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Wetlands provide numerous ecosystem services to the environment, such as nutrient removal and storage. The aim of this work is to evaluate the nutrient dynamics in different sectors within wetland systems in the south of the Samborombón Bay (Argentina) based on hydrological and/or anthropogenic variations. For this purpose, the hydrological features of the wetland were defined through the analysis of satellite images, precipitation and tidal data, and field surveys. Three sectors were identified in the wetland: one with tidal influence, another which is dependent on rainfall, and another that receives inputs from rainfall and from a sewage effluent treatment plant. In order to analyze the nutrient dynamics, samples of surface water, groundwater, and sediments were collected from these sectors. Measurements of pH and electrical conductivity were determined in situ in water samples, while the concentration of inorganic forms of phosphorus and nitrogen, soluble reactive silica, and organic carbon were determined through laboratory analysis. Also, bioavailable phosphorus, organic matter, pH, and electrical conductivity were determined in the sediment samples collected. Statistical analysis of the data reveals differences between the sectors and allows the interpretation of the dynamics of the studied components in the wetland. Electrical conductivity distinguishes the intertidal sectors of the wetland while components associated with P and N discriminate the sectors with inputs from the sewage effluent treatment plant. On the other hand, soluble reactive silica, organic carbon, and organic matter do not seem to be influenced by the tide or effluent discharge. This study demonstrates that the studied wetland works as a nutrient retention area, providing ecosystem services to local inhabitants. Although these services can be utilized, they require a continuous monitoring over time to provide an early warning in case the variations in P and N cycles could lead to eutrophication or wetland degradation.

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This research aims to identify critical contamination points by nutrients, their possible origin (point and nonpoint sources), their spatial distribution, and possible attenuation by natural and anthropogenic processes. The study area is the Velhas River Basin, located in the Southeast Region of Brazil (17.0°-20.5° S; 43.5°-45.0°W). A historical series of water quality monitoring, land cover map, demographic and agricultural censuses, sewage treatment diagnostics, and local hydrographic networks were used to achieve the objectives. In addition, the regions were divided into incremental areas, enabling individualized analyses of each sub-basin. Descriptive statistics, seasonality, categorized data tests, agglomerative hierarchical cluster analysis, and principal component analysis were used. There was a significant contribution of nutrients in the most important urban agglomeration of the basin, resulting in peak concentrations measured at that place. Although the values were reduced by the mouth (650 km), the percentage of legislation violations remained high. The effects of punctual contamination were intensified by the low percentage of treated sewage in the basin, the absence of adequate treatment technologies to remove nutrients, and the disorderly urbanization. Furthermore, it was estimated that the nutrient load from animal husbandry is approximately 75% of the load from domestic effluents due to the high number of cattle in the basin and the low percentage of forests.

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Cadmium (Cd) is one of the most toxic heavy metals for human health. It can be present in multiple food products, including cocoa cultivated in regions with high soil Cd concentrations. A strategy to minimize Cd uptake by cacao trees is using cadmium-tolerant bacteria (CdtB) and filamentous fungi (CdtF) to reduce Cd availability in soils. We isolated culturable CdtB and CdtF from different locations in a cocoa-producing region in central Colombia. A total of 42 CdtB and 30 CdtF morphotypes were isolated from locations with varying natural Cd concentrations. In vitro characterizations showed that in addition to their resistance to Cd, bacteria and fungi are involved in the nutrient cycling of N, P, and C in the soil. Bacterial morphotypes from genera Pseudomonas and Burkholderia grew in concentrations up to 140 mg kg-1 Cd. Among the isolated fungi, P. igniaria, Metarhizium sp., and Annulohypoxylon sp. were the most resistant, with the highest average Cd bioaccumulation, Cd remotion, and tolerance. We present new information about the native culturable bacterial morphotypes associated with cacao plants and, to the best of our knowledge, this is the first report of Cd-TF associated with cacao crops. Our results expand the knowledge about culturable CdtB and CdtF in cacao-cultivated soils and their interaction with key soil elements, with the potential to develop integrated soil management strategies.

