High Levels Of Manganese Research Articles

Determining the Relationship Between Zinc Status and Blood Manganese Levels on Enzymatic Markers of Tissue Damage: An Epidemiological Study Using NHANES 2013-2016 Data

Manganese is an essential trace element required for various physiological processes. However, excessive exposure to this metal can lead to health issues. This study aims to evaluate whether adequate zinc intake can influence the relationship between blood manganese levels and markers indicating damage to the liver and other organs in populations using epidemiological data. We conducted a comprehensive analysis utilizing 2013–2016 data from the National Health and Nutrition Examination Survey (NHANES). The findings indicated that blood manganese exhibits a significant positive association with the serum levels of enzymatic markers of liver damage alkaline phosphatase and aspartate aminotransferase. However, when investigating the interaction of blood manganese and zinc intake at the second quartile, a significant negative association was found with alkaline phosphatase in three different linear regression models. A similar association was found between the fourth quartile of zinc intake and lactate dehydrogenase activity in all three models of the study. The findings suggest that unhealthy high levels of manganese in population could be widespread and may lead to tissue injury and disease. Nevertheless, having an adequate zinc intake could help mitigate manganese toxicity.

Assessment of Essential Trace Elements Cu, Zn, Mn, and Ni in Mediterranean Mussels (Mytilus galloprovincialis) from the Algerian Coast.

The aim of this study was to determine the levels of essential trace elements copper, zinc, manganese, and nickel in two size groups of mussels, Mytilus galloprovincialis, sampled from three sites along the Algerian coast with different levels of pollution. The results of this work are very interesting for determining the effect of mussel size on the variation of contaminant levels in environmental monitoring studies. Thirty individuals from 2 size groups, less than 4-cm and more than 4-cm shell length, were collected over 4 seasons at each site studied. The samples were dissected, and copper, zinc, manganese, and nickel were measured in the whole soft tissues by inductively coupled plasma mass spectrometry (ICP-MS). The maximum concentrations of copper, zinc, manganese, and nickel expressed in mg/kg dry weight at the three sites were 54.01, 146.25, 20.69, and 8.85, respectively. A clear distribution pattern of the studied elements was observed in the two size classes. In fact, significantly higher concentrations (P < 0.05) were found in individuals with a shell length of less than 4 cm. Significantly, higher concentrations (P < 0.05) were found in individuals with a shell length of less than 4 cm due to their high filtration and low excretion activities compared to long individuals. In addition, metal pollution index (MPI) values were higher in small bivalve individuals. The trace element contents found in the mussel samples of the present study showed large spatial and temporal variations among the different sites studied, highlighting the typical exposure of marine sites to different marine pollutants. Notably, elevated concentrations of copper were observed in the port of Zemmouri, likely due to port activities. Conversely, the highest levels of manganese and nickel were recorded at Boudouaou El Bahri, potentially attributable to the use of fertilisers by agricultural activities. Some shellfish samples had exceeded the permissible concentration levels of copper and manganese, thereby posing a danger to bivalve consumers.

Proteomic Insights into Trichome Responses to Elevated Elemental Stress in Cation Exchanger (CAX) Mutants.

Research on elemental distribution in plants is crucial for understanding nutrient uptake, environmental adaptation, and optimizing agricultural practices for sustainable food production. Plant trichomes, with their self-contained structures and easy accessibility, offer a robust model system for investigating elemental repartitioning. Transport proteins, such as the four functional cation exchangers (CAXs) in Arabidopsis, are low-affinity, high-capacity transporters primarily located on the vacuole. Mutants in these transporters have been partially characterized, with one of the phenotypes of the CAX1 mutant being altered tolerance to low-oxygen conditions. A simple visual screen demonstrated trichome density and morphology in cax1 and quadruple CAX (cax1-4: qKO) mutants remained unaltered. Here we used SXRF (Synchrotron X-Ray Fluorescence) to show that trichomes in CAX-deficient lines accumulated high levels of chlorine, potassium, calcium, and manganese. Proteomic analysis on isolated Arabidopsis trichomes. showed changes in protein abundance in response to changes in element accumulation. The CAX mutants showed an increased abundance of plasma membrane ATPase and vacuolar H-pumping proteins, and proteins associated with water movement and endocytosis, while also showing changes in proteins associated with the regulation of plasmodesmata. These findings advance our understanding of the integration of CAX transport with elemental homeostasis within trichomes and shed light on how plants modulate protein abundance under conditions of altered elemental levels.

