Changes In Nutrient Concentrations Research Articles

Seasonal changes of mineral nutrients absorption and allocation in fruit of Zanthoxylum bungeanum ‘Hanyuan’ during the development

Learn about the dynamic changes of mineral nutrients in fruit is important to make effective fertilization measures during the fruit development. The content and accumulation of mineral nutrients (included N, P, K, Ca, Mg, Fe, Mn, Cu and Zn) in fruit (included pericarp, seed and whole fruit) of Zanthoxylum bungeanum 'Hanyuan' were measured during the development to explore nutrient requirements and allocation. The changes of nutrient contents and accumulation in fruit of Z. bungeanum ‘Hanyuan’ showed a similar trend. A temporary increase was observed in the content of N, P, Mg, Mn and Cu after blooming (AF). Subsequently, all nutrient contents declined rapidly during the fruit enlargement stage and a slight decrease during the seed formation stage, while the nutrient contents remained relatively stable in the other stages. The nutrient accumulation increased the most rapidly during the fruit enlargement and seed development stages, and there was a highly significant linear correlation between the fruit nutrient accumulation and dry weight (P < 0.05). Except for N and Mn, the content and accumulation of other nutrients were higher in the seed than that in the pericarp. Furthermore, the nutrient accumulation in fruit at maturity (115 d AF) ranked as Ca > K > N > Mg > P > Fe > Mn > Zn > Cu. Both the fruit enlargement (15–39 d AF) and seed development (57–86 d AF) stages are crucial periods for nutrient requirements. The nutrient absorption by the seed was increased, and nutrient accumulation in the pericarp tended to slow down or remained relatively stable during the seed development stage.

Enabling Smart Agriculture through Sensor-Integrated Microfluidic Chip to Monitor Nutrient Uptake in Plants

The soil microenvironment greatly influences a plant’s ability to absorb nutrients and germinate. Sensing these changes in soil medium is critical to understand plant nutrient requirements. Soil being dynamic represents changes in nutrient content, element mobility, texture, water-holding capacity, and microbiota which affects the nutrient levels. These minor changes affect the plant in early growth and development and studying these changes has always been challenging. Microfluidics provides a platform to study nutrient availability and exchange in small volumes of liquid or media resembling plant microenvironments. Here, we have developed a novel microfluidic chip-embedded molecular imprinted sensor for sensing nitrate and phosphate in the media. For data acquisition and recording we have implemented a potentiostat controlled via a microcontroller allowing data storage and transfer via a long-range radio module (LoRA). The microfluidic device’s functionality was validated by germination of the legume crimson red and recoding the nitrate and phosphate levels in media for 7 d. The MIP-based sensor measures nitrate and phosphate, in the range from 1 to 1000 mM. The accuracy of detection for nitrate and phosphate showed 99% and 95% respectively. The chip coupled with MIP based sensor for nutrient analysis serves as a platform technology for studying nitrate and phosphate nutrient exchange and interaction. This chip in the future can be implemented to study plant deficiencies, drought resistance, and plant immunity.

Seasonal variation of gross ecosystem productivity of periphyton in three post-mining lakes in the Czech Republic, Europe