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The use of phosphate-solubilizing fungi in coffee cultivation is an alternative to the use of traditional fertilizers. The objective of this study was to analyze the mechanisms involved in the phosphorus solubilization of fungal strains and to evaluate the effect of a phosphate-solubilizing strain on coffee plants. For this, phosphorus-solubilizing fungal strains were selected for evaluation of their solubilization potential and phosphatase activity. Coffee plants were inoculated in the field with a phosphate-solubilizing strain, and the soil and foliar soluble phosphorus contents, as well as coffee bean yield, were quantified. Of the 151 strains analyzed, Sagenomella diversispora, Penicillium waksmanii, and Penicillium brevicompactum showed the highest solubilization. Aspergillus niger and P. waksmanii presented the highest soluble phosphorus values; however, P. brevicompactum showed the highest phosphatase activity. The P. brevicompactum strain inoculated on the coffee plants did not favor the foliar phosphorus content but increased the soil soluble phosphorus content in two of the coffee plantations. The plants inoculated with the phosphate-solubilizing strain showed an increase in coffee bean weight on all plantations, although this increase was only significant in two of the three selected coffee plantations.

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The aim of present study was to investigate the effect of phytase supplementation on growth performance, mineral digestibility, and tibia calcium and phosphorous in broilers fed low phosphorus diets. Three hundred broiler chicks were allotted to six different treatments with five replicates each (10 chicks/replicate). T1: Control, 0.5% available phosphorus (Av.P); T2: 0.35P, 0.35% Av.P; T3: 0.20P, 0.20% Av.P; T4: 0.35P-1Phy, diet 0.35P + 1000FTU/kg phytase; T5: 0.20P-2Phy, diet 0.20P + 2000 ftu/kg phytase; T6: 0.20P-3Phy, diet 0.20P + 3000 ftu/kg phytase. Feed intake and weight gain were higher (p=0.001) in broilers fed phytase supplemented diets. Feed conversion ratio was better (p<0.01) in the 0.35P-1Phy than in the others. Calcium and P digestibility was higher (p<0.05) in the 0.35P-1Phy than the 0.35P, 0.20P and 0.20P-2Phy, groups. The highest (p<0.05) tibia ash was observed in the 0.35P and 0.35P-1Phy groups rather than the 0.20P at 21st day, while at 33rd day it was higher (p<0.05) in the control than in 0.20P. At 21st day, tibia Ca content was higher (p<0.05) in the 0.35P-1Phy group as compared to 0.20P and 0.35P, while at 33rd day, tibia Ca content in the control and 0.20P-2Phy groups was higher (p<0.05) than that of 0.20P and 0.35P. Furthermore, tibia P content was higher (p<0.05) in all phytase supplemented groups. It could be concluded that dietary available phosphorus at 0.35% with phytase addition at 1000 FTU/kg reduces the cost per unit weight gain by 9.17%, with positive effects on growth performance.(AU)

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El cultivo de banano en el Urabá Antioqueño viene presentando disminución en los rendimientos, lo que exige la búsqueda de alternativas para incrementar o mantener la producción actual, entre las cuales, se encuentra el aumento en la proporción de fertilizantes inorgánicos, conllevando a sobrecostos y problemas ambientales. En vista de esta situación, se ha generado un interés por el uso de biofertilizantes, como el caso de las micorrizas (HFM), con las que se han demostrado beneficios al sistema suelo-planta. El objetivo de esta investigación fue evaluar el efecto de los HFM con la disminución de la dosis fosforada en el clon de banano Valery, en un sistema de alta densidad, bajo condiciones edafoclimáticas de Apartadó-Antioquia. Para ello, en los tratamientos, al momento de la siembra, se realizaron inoculaciones de 100 g de HFM comercial con 5 dosis de fósforo, que correspondieron a: 0, 25, 50, 75 y 100 kg*ha-1. Se midieron variables morfológicas, rendimiento y simbiosis micorrízica. El diseño experimental fue completamente al azar, con 3 repeticiones; cada unidad experimental estuvo constituida por 10 plantas contenidas en 5 sitios. La información se procesó con el programa estadístico SAS 9.1, se obtuvo el análisis de varianza y una prueba de comparación de medias (Tukey), con un nivel de significancia del 95 %. No se encontraron diferencias significativas en las variables morfológicas, pero sí en las variables productivas, siendo el tratamiento HFM + 50 kg P2O5*ha-1 el de mejor resultado y, además, presentó el mayor porcentaje de colonización micorrízica, con 59,5 %.

