purpose: For this reason, and seeking to provide information to propose sustainable energy alternatives from substitutes for fossil fuels, it was necessary to quantify and evaluate CO2 emissions from diesel engines, for which purpose, the experiment was carried out with the purpose of use commercial diesel  and biodiesel, and determine their CO2 emissions, for this a compression engine from a power plant was used, with fixed factors such as the amount of fuel to be used established at 100 grams.  Methodology: The experiment was statistically supported by a factorial design of two factors: type of diesel with two levels and power generated with three levels, and the joint effect that these factors produce on CO2 emission was determined. For this, the motor was subjected to the execution of three jobs related to three generated powers: 0.5kW-1.0kW-1.5kW; which caused for each power level, different flows or consumption of fuel and air, and different CO2 emissions.  Results and conclusions: The results indicate that: using any fuel, the air/fuel ratio is lower and the molar fraction of CO2 is higher when more work is done; the experiment showed that the molar fraction of B10 is greater than that of B100: 0,15 and 0,13, respectively, so it cannot be generalized that the higher CO2 emission is caused by commercial diesel. The greater or lesser emission depends on the chemical composition of the fuel.