We investigated the seasonal variation of gross ecosystem productivity (GEP) of periphyton biomass in three post-mining lakes in the Czech Republic. These lakes were established as part of recultivation efforts after coal mining activities and resulted in a unique series of anthropogenic oligotrophic lakes of gradual successional age. Periphyton is ubiquitous in aquatic habitats and performs numerous environmental functions such as nutrient cycling and self-purifying of aquatic ecosystems. Well-developed periphyton mat can be formed within a few weeks, so it can quickly become the dominant of littoral zone of newly established lakes. In studied post-mining lakes, the highly developed periphytic community covers the littoral zone of each lake to the depth of 2m (Bešta et al. 2022, Konopáčová et al. 2023) Fig. 1. We aimed to shed some new light on the processes controlling the dynamics of primary productivity in oligotrophic lakes. The accurate estimation of primary productivity is crucial for understanding the functioning of aquatic ecosystems, as primary productivity serves as the primary source of autochthonous carbon in these systems. In addition to phytoplankton, periphyton can significantly contribute to primary productivity in littoral zones, known for their high productivity and biodiversity. Conducting in situ measurements provides the most accurate means of inferring the metabolic activity of primary producers in littoral zones. We conducted detailed seasonal in-situ periphyton gross primary production (GPP) measurements in three post-mining lakes with different successional ages (Čapková et al. 2022). GPP and NPP of periphytic biomass were determined using direct in-situ measurement of O2 fluxes. O2 production and consumption were measured over 5 hours of in-situ light and dark gas-tight glass bottle incubation. Bottles were filled with the lake water from the corresponding depth, and a similar amount of periphytic biomass was enclosed Fig. 2. We used the Fibox3 fibre-optic oxygen meter coupled with a PSt3 oxygen sensor (PreSens, Regensburg, DE) to measure changes in O2 concentration. The O2 fluxes were normalized to periphytic biomass in each bottle (measured as total organic carbon). Data were corrected for O2 concentration changes in dark and light gas-tight bottles containing lake water without periphytic communities. This setup enabled us to monitor online oxygen flux, therefore, insights into metabolic activities. The primary productivity was measured in real-time, allowing us to capture the quantitative effect of various environmental drivers on periphyton productivity, i.e. phosphorus concentration and light intensity, as they are known to play significant roles in primary productivity. We showed that the primary production of periphyton mats exhibited seasonal variations, with higher productivity observed in spring compared to other seasons. This observation could be attributed to the occurrence of winter/spring upwelling events and vertical mixing, which resupply nutrients from the deeper strata. Furthermore, the physiological activity of periphyton was strongly influenced by the seasonal changes in light intensity, temperature, and nutrient concentration. We provided the first insight into the seasonal variation of primary productivity of the periphyton assemblage dominating the littoral zone of newly established post-mining lakes. We stress the importance of periphyton in aquatic ecosystems, particularly in anthropogenic oligotrophic lakes.

Changes in Plant Nutrient Concentration of Olive (Olea europaea L.) Leaves after Different Rates of Humic Acid Application

This research was a one-year study to investigate how increasing rates of humic acid affect the nutrient elements [Nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu)] of olive trees (Olea europaea) of 14 years old found in a private cultivation land located in Bozköy of Geyikli, Çanakkale (Latitude 35 S 431667, Longitude 4409876) in 2018. The humic acid used was a suspension of 15% humic and fulvic acid, which was a commercial product (Blackjak SC, pH 4-6). Different concentrations of humic acid [0 (control), 50, 100, 200, 400 mL tree-1] were applied directly to soil of 20-30 cm depth under canopy projection of trees after dissolving in 10 L of water in April. A randomized block design with four replicates and five doses was adopted on 20 trees. 200 leaf samples were taken in December from annual shoot tips as reciprocal leaf couples and nutrient element analyses were carried out. The macronutrient elements N and P significantly increased upon all humic acid applications. However, the changes in the elements K, Ca, Mg, Fe, Zn, and Mn were insignificant in all applications. Humic acid at all concentrations decreased copper in leaves. As a result, addition to routine farmer fertilization, humic acid application at the rate of 50 ml tree-1 was determined to be the sufficient dose for olive trees. Moreover, this mentioned dose is considered to be the most economical dose besides being the most suitable one.

Changes in Nutrient Concentrations and Limitations of Poyang Lake Associated with Socioeconomic Development in the Watershed from 1978 to 2021

Socioeconomic development often leads to environmental pollution and degradation initially while, beyond a certain point, there is the potential for improvements in environmental quality. In this study, we conducted a comprehensive review of published literature and national data to investigate changes in nutrient concentrations and limitations in Poyang Lake from 1978 to 2021. Our objective was to examine the relationships between these changes and the process of socioeconomic development in the watershed. The findings revealed a rapid socioeconomic development of the Poyang Lake Watershed, showing significant changes in various indexes. For example, population, Gross Domestic Product (GDP), urbanization, grain and meat productions, sewage amount and treatment rate, and forest coverage in the watershed showed increasing trends with different fitting curves, each following distinct fitting curves such as exponential, binary, and linear models. Concurrently, the concentrations of total nitrogen (TN) and total phosphorus (TP) in Poyang Lake exhibited a linear increase over the years, surpassing eutrophication thresholds since the early 1980s. However, TN and TP have shown a decreasing trend in recent years. Notably, the lake displayed co-limitation by N and P, with TN primarily driving the N:P ratio. TN and TP showed a significant “∩” shape with the increase in GDP and urbanization, while they increased with the population. TN:TP showed an increasing pattern with GDP and urbanization but a “U” shape with the population. This research contributes significant insights into the long-term changes in nutrient concentrations, shifts in nutrient limitations, and their associations with socioeconomic development. The findings highlight the need for a balanced and strategic approach to appropriately manage both nutrients for effective eutrophication mitigation.