COMPARISON OF OZONATION (O3) AND AOPS (O3/H2O2) IN PURIFICATION OF WELL WATER IN KLUMPRIT VILLAGE, CENTRAL JAVA, INDONESIA

Water is a very important need for human life. The need for clean water has increased due to changes in people's behavior during the COVID-19 pandemic. Despite the increasing need for clean water during the pandemic, access to it remains unequal. One of the areas with poor water sources is Klumprit Village, Nusawungu, Cilacap, Central Java, where the water is cloudy, yellow in color, and a rustic smell. According to the Regulation of Ministry of Health of the Republic of Indonesia Number 32 of 2017, water that is suitable for sanitation needs is water that is odorless, tasteless, not cloudy or has a low level of turbidity. Ozone is an environmentally friendly technology because it does not produce harmful by-products. In addition to ozone, the production of clean water can use Advanced Oxidation Processes (AOPs) with (O3/H2O2). The existence of H2O2 will increase the ability of ozone in the production of clean water or water purification. In this study, ozonation and AOPs (O3/H2O2) were carried out to purify the yellow and cloudy well water in Klumprit Village, Cilacap, Central Java as an effort to improve public health during the COVID-19 pandemic. The research method was to compare ozonation and AOPs (O3/H2O2). The study will include variations in pH levels, specifically neutral pH (untreated sample) and alkaline, as well as different concentrations of H2O2. The experimental data included Fe and Mn content in water before and after the treatment process. Based on the results of this study, it was found that the yellow color of the groundwater in Klumprit village is caused by high levels of manganese (Mn). The lowest concentration of Mn was achieved after 60 minutes of ozonation at an alkaline pH of 9, with a concentration of 0.266 mg/L. The iron (Fe) content showed fluctuation for both treatment methods, ozonation (O3) and advanced oxidation processes (O3/H2O2).

Investigating the Discoloration of Leaves of Dioscorea polystachya Using Developed Atomic Absorption Spectrometry Methods for Manganese and Molybdenum.

The Chinese yam (Dioscorea polystachya, DP) is promising for the food and pharmaceutical industries due to its nutritional value and pharmaceutical potential. Its proper cultivation is therefore of interest. An insufficient supply of minerals necessary for plant growth can be manifested by discoloration of the leaves. In our earlier study, magnesium deficiency was excluded as a cause. As a follow-up, this work focused on manganese and molybdenum. To quantify both minerals in leaf extracts of DP, analytical methods based on atomic absorption spectrometry (AAS) using the graphite furnace sub-technique were devised. The development revealed that the quantification of manganese works best without using any of the investigated modifiers. The optimized pyrolysis and atomization temperatures were 1300 °C and 1800 °C, respectively. For the analysis of molybdenum, calcium proved to be advantageous as a modifier. The optimum temperatures were 1900 °C and 2800 °C, respectively. Both methods showed satisfactory linearity for analysis. Thus, they were applied to quantify extracts from normal and discolored leaves of DP concerning the two minerals. It was found that discolored leaves had higher manganese levels and a lower molybdenum content. With these results, a potential explanation for the discoloration could be found.

Spatial memory impairment is associated with decreased dopamine-β-hydroxylase activity in the brains of rats exposed to manganese chloride

Chronic exposure to manganese compounds leads to accumulation of the manganese in the basal ganglia and hippocampus. High levels of manganese in these structures lead to oxidative stress, neuroinflammation, imbalance of brain neurotransmitters, and hyperactivation of calpains mediating neurotoxicity and causing motor and cognitive impairment. The purpose of this work was to study the effect of excess manganese chloride intake on rats’ spatial memory and on dopamine-β-hydroxylase (DβH) activity under conditions of calpain activity suppression. Rats were divided into 3 groups of 10 animals each. Group 1 received MnCl2 (30 days, 5 mg/kg/day, intranasally), group 2 received MnCl2 (30 days, 5 mg/kg/day, intranasally) and calpain inhibitor Cast (184–210) (30 days, 5 µg/kg/day, intranasally), and group 3 received sterile saline (30 days in a volume of 20 μl, intranasally). The spatial working memory was assessed using Morris water maze test. DβH activity was determined by HPLC. We have shown that in response to excessive intake of MnCl2, there was a development of cognitive impairments in rats, which was accompanied by a decrease in DβH activity in the hippocampus. The severity of cognitive impairment was reduced by inhibiting the activity of m-calpain. The protective effect of calpain inhibitors was achieved not through an effect on DβH activity. Thus, the development of therapeutic regimens for the treatment of manganism using dopaminomimetics and/or by inhibiting calpains, must be performed taking into account the manganese-induced decrease of DβH activity and the inability to influence this process with calpain inhibitors.