The banana crop in Uraba Antioqueño has been presenting a decrease in the yields, which requires the search for alternatives to increase or maintain current production, among which is the increase in the proportion of inorganic fertilizers leading to cost overruns and environmental problems. In view of this situation, there has been a growing interest in the use of biofertilizers such as mycorrhiza (HFM) with which multiple benefits to the soil-plant system have been demonstrated. The objective of this research was to evaluate the effect of HFM with the reduction of phosphorus dose in the Valery banana clone under a high-density system under edaphoclimatic conditions of Apartado-Antioquia. For this purpose, 100 g of commercial HFM were inoculated with 5 doses of phosphorus at time of sowing, corresponding to: 0, 25, 50, 75 and 100 kg*ha-1. Morphological variables, performance and mycorrhizal symbiosis were measured. The experimental design was completely random with 3 repetitions, each experimental unit was made up of 10 plants contained in 5 sites. The information was processed with the statistical program SAS 9.1, variance analysis was obtained and a mean comparison test (Tukey) with a significance level of 95 %. No significant differences were found in the morphological variables, but in the productive variables, the HFM + 50 Kg P2O5*ha-1 treatment was the best and also presented the highest percentage of mycorrhizal colonization with 59.5 %.

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The continuous increase in the consumption of natural resources requires different solutions directed to the recovery and recycling of different materials and products, including the nutrients used as fertilizers for food production. In this context, this research assessed the feasibility of using landfill leachate as a source of nutrients for the growth of maize. Leachate was treated to precipitate struvite, a rich magnesium, phosphate, and ammonium mineral that can be applied directly as fertilizer. It was used for the growth of maize, which was sowed in three different parcels. A commercial DAP + urea mixture was used to compare, and non-fertilized parcels were used as controls. Struvite was successfully obtained and applied in the fields. A marginal higher maize yield was achieved in two sites when using struvite (6.36% and 2.16%) compared to the commercial fertilizer, even if it was applied in a lower dose to weather conditions. An increase in N and Mg in soil could be observed, which allowed for the assimilation of nutrients in the plants. Concerning safety, the use of struvite did not produce the transfer of heavy metals or pathogens to the soil or plants. This research shows a promising way of dealing with leachate, which could be attractive in countries where organic waste is buried in landfills.

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Aerobic granular sludge (AGS) has been considered a breakthrough within the wastewater treatment sector. However, the long reactor start-up for the formation of granules is challenging and may hinder the spread of this technology. To circumvent this obstacle, inoculation of the reactors with pre-formed granules from existing plants is an interesting approach. In this context, issues related to biomass storage becomes very relevant. In this study, reactivation of aerobic granular biomass after storage was evaluated in a sequencing batch reactor (SBR) designed for achieving simultaneous organic matter, nitrogen and phosphorus removal. Two different scenarios, short (40 days) and long (180 days) storage periods, were assessed, and their influence on the granules physical properties and bioactivity was addressed. The results revealed that the granules stored for a shorter period showed higher resistance to breakage and underwent smooth color changes. On the other hand, the biomass stored for a longer period acquired a dark color and was more susceptible to disruption during reactivation. The granules stored for 6 months become swollen and exhibited an irregular morphology and fluffy structure within the first days of reactivation. Consequently, their settling properties were adversely affected, and some parameters such as the food-to-microorganism ratio had to be adjusted to prevent granules disintegration. Regarding the bioactivity of important microbial functional groups, COD removal was rapidly restored within a few days of SBR operation with the biomass stored for a shorter period. However, it took longer for the biomass stored for 180 days to reach the same performance observed for the granules stored for 40 days. A similar trend is valid for nitrification. In the experiments with sludge stored for a longer time, it took almost twice as long to reach effluent ammonium concentrations lower than 1 mg NH4+-N L-1 compared to the test using biomass stored for 40 days. Phosphate removal was strongly affected by biomass storage, especially after 180 days of inactivity, a condition found to be detrimental for polyphosphate-accumulating organisms. Finally, cycle tests were also conducted to assess substrate conversion rates for comparison between different trials and evaluate the influence of temperature (10-35 °C) on nitrification and phosphate removal rates.