Optimizing Straw-Rotting Cultivation for Sustainable Edible Mushroom Production: Composting Spent Mushroom Substrate with Straw Additions.

In recent years, the optimization of straw-rotting formulations for cultivating edible mushrooms and the management of the resulting spent mushroom substrate have emerged as new challenges. This study aimed to investigate the composting of spent mushroom substrate produced from mushroom cultivation with various straw additions, under conditions where chicken manure was also used. Parameters measured during the composting process included temperature, pH, electrical conductivity (EC), germination index (GI), moisture, and total nitrogen content. Additionally, changes in nutrient content within the compost piles before and after composting were determined, and the variations in bacterial and fungal communities across different treatments before and after composting were analyzed using 16S rRNA and ITS sequencing. The results indicated that the spent mushroom substrate produced by adding 20% straw during mushroom cultivation was more suitable for composting treatment. The findings suggest that incorporating an appropriate amount of straw in mushroom cultivation can facilitate subsequent composting of spent mushroom substrate, providing an effective strategy for both environmental protection and cost reduction.

MurKy waters: Modeling the succession from r to K strategists (diatoms to dinoflagellates) following a nutrient release from a mining facility in Florida

AbstractThe impacts of pulsed nutrient injections or extreme runoff events on marine ecosystems are far less studied than those associated with long‐term eutrophication, particularly in regard to mechanisms regulating the response of plankton community structure. Over 800 million liters of nutrient‐rich water from a fertilizer mine were discharged over a 2‐week period into Tampa Bay, Florida, in 2021, providing a unique opportunity to document the plankton response. A 3D‐coupled hydrodynamic biogeochemical model was developed to investigate this response and to understand the observed succession of a large, short diatom bloom followed by a secondary Karenia brevis bloom that lasted through the summer. The model reproduced the observed changes in nutrient concentration, total chlorophyll a, and diatom and K. brevis biomass in Tampa Bay. With a faster growth rate and spring temperature close to the optimal window of growth, diatoms had an initial competitive advantage, with 2/3 of the nutrient uptake due to ammonium and 1/3 due to nitrate. However, exhaustion of external nutrients led to the rapid decline of the diatom bloom, and the associated particular organic nitrogen sank onto the bay sediment. Enhanced sediment release of ammonium during the weeks following, and summer remineralization of dissolved organic nitrogen provided sufficient regenerated nitrogen to support slow‐growing K. brevis that could capitalize on low nutrient conditions. Modeling analysis largely confirmed Margalef's conceptual model of r to K‐selected species succession and provided additional insights into nutrient cycling supporting the initial diatom bloom and the subsequent bloom of a slow‐growing harmful algal species.

Siting and evaluation of offshore suspended mussel farms through nutritional restriction approach

An individual-based model based on mussel feeding on algae was developed for the first time, and the model was introduced to a three-dimensional water quality model based on nitrogen, phosphorus, phytoplankton cycling and dissolved oxygen balance, describing the ecological influence of mussel feeding. The drag of aquaculture facilities on suspended farms was introduced to a three-dimensional hydrodynamic model. The water quality model was coupled with the three-dimensional hydrodynamic model to simulate the hydrodynamic environment field of a large offshore suspended mussel farm in Gouqi Island throughout a year. The simulation results agree well with observations. Based on the nutritional restriction approach, the cause of mussel mortality in Gouqi Island is insufficient algal concentration and insufficient filtration rate. Accordingly, an optimized site selection of the suspended mussel farms was proposed, and its feasibility was validated in hydrology and water quality by using the model. Furthermore, hydrodynamic and ecological effects of aquaculture facilities and site selection were quantified. Aquaculture facilities in Gouqi Island reduces surface current speed by 86% and increases half-time of water exchange by 64%. P is the limiting nutrient in the suspended mussel farms of Gouqi Island. The siting of offshore suspended mussel farms only changes the local distribution of nutrients, causing minimal changes in nutrient concentrations and having limited ecological influence.