Anthropogenic land uses lead to changes in limnological variables in Neotropical streams.

Streams are vulnerable to anthropogenic impacts, such as changes in land use, which reflect on water quality and can be evaluated by abiotic variables. In this context, the aims were to compare the abiotic values recorded in streams of different land use categories with the limits established by National legislation, and to analyze changes in abiotic variables in response to different land use impacts.Thus, 17 streams located in southern Brazil were sampled and grouped into urban, rural, and protected areas (PA) categories. The results showed the major impacts in urban streams. However, some variables in rural streams and PA also exceeded local legislation limits. Conductivity, total dissolved solids, salinity, ammoniacal nitrogen and coliforms were significantly higher in the urban streams. Contrary to expectations, the highest levels of manganese were found in PA streams. The relationship between abiotic variables and land uses suggests possible contamination by sewage in urban streams and by pesticides in rural streams. The abiotic similarity between rural and PA streams indicates that the conservation of these water bodies is ineffective. We suggest the monitoring of these environments and measures to mitigate the impacts to seek the restoration of ecosystem services and the well-being of human populations.

Chemical Fractionation of Manganese in Commercial Coffee Samples from Conventional and Organic Cultivation Systems

Coffee, a source of useful nutrients, is predominantly consumed as an infusion. Because of this, the availability of these nutrients is influenced by their solubility, which could be affected by cultivation methods. This study investigates the impact of Brazilian-regulated organic cultivation practices on manganese. It evaluates total concentration, fractionation, and infusion extractability using semi-selective extraction and flame atomic absorption spectrometry (FAAS) for analysis. The average total manganese concentrations were 45.5 ± 11.2 mg kg−1 in conventional coffee and 64.7 ± 9.2 mg kg−1 in organic coffee. The higher manganese levels in organic coffee may be attributed to soil conditions that are beneficial to organic farming. Principal component analysis revealed distinct differences in manganese fractionation, underscoring the impact of cultivation methods on manganese metabolism and storage. Despite these disparities, the manganese levels in coffee infusions and the fraction available for absorption exhibited no significant variation between conventional and organic cultivation group samples.

Death following cylindrical battery ingestion associated with toxic manganese levels.

Cases of battery ingestion are well documented in the scientific literature, especially concerning button cell battery ingestion in children. In this instance, the authors present an atypical case of a young man who voluntarily ingested a cylindrical alkaline battery containing manganese. The patient died approximately a week later, despite not exhibiting any specific symptoms. The battery was found in the cecum during the autopsy, showing deterioration at its positive pole. The cecal mucosa exhibited two ulcerations without perforation. Histological analysis revealed intestinal ischemia in the cecum, with no microscopic lesions in other organs. Toxicology reports indicated high levels of manganese in both cardiac and peripheral blood. Considering all the results from the additional analyses, the experts concluded that the death was likely of multifactorial origin, associated with a toxic blood concentration of manganese. To the best of our knowledge, this is the first recorded death following the ingestion of a cylindrical battery, and the first instance of manganese intoxication resulting from the ingestion of an alkaline battery. The authors will present the case and provide a literature review to assess the extent to which the presence of manganese may have contributed to the fatality.