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Reaction of heterometallic cubane-type cluster complexes-[Mo3{Pd(dba)}S4Cl3(dbbpy)3]PF6, [Mo3{Pd(tu)}S4Cl3(dbbpy)3]Cl and [Mo3{Pd(dba)}S4(acac)3(py)3]PF6, where dba-dibenzylideneacetone, dbbpy-4,4'-di-tert-butyl-2,2'-bipyridine, tu-thiourea, acac-acetylacetonate, py-pyridine, with white phosphorus (P4) in the presence of water leads to the formation of phosphorous acid H3PO3 as the major product. The crucial role of the Pd atom in the cluster core {Mo3PdS4} has been established in the hydrolytic activation of P4 molecule. The main intermediate of the process, the cluster complex [Mo3{PdP(OH)3}S4Cl3(dbbpy)3]+ with coordinated P(OH)3 molecule and phosphine PH3, have been detected by 31P NMR spectroscopy in the reaction mixture.

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La deteccion de trastornos metabolicos minerales puede explicar diversas anomalias fisiologicas que exigen para su interpretacion la comparacion con valores de referencia validados. El objetivo de este trabajo fue la determinacion de valores de referencia en la poblacion infantil uruguaya, de los analitos sodio, potasio, calcio, magnesio, fosforo y urato relacionados con la creatinina en muestras de la segunda miccion de la manana en 470 escolares (240 ninas y 230 ninos) con edades comprendidas entre 7 y 12 anos. Las medianas obtenidas fueron: Na/Crea: 139 mmol/g, K/Crea: 78 mmol/g, Ca/Crea: 77 mg/g, Mg/Crea: 71 mg/g, P/Crea: 500 mg/g, Ur/Crea: 554 mg/g, Crea: 117 mg/dL. A excepcion de los cocientes Na/Crea y K/Crea se encontro una disminucion de la excrecion de estos analitos con la edad, independientemente del sexo. Los valores obtenidos resultaron ser analogos a los de otras poblaciones con tipo de alimentacion similar.

The detection of mineral metabolic disorders can explain several pathologies which require the comparison with reference values for their interpretation. The aim of this study was to determine the reference values of 470 Uruguayan school children with ages between 7 and 12 for sodium, potassium, calcium, magnesium, phosporous and urate and their relationship with creatinine in urine samples of the second urination of the morning. The median obtained were: Na/Crea: 139 mmol/g, K/Crea: 78 mmol/g, Ca/Crea: 77 mg/g, Mg/Crea: 71 mg/g, P/Crea: 500 mg/g, Ur/Crea: 554 mg/g, Crea: 117 mg/dL. A diminishment of excretion with the age was found, regardless the sex, except for Na/Crea and K/Crea. The values obtained were similar to those of others populations with a similar diet.

A detecção de distúrbios metabólicos minerais pode explicar várias anomalias fisiológicas, que exigem a comparação com valores de referência validados para serem interpretados. O objetivo deste estudo foi determinar valores de referência na população infantil uruguaia, dos analitos sódio, potássio, cálcio, magnésio, fósforo e urato relacionados com a creatinina em amostras da segunda micção da manhã em 470 alunos (240 meninas e 230 meninos) com idades entre 7 e 12 anos. As medianas obtidas foram: Na/Crea: 139 mmol/g, K/Crea: 78 mmol/g, Ca/Crea: 77 mg/g, Mg/Crea: 71 mg/g, P/Crea: 500 mg/g, Ur/Crea: 554 mg/g, Crea: 117 mg/dL. Com exceção dos quocientes Na/Crea e K/Crea, foi encontrada uma diminuição na excreção destes analitos com a idade independentemente do sexo. Os valores obtidos foram análogos aos de outras populações com um tipo similar de dieta.

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Several universal genomic traits affect trade-offs in the capacity, cost, and efficiency of the biochemical information processing that underpins metabolism and reproduction. We analyzed the role of these traits in mediating the responses of a planktonic microbial community to nutrient enrichment in an oligotrophic, phosphorus-deficient pond in Cuatro Ciénegas, Mexico. This is one of the first whole-ecosystem experiments to involve replicated metagenomic assessment. Mean bacterial genome size, GC content, total number of tRNA genes, total number of rRNA genes, and codon usage bias in ribosomal protein sequences were all higher in the fertilized treatment, as predicted on the basis of the assumption that oligotrophy favors lower information-processing costs whereas copiotrophy favors higher processing rates. Contrasting changes in trait variances also suggested differences between traits in mediating assembly under copiotrophic versus oligotrophic conditions. Trade-offs in information-processing traits are apparently sufficiently pronounced to play a role in community assembly because the major components of metabolism-information, energy, and nutrient requirements-are fine-tuned to an organism's growth and trophic strategy.