Effects of phosphorus species and zinc stress on growth and physiology of the marine diatom Thalassiosira weissflogii

Human activities, including industrial and agricultural production, as well as domestic sewage discharge, have led to heavy metal pollution and eutrophication in coastal waters. This has caused a deficiency of dissolved inorganic phosphorus (DIP), but an excess dissolved organic phosphorus (DOP) and high concentrations of zinc. However, the impact of high zinc stress and different phosphorus species on primary producers remains unclear. This study examined the impact of different phosphorus species (DIP and DOP) and high zinc stress (1.74 mg L−1) on the growth and physiology of the marine diatom Thalassiosira weissflogii. The results showed that compared to the low zinc treatment (5 μg L−1), high zinc stress significantly decreased the net growth of T. weissflogii, but the decline was weaker in the DOP group than in the DIP group. Based on changes in photosynthetic parameters and nutrient concentrations, the study suggests that the growth inhibition of T. weissflogii under high zinc stress was likely due to an increase in cell death caused by zinc toxicity, rather than a decrease in cell growth caused by photosynthesis damage. Nonetheless, T. weissflogii was able to reduce zinc toxicity by antioxidant reactions through enhancing activities of superoxide dismutase and catalase and by cationic complexation through enhancing extracellular polymeric substances, particularly when DOP served as the phosphorus source. Furthermore, DOP had a unique detoxification mechanism by producing marine humic acid, which is conducive to complexing metal cations. These results provide valuable insights into the response of phytoplankton to environmental changes in coastal oceans, particularly the effects of high zinc stress and different phosphorus species on primary producers.

Nonpoint source pollution measures in the Clean Water Act have no detectable impact on decadal trends in nutrient concentrations in U.S. inland waters.

The Clean Water Act (CWA) of 1972 regulates water quality in U.S. inland waters under a system of cooperative federalism in which states are delegated implementation and enforcement authority of CWA provisions by the U.S. Environmental Protection Agency. We leveraged heterogeneity in state implementation of the CWA to evaluate the efficacy of its nonpoint source provisions in reducing nutrient pollution, the leading cause of water quality impairment in U.S. inland waters. We used national survey data to estimate changes in nutrient concentrations over a decade and evaluated the effect of state-level policy implementation. We found no evidence to support an effect of (i) grant spending on nonpoint source pollution remediation, (ii) nutrient criteria development, or (iii) water quality monitoring intensity on 10-year trends in nutrient concentrations. These results suggest that the current federal policy paradigm for improving water quality is not creating desired outcomes.

The genome of okra (Abelmoschus esculentus) provides insights into its genome evolution and high nutrient content.

Okra (Abelmoschus esculentus) is an important vegetable crop with high nutritional value. However, the mechanism underlying its high nutrient content remains poorly understood. Here, we present a chromosome-scale genome of okra with a size of 1.19Gb. Comparative genomics analysis revealed the phylogenetic status of A. esculentus, as well as whole-genome duplication (WGD) events that have occurred widely across the Malvaceae species. We found that okra has experienced three additional WGDs compared with the diploid cotton Gossypium raimondii, resulting in a large chromosome number (2n = 130). After three WGDs, okra has undergone extensive genomic deletions and retained substantial numbers of genes related to secondary metabolite biosynthesis and environmental adaptation, resulting in significant differences between okra and G. raimondii in the gene families related to cellulose synthesis. Combining transcriptomic and metabolomic analysis, we revealed the relationship between gene expression and metabolite content change across different okra developmental stages. Furthermore, the sinapic acid/S-lignin biosynthesis-related gene families have experienced remarkable expansion in okra, and the expression of key enzymes involved in the sinapic acid/S-lignin biosynthesis pathway vary greatly across developmental periods, which partially explains the differences in metabolite content across the different stages. Our study gains insights into the comprehensive evolutionary history of Malvaceae species and the genetic basis that underlies the nutrient content changes in okra, which will facilitate the functional study and genetic improvement of okra varieties.

Vegetable substituted tuna nuggets and changes in nutrient content during frozen storage

Malnutrition in children will affect their growth, causing a decrease in study skills and immunity. Considering the issues, overcoming the nutritional issues of babies and toddlers by giving food supplements is mandatory. Innovations in making food supplements basically from fish aim to increase the number of nutritions such as protein, fiber, vitamins, minerals, and antioxidants which contribute to the development of body organ function. This research is aimed to know the changes in iron, beta carotene, and zinc during storage. The research design is experimental. The first stage is making tuna nuggets which are substituted with pumpkin, broccoli, and red beans. Furthermore, the analysis of nutrients before and after storage in the freezer for 3 months. There was a decrease in beta carotene levels in pumpkin tuna nuggets, broccoli tuna, and red bean tuna, 34.5%, 14.2%, and 9.6%, respectively. There was an increase in the iron content of pumpkin tuna nuggets, broccoli tuna, and red bean tuna as much as 65.2%, 7.1%, and 30%, respectively. There was a decrease in zinc levels in pumpkin tuna and broccoli tuna nuggets as much as 23.6% and 78.8%, respectively. There was an increase in zinc levels in red bean tuna nuggets as much as 46.3%. Storage of nuggets in frozen conditions in the freezer for 3 months causes changes in beta carotene, iron, and zinc levels.

Rhizosphere microbial community composition shifts diurnally and in response to natural variation in host clock phenotype.

Plant-associated microbial assemblages are known to shift at time scales aligned with plant phenology, as influenced by the changes in plant-derived nutrient concentrations and abiotic conditions observed over a growing season. But these same factors can change dramatically in a sub-24-hour period, and it is poorly understood how such diel cycling may influence plant-associated microbiomes. Plants respond to the change from day to night via mechanisms collectively referred to as the internal "clock," and clock phenotypes are associated with shifts in rhizosphere exudates and other changes that we hypothesize could affect rhizosphere microbes. The mustard Boechera stricta has wild populations that contain multiple clock phenotypes of either a 21- or a 24-hour cycle. We grew plants of both phenotypes (two genotypes per phenotype) in incubators that simulated natural diel cycling or that maintained constant light and temperature. Under both cycling and constant conditions, the extracted DNA concentration and the composition of rhizosphere microbial assemblages differed between time points, with daytime DNA concentrations often triple what were observed at night and microbial community composition differing by, for instance, up to 17%. While we found that plants of different genotypes were associated with variation in rhizosphere assemblages, we did not see an effect on soil conditioned by a particular host plant circadian phenotype on subsequent generations of plants. Our results suggest that rhizosphere microbiomes are dynamic at sub-24-hour periods, and those dynamics are shaped by diel cycling in host plant phenotype. IMPORTANCE We find that the rhizosphere microbiome shifts in composition and extractable DNA concentration in sub-24-hour periods as influenced by the plant host's internal clock. These results suggest that host plant clock phenotypes could be an important determinant of variation in rhizosphere microbiomes.

Acidification and hypoxia drive physiological trade-offs in oysters and partial loss of nutrient cycling capacity in oyster holobiont

IntroductionReef building oysters provide vast ecological benefits and ecosystem services. A large part of their role in driving ecological processes is mediated by the microbial communities that are associated with the oysters; together forming the oyster holobiont. While changing environmental conditions are known to alter the physiological performance of oysters, it is unclear how multiple stressors may alter the ability of the oyster holobiont to maintain its functional role.MethodsHere, we exposed oysters to acidification and hypoxia to examine their physiological responses (molecular defense and immune response), changes in community structure of their associated microbial community, and changes in water nutrient concentrations to evaluate how acidification and hypoxia will alter the oyster holobiont’s ecological role.ResultsWe found clear physiological stress in oysters exposed to acidification, hypoxia, and their combination but low mortality. However, there were different physiological trade-offs in oysters exposed to acidification or hypoxia, and the combination of stressors incited greater physiological costs (i.e., &amp;gt;600% increase in protein damage and drastic decrease in haemocyte counts). The microbial communities differed depending on the environment, with microbial community structure partly readjusted based on the environmental conditions. Microbes also seemed to have lost some capacity in nutrient cycling under hypoxia and multi-stressor conditions (~50% less nitrification) but not acidification.DiscussionWe show that the microbiota associated to the oyster can be enriched differently under climate change depending on the type of environmental change that the oyster holobiont is exposed to. In addition, it may be the primary impacts to oyster physiology which then drives changes to the associated microbial community. Therefore, we suggest the oyster holobiont may lose some of its nutrient cycling properties under hypoxia and multi-stressor conditions although the oysters can regulate their physiological processes to maintain homeostasis on the short-term.