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Discharge of effluents loaded with phosphorus (P) from anthropogenic activities constitutes serious eutrophication risks in marine and terrestrial ecosystems, including mangroves. Three mangroves in NE-Brazil were studied to evaluate the impact of P-rich-effluents from shrimp farming and domestic sewage, in relation to a control area (natural mangrove). Soil phosphorus fractionation and water chemical analysis were performed to assess potential pollution. We observed the most labile P forms increased gradually and significantly from control to sewage to shrimp farm impacted mangroves as observed by increasingly dissolved orthophosphate (PO43-) content in water and the exchangeable/soluble P (Exch-P) extracted from soils, which is supported by the discriminant analysis. Exch-P results were correlated to Humic-Acid-P, which can release more labile P forms when mineralized. Our results demonstrate a substantial impact of aquiculture and sewage effluents in mangroves at both organic and inorganic P fractions, raising important concerns regarding pollution for these marine ecosystems.

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Nutrient concentrations in tree biomass components may vary with the component considered, age and genetic material and its measurement is important to understand forestry nutrient management. Due to it, above ground biomass production and nutrient accumulation and its potential removal through thinning in two species of five-year-old Eucalyptus with were evaluated in the southern of Brazil. Treatments were arranged in a randomized block design with three replications in a 2 x 4 factorial scheme, being 2 species (E. grandis and E. urophylla) and four diametric classes (C1: 3.0 - 8.8; C2: 8.9 - 14.7; C3: 14.8 - 20.6; C4: 20.7 - 26.5 cm). Average annual accumulation of dry matter in both species was of 16.9 Mg ha-¹. Biomass was mainly allocated in the stem (wood and bark). Trees’ canopy (branches and leaves) represent the smallest fractions, with only 14,3% of the total biomass. E. grandis showed highest values of wood and leaf compartments. The highest content of N and K were found in the leaves, with N levels of 33.2 and 30.5 g.Kg-¹ respectively to E. grandis and E. urophylla. Trees bark represent an important Ca and Mg reserve to the development of the plant, with values of 18.02 and 3.24 g.kg-¹ respectively. The average concentration of Ca, N, K, Mg and P in the total biomass of the two species was of 528, 305, 200, 128 and 30 kg ha-¹.

As concentrações de nutrientes nos componentes da biomassa arbórea podem variar em função do componente, da idade da plantação e o material genético, e sua mensuração é importante para entender o manejo florestal de nutrientes do solo. A produção de biomassa da parte aérea, o acúmulo de nutrientes e o seu potencial de remoção em duas espécies de Eucalyptus com cinco anos de idade foram avaliados no sul do Brasil. Os tratamentos foram dispostos em delineamento de blocos casualizados com três repetições, em esquema fatorial 2 x 4, sendo duas espécies (E. grandis e E. urophylla) e quatro classes diamétricas (C1: 3,0 - 8,8; C2: 8,9 - 14,7; C3: 14,8 - 20,6; C4: 20,7 - 26,5 cm). O acúmulo médio anual de matéria seca em ambas as espécies foi de 16,9 Mg ha-¹. A biomassa foi alocada principalmente no caule (madeira e casca). O dossel das árvores (ramos e folhas) representa as menores frações, com apenas 14,3% da biomassa total. E. grandis apresentou maiores valores de madeira e compartimentos foliares. Os maiores teores de N e K foram encontrados nas folhas, com níveis de N de 33,2 e 30,5 g.Kg-¹, respectivamente, para E. grandis e E. urophylla. A casca das árvores representa uma importante reserva de Ca e Mg para o desenvolvimento da planta, com valores de 18,02 e 3,24 g.kg-¹, respectivamente. As concentrações médias de Ca, N, K, Mg e P na biomassa total das duas espécies foram de 528, 305, 200, 128 e 30 kg ha-¹.

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Nutrient concentrations in tree biomass components may vary with the component considered, age and genetic material and its measurement is important to understand forestry nutrient management. Due to it, above ground biomass production and nutrient accumulation and its potential removal through thinning in two species of five-year-old Eucalyptus with were evaluated in the southern of Brazil. Treatments were arranged in a randomized block design with three replications in a 2 x 4 factorial scheme, being 2 species (E. grandis and E. urophylla) and four diametric classes (C1: 3.0 - 8.8; C2: 8.9 - 14.7; C3: 14.8 - 20.6; C4: 20.7 - 26.5 cm). Average annual accumulation of dry matter in both species was of 16.9 Mg ha-¹. Biomass was mainly allocated in the stem (wood and bark). Trees canopy (branches and leaves) represent the smallest fractions, with only 14,3% of the total biomass. E. grandis showed highest values of wood and leaf compartments. The highest content of N and K were found in the leaves, with N levels of 33.2 and 30.5 g.Kg-¹ respectively to E. grandis and E. urophylla. Trees bark represent an important Ca and Mg reserve to the development of the plant, with values of 18.02 and 3.24 g.kg-¹ respectively. The average concentration of Ca, N, K, Mg and P in the total biomass of the two species was of 528, 305, 200, 128 and 30 kg ha-¹.(AU)

As concentrações de nutrientes nos componentes da biomassa arbórea podem variar em função do componente, da idade da plantação e o material genético, e sua mensuração é importante para entender o manejo florestal de nutrientes do solo. A produção de biomassa da parte aérea, o acúmulo de nutrientes e o seu potencial de remoção em duas espécies de Eucalyptus com cinco anos de idade foram avaliados no sul do Brasil. Os tratamentos foram dispostos em delineamento de blocos casualizados com três repetições, em esquema fatorial 2 x 4, sendo duas espécies (E. grandis e E. urophylla) e quatro classes diamétricas (C1: 3,0 - 8,8; C2: 8,9 - 14,7; C3: 14,8 - 20,6; C4: 20,7 - 26,5 cm). O acúmulo médio anual de matéria seca em ambas as espécies foi de 16,9 Mg ha-¹. A biomassa foi alocada principalmente no caule (madeira e casca). O dossel das árvores (ramos e folhas) representa as menores frações, com apenas 14,3% da biomassa total. E. grandis apresentou maiores valores de madeira e compartimentos foliares. Os maiores teores de N e K foram encontrados nas folhas, com níveis de N de 33,2 e 30,5 g.Kg-¹, respectivamente, para E. grandis e E. urophylla. A casca das árvores representa uma importante reserva de Ca e Mg para o desenvolvimento da planta, com valores de 18,02 e 3,24 g.kg-¹, respectivamente. As concentrações médias de Ca, N, K, Mg e P na biomassa total das duas espécies foram de 528, 305, 200, 128 e 30 kg ha-¹.(AU)

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Watershed studies that account for nutrient loadings are crucial for suitable river basin and estuarine management. This study aims to contribute to the environmental planning and decision making regarding nitrogen and phosphorus loadings for the watershed of the Vitória Bay Estuarine System (VBES; 1925 km2) in southeast Brazil. Here, we estimate that the VBES had annual loadings (in 2016) from ten tributary river basins of 5480 and 10,784 t for P and N, respectively, based on emission factors for natural and anthropogenic sources. The main contribution sources were related to livestock farming (4801 t of P and 8000 t of N) and domestic wastewater (492 t of P and 1706 t of N). However, urban loadings have higher expressions when considering the input by watershed area (0.25 and 0.87 t km-2 year-1 of P and N yields, respectively), which are mainly due to wastewater since 70% of the sewage is untreated. Urban emissions play a prominent role and have a tendency to be aggravated due to Brazilian population growth (0.8% annual rate). If the current wastewater emissions continue, P and N loadings will likely increase by 1.316% to totals of 713 and 2474 t year-1 in 2050 for P and N, respectively. Considering that the wastewater tertiary treatment cost is US$ 0.50 m-3, and that in the future 70% of all wastewater will be collected, the P and N loadings will drop to 18.4 and 424.1 t year-1, respectively, with a treatment cost of 25 million USD year-1. The model holds well for non-regulated watersheds. However, for regulated basins, such as the Santa Maria de Vitória, the model overestimates the loadings mainly due to the damming systems in these watersheds (accounting for 49% retention of P and 0.13% retention of N).