Atlantic circulation changes across a stadial–interstadial transition

Abstract. We combine consistently dated benthic carbon isotopic records distributed over the entire Atlantic Ocean with numerical simulations performed by a glacial configuration of the Norwegian Earth System Model with active ocean biogeochemistry in order to interpret the observed Cibicides δ13C changes at the stadial–interstadial transition corresponding to the end of Heinrich Stadial 4 (HS4) in terms of ocean circulation and remineralization changes. We show that the marked increase in Cibicides δ13C observed at the end of HS4 between ∼2000 and 4200 m in the Atlantic can be explained by changes in nutrient concentrations as simulated by the model in response to the halting of freshwater input in the high-latitude glacial North Atlantic. Our model results show that this Cibicides δ13C signal is associated with changes in the ratio of southern-sourced (SSW) versus northern-sourced (NSW) water masses at the core sites, whereby SSW is replaced by NSW as a consequence of the resumption of deep-water formation in the northern North Atlantic and Nordic Seas after the freshwater input is halted. Our results further suggest that the contribution of ocean circulation changes to this signal increases from ∼40 % at 2000 m to ∼80 % at 4000 m. Below ∼4200 m, the model shows little ocean circulation change but an increase in remineralization across the transition marking the end of HS4. The simulated lower remineralization during stadials compared to during interstadials is particularly pronounced in deep subantarctic sites, in agreement with the decrease in the export production of carbon to the deep Southern Ocean during stadials found in previous studies.

Analysis of phytoplankton abundance in kassikebo waters, pangkep regency, south sulawesi, indonesia

Changes in nutrient concentrations can be caused by anthropogenic activities in coastal and marine waters. This affects the abundance of phytoplankton. The waters experiencing it are the waters of Kassikebo Pangkep, South Sulawesi, Indonesia. For this reason, research has been carried out to analyze the abundance and structure of phytoplankton communities in these waters, from January to July 2022. To identify phytoplankton, 100 L of seawater samples were filtered, which were taken at each station. The results of that water filter, identified in the laboratory. The results showed that the classes of phytoplankton found were Bacillariophyceae and Cyanophyceae. Species found such as Skeletonema and Detonula. The results of One-way ANOVA showed that phytoplankton abundance was not significantly different between observation stations (p&gt;0.05). Changes in phytoplankton abundance are caused by pH.

Interactions between rootstocks and compost influence the active rhizosphere bacterial communities in citrus

BackgroundWhile the rootstock genotype (belowground part of a plant) can impact rhizosphere microbial communities, few studies have examined the relationships between rootstock genotype-based recruitment of active rhizosphere bacterial communities and the availability of root nutrients for plant uptake. Rootstocks are developed to provide resistance to disease or tolerance of abiotic stresses, and compost application is a common practice to also control biotic and abiotic stresses in crops. In this field study, we examined: (i) the effect of four citrus rootstocks and/or compost application on the abundance, diversity, composition, and predicted functionality of active rhizosphere bacterial communities, and (ii) the relationships between active rhizosphere bacterial communities and root nutrient concentrations, with identification of bacterial taxa significantly correlated with changes in root nutrients in the rhizosphere.ResultsThe rootstock genotype determined differences in the diversity of active rhizosphere bacterial communities and also impacted how compost altered the abundance, diversity, composition, and predicted functions of these active communities. Variations in the active bacterial rhizobiome were strongly linked to root nutrient cycling, and these interactions were root-nutrient- and rootstock-specific. Direct positive relationships between enriched taxa in treated soils and specific root nutrients were detected, and potentially important taxa for root nutrient uptake were identified. Significant differences in specific predicted functions were related to soil nutrient cycling (carbon, nitrogen, and tryptophan metabolisms) in the active bacterial rhizobiome among rootstocks, particularly in soils treated with compost.ConclusionsThis study illustrates that interactions between citrus rootstocks and compost can influence active rhizosphere bacterial communities, which impact root nutrient concentrations. In particular, the response of the rhizobiome bacterial abundance, diversity, and community composition to compost was determined by the rootstock. Specific bacterial taxa therefore appear to be driving changes in root nutrient concentrations in the active rhizobiome of different citrus rootstocks. Several potential functions of active bacterial rhizobiomes recruited by different citrus rootstocks did not appear to be redundant but rather rootstock-specific. Together, these findings have important agronomic implications as they indicate the potential for agricultural production systems to maximize benefits from rhizobiomes through the choice of selected rootstocks and the application of compost.6QRnEBPSbTfGkWz6eGytjbVideo