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This study was aimed to investigate the effect of bio-organic phosphate either alone or in combination with phosphorus solubilizing bacteria strain (Bacillus MWT-14) on the growth and productivity of two wheat cultivars (Galaxy-2013 and Punjab-2011) along with recommended (150-100NPkgha-1) and half dose (75-50NPkgha-1) of fertilizers. The combined application of bio-organic phosphate and the phosphorous solubilizing bacteria strain at either fertilizer level significantly improved the growth, yield parameters and productivity of both wheat cultivars compared to non-inoculated control treatments. The cultivar Punjab-2011 produced the higher chlorophyll contents, crop growth rate, and the straw yield at half dose of NP fertilizer; while Galaxy-2013, with the combined application of bio-organic phosphate and phosphorous solubilizing bacteria under recommended NP fertilizer dose. Combined over both NP fertilizer levels, the combined use of bio-organic phosphate and phosphorous solubilizing bacteria enhanced the grain yield of cultivar Galaxy-2013 by 54.3% and that of cultivar Punjab-2011 by 83.3%. The combined application of bio-organic phosphate and phosphorous solubilizing bacteria also increased the population of phosphorous solubilizing bacteria, the soil organic matter and phosphorous contents in the soil. In conclusion, the combined application of bio-organic phosphate and phosphorous solubilizing bacteria offers an eco-friendly option to harvest the better wheat yield with low fertilizer input under arid climate.

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The aim of this work was to study Cr, Ni, Zn, and P bioaccumulation in different compartments of Typha domingensis plants and sediment in a free-water surface constructed wetland for the treatment of a metallurgical effluent for 5 years. Removal efficiencies were satisfactory. To increase metal tolerance, its transport from belowground to aboveground tissues is reduced, being metal concentrations in the roots and rhizomes significantly higher than in the aerial and submerged parts of leaves. Regarding belowground tissues, metals were retained in the roots, while P was mainly accumulated in rhizomes. Bioaccumulation factors (BAFs) of Cr and Ni showed values near 1, and BAF of Zn and P were above 1 in several samplings, indicating bioaccumulation in the roots. Translocation factors (TFs) of Cr, Ni, and Zn were below 1, showing a scarce translocation from the roots to the aerial parts of the leaves, while the TF of P were above 1 in many samplings, indicating that this element is necessary for plant metabolism. The study of plant tissues where contaminants are accumulated allows gaining insight into the constructed wetland operation. The high translocation of P in T. domingensis makes this species suitable for its phytoextraction, while the low metal translocation makes T. domingensis suitable for phytostabilization.

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Resumen El cultivo del café, en la economía mexicana y en la región del Soconusco en Chiapas, aporta importantes divisas; sin embargo es susceptible a plagas y enfermedades, por lo que se requiere reforzar su producción a través de un manejo más sustentable. Este estudio analizó la abundancia, riqueza y composición de hongos micorrizógenos arbusculares (HMA) nativos que pudieran emplearse en un futuro como biofertilizantes en el cultivo del café. En 21 muestras de suelo recolectadas en noviembre 2015 de siete sitios en la región del Soconusco, Chiapas, México, cultivados con café "robusta" (Coffea canephora), se cuantificó la abundancia de esporas, la riqueza y composición de morfoespecies de HMA y se exploró su relación con las propiedades del suelo. Se obtuvo un total de 20 morfoespecies y cinco nuevos registros de HMA para Chiapas, las morfoespecies más frecuentes pertenecen a los géneros Acaulospora y Glomus. Los sitios Toluca y Victoria tuvieron mayor riqueza de especies (17 spp. c/u) que San Agustín, 20 de noviembre y San Luis Nexapa (4 - 7 spp. c/u); mientras que Providencia y Platanar registraron una riqueza intermedia y los mayores valores de abundancia de esporas. Los sitios Victoria y Toluca presentaron un 97 % de disimilitud en la composición de especies de HMA con respecto a los demás sitios; la cual fue explicada por la baja concentración de PO4 -3en el suelo de Victoria y Toluca. La disponibilidad de P, ligada a la acidez del suelo, fueron los factores que podrían estar regulando las comunidades de HMA en el suelo de la rizosfera de los cafetos en la región del Soconusco. Se propone que podrían haber consorcios de HMA específicos para los niveles de P y acidez presentes en diferentes sitios con cafetos, o bien consorcios de especies de Acaulospora y Glomusacordes con las condiciones ambientales en las que se desarrolla el café, cuya compatibilidad y funcionalidad debe examinarse antes de emplearlos como biofertilizantes nativos en los cafetos de esta región tropical de México.