Metabolic Complications Associated With Total Parenteral Nutrition

Total parenteral nutrition (TPN) is a very important means of providing nutrients to patients who have no access to receiving nutrients by enteral route. It consists of all the essential components like lipids, protein, dextrose, electrolytes, vitamins, minerals and trace elements. The concentration of all these components can be adjusted according to the requirement of the patients. They are also available as fixed solutions. Administration of TPN requires careful monitoring as small change in concentration of nutrients in the solution may cause serious, life-threatening complications. Metabolic complications like electrolyte abnormalities, refeeding syndrome, hyperglycemia, hypertriglyceridemia and many hepatobiliary dysfunctions like steatosis, cholestasis, hepatic dysfunction and gallbladder dysfunction are all associated with the use of total parenteral nutrition.&#x0D;

Effects of sediment resuspension and changes in water nutrient concentrations on the remobilization of lead from contaminated sediments in Klity Creek, Thailand

As Pb-containing sediments in Klity Creek have had negative impacts on the area for more than 20 years, the Supreme Court ordered the Pollution Control Department (PCD) of Thailand to remediate the site. In response to the court order, the PCD decided to reduce the contamination level by dredging the sediments of the creek. Therefore, this study is the first investigation to be conducted on the coupled effects of sediment resuspension caused by dredging and changes in water nutrient concentrations upon the remobilization of Pb from sediments into the water column. The Pb concentrations and speciation in both the water and sediments collected from upstream and downstream regions of the contaminated area were determined. The results showed that the total Pb concentrations in the water taken from all sampling sites in both the dry and wet seasons were lower than the national standard (50 μg/L), and a very low mobility index was found for Pb. The highest total Pb concentration in the sediments (6930 mg/kg) from the downstream site was 23.7- to 30.4-fold greater than those of the sediments collected from the upstream site. The predominant Pb species (organic and residual Pb fractions) in the sediments collected during the dry season were identified. However, carbonate- and Fe–Mn oxide-bound Pb fractions were mainly found in the sediments collected in the wet season. The diffusive gradients in thin films (DGT)-labile Pb concentrations, which reached 2.1 mg/L, indicated potential toxicity to aquatic organisms. A total of nine resuspension scenarios generalizing all changes in water nutrient concentrations in addition to sediment resuspension due to dredging were constructed. The results confirmed that sediment resuspension alone could remobilize Pb from the sediments into the water at levels from 0.06 to 16.9 μg/L. Sediment resuspension in water contaminated with 1 mg/L phosphate (PO43−) led to the dissolution of 28.4–73.0 μg/L Pb in the water column. Nitrate (NO3−) did not significantly remobilize Pb from the sediments into the water. The high ionic strength and activity coefficient of PO43− in the water were expected to cause the retention of dissolved Pb in the water and enhance the remobilization of Pb from the sediments due to the association of Pb with PO43− in the water.

Nitrogen forms and concentration influence the impact of titanium dioxide nanoparticles on the biomass and antioxidant enzyme activities of Microcystis aeruginosa

Nanoparticles (NPs) are becoming more widely produced, used, and released into the aquatic environment. In aquatic ecosystems, these NPs affect different populations of photosynthesizing organisms, such as cyanobacteria. This study aimed to evaluate the effects of titanium dioxide (TiO2) NPs (48mgl-1) combined with low (0.04mM) and high (9mM) concentrations of urea and nitrate on Microcystis aeruginosa. Microcystins (MCs) production and release were monitored in the cyanobacterium. The results showed that high urea concentration (9mM) combined with TiO2 NPs inhibited growth, pigment, and malondialdehyde (MDA) content by 82%, 63%, and 47%, respectively. The treatment also increased the reactive oxygen species (ROS) and glutathione S-transferase (GST) activity by 40.7% and 67.7%, respectively. Similarly, low nitrate (0.04mM) combined with TiO2 NPs inhibited growth by 40.3% and GST activity by 36.3% but stimulated pigment production and ROS concentration in M. aeruginosa. These responses suggest that high urea combined with TiO2.NPs and high nitrate combined with TiO2 NPs induced oxidative stress in cyanobacteria. The peroxidase (POD) activity of M. aeruginosa decreased by 17.7% with increasing urea concentrations. Our findings suggest that TiO2 NPs combined with changing nutrient (urea and nitrate) concentrations may adversely affect cyanobacterial development and antioxidant defense enzymes.