Abstract In the Mexican economy, and especially in the Soconusco region of Chiapas, coffee is economically important, and sustainable management most cover pests and diseases. In this study, we searched for native arbuscular mycorrhizal fungi (AMF) that could be used as biofertilizers in coffee cultivation. We collected 21 soil samples from seven coffee plantations (Coffea canephora) in November 2015. We used wet sieving and decanting to quantify abundance, richness and composition of morphospecies, as well as their relationships with soil properties. A total of 20 morphospecies and five new records of AMF were obtained, and the most frequent genera were Acaulospora and Glomus. The Toluca and Victoria sites had more morphospecies richness (17 spp. each) than San Agustín, November 20 and San Luis Nexapa (4-7 spp. each). Providencia and Platanar were intermediate but had the highest spore abundance. The dissimilarity of Victoria and Toluca may reflect a low concentration of PO4 -3in the soil. P availability, linked to soil acidity, sems to be regulating these mycorrhizae communities at Soconusco. AMF consortia specific for soil P-levels and acidity, i.e. Acaulospora and Glomusconsortia, may occur and be common in the environmental conditions of Mexican coffee plantations, Strains should be tested for compatibility and functionality before using them as native biofertilizers. Rev. Biol. Trop. 66(1): 91-105. Epub 2018 March 01.

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Ornithine lipids (OLs) are phosphorus-free lipids found in many bacteria grown under phosphate deprivation, a condition that activates the PhoBR system and leads to phosphate uptake and metabolism. Two OL synthesis pathways have already been described. One depends on OlsB and OlsA acyltransferases to add, respectively, the first and second acyl chains to an ornithine molecule. The other pathway is carried out by OlsF, a bifunctional enzyme responsible for both acylation steps. Although Vibrio cholerae lacks olsBA genes, an olsF homologue (vc0489) was identified in its genome. In this work we demonstrated that V. cholerae produces OLs and expresses vc0489 in response to phosphate depletion, in a PhoBR-dependent manner. In Escherichia coli, under similar condition, vc0489 expression leads to OL accumulation. These results indicate a strong connection between OL synthesis and VC0489 from V. cholerae and, for the first time, a direct regulation of an olsF homologue by the PhoBR system.

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Abstract This study was aimed to investigate the effect of bio-organic phosphate either alone or in combination with phosphorus solubilizing bacteria strain (Bacillus MWT-14) on the growth and productivity of two wheat cultivars (Galaxy-2013 and Punjab-2011) along with recommended (150100 NP kg ha1) and half dose (7550 NP kg ha1) of fertilizers. The combined application of bio-organic phosphate and the phosphorous solubilizing bacteria strain at either fertilizer level significantly improved the growth, yield parameters and productivity of both wheat cultivars compared to non-inoculated control treatments. The cultivar Punjab-2011 produced the higher chlorophyll contents, crop growth rate, and the straw yield at half dose of NP fertilizer; while Galaxy-2013, with the combined application of bio-organic phosphate and phosphorous solubilizing bacteria under recommended NP fertilizer dose. Combined over both NP fertilizer levels, the combined use of bio-organic phosphate and phosphorous solubilizing bacteria enhanced the grain yield of cultivar Galaxy-2013 by 54.3% and that of cultivar Punjab-2011 by 83.3%. The combined application of bio-organic phosphate and phosphorous solubilizing bacteria also increased the population of phosphorous solubilizing bacteria, the soil organic matter and phosphorous contents in the soil. In conclusion, the combined application of bio-organic phosphate and phosphorous solubilizing bacteria offers an eco-friendly option to harvest the better wheat yield with low fertilizer input under arid climate.