A comprehensive monitoring approach for a naturally anoxic aquifer beneath a controlled landfill

The processes leading to high levels of arsenic (As), iron (Fe), and manganese (Mn) in groundwater, in a naturally reducing aquifer at a controlled municipal landfill site, are investigated. The challenge is to distinguish the natural water-rock interaction processes, that allow these substances to dissolve in groundwater, from direct pollution or enhanced dissolution of hydroxides as undesired consequences of the anthropic activities above. Ordinary groundwater monitoring of physical-chemical parameters and inorganic compounds (major and trace elements) was complemented by environmental isotopes of groundwater (tritium, deuterium, oxygen-18 and carbon-13) and dissolved gases (carbon-13 of methane and carbon dioxide and carbon-14 of methane). Pearson/Spearman correlation indices, as well as Principal Component Analysis (PCA), were used to determine the main correlations among variables. The concurrent presence of As, Fe and CH4, as reported in similar anoxic environments, suggests that anaerobic oxidation of methane could drive the reductive dissolution of As-rich Fe(III)(hydro)oxides. Manganese is more sensitive to carbon dioxide, possibly due to a decrease in pH which accelerates the dissolution of Mn-oxides. Finally, we found that tritium and deuterium, which have been used for decades as leachate tracer in groundwater, may be subject to false positives due to the reuse of water recovered from leachate treatment (which has the same isotopic signature of leachate) within the plants, to comply with the requirements of the circular economy. The integration of the environmental isotope analysis into the traditional monitoring approach can effectively support the comprehension of processes. However, this strategy needs to be complemented by a good conceptual hydrogeological model and expert evaluation to avoid misinterpretations.

Biogeochemical mechanisms of iron (Fe) and manganese (Mn) in groundwater and soil profiles in the Zhongning section of the Weining Plain (northwest China)

High levels of Iron (Fe) and manganese (Mn) in soils may contribute to secondary contamination of groundwater. However, there is limited understanding of the cycling mechanisms of Fe and Mn in groundwater and soil. This study aimed to investigate the biogeochemical processes constituting the Fe and Mn cycle by combining hydrochemistry, sequential extraction and microbiological techniques. The results indicated a similar vertical distribution pattern of Fe and Mn, with lower levels of the effective form (EFC-Fe/Mn) observed at the oxygenated surface, increasing near the groundwater table and decreasing below it. Generally, there was a tendency for accumulation above the water table, with Mn exhibiting a higher release potential compared to Fe. Iron‑manganese oxides (Ox-Fe/Mn) dominated the effective forms, with Fe and Mn in the soil entering groundwater through the reduction dissolution of Ox-Fe/Mn and the oxidative degradation of organic matter or sulfide (OM-Fe/Mn). Correlation analysis revealed that Fe and Mn tend to accumulate in media with fine particles and high organic carbon (TOC) contents. 16S rRNA sequencing analysis disclosed significant variation in the abundance of microorganisms associated with Fe and Mn transformations among unsaturated zone soils, saturated zone media and groundwater, with Fe/Mn content exerting an influence on microbial communities. Furthermore, functional bacterial identification results from the FAPROTAX database show a higher abundance of iron-oxidizing bacteria (9.3 %) in groundwater, while iron and manganese-reducing bacteria are scarce in both groundwater and soil environments. Finally, a conceptual model of Fe and Mn cycling was constructed, elucidating the biogeochemical processes in groundwater and soil environments. This study provides a new perspective for a deeper understanding of the environmental fate of Fe and Mn, which is crucial for mitigating Fe and Mn pollution in groundwater.

Trace Elements in Alzheimer's Disease and Dementia: The Current State of Knowledge.

Changes in trace element concentrations are being wildly considered when it comes to neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease. This study aims to present the role that trace elements play in the central nervous system. Moreover, we reviewed the mechanisms involved in their neurotoxicity. Low zinc concentrations, as well as high levels of copper, manganese, and iron, activate the signalling pathways of the inflammatory, oxidative and nitrosative stress response. Neurodegeneration occurs due to the association between metals and proteins, which is then followed by aggregate formation, mitochondrial disorder, and, ultimately, cell death. In Alzheimer's disease, low Zn levels suppress the neurotoxicity induced by β-amyloid through the selective precipitation of aggregation intermediates. High concentrations of copper, iron and manganese cause the aggregation of intracellular α-synuclein, which results in synaptic dysfunction and axonal transport disruption. Parkinson's disease is caused by the accumulation of Fe in the midbrain dopaminergic nucleus, and the pathogenesis of multiple sclerosis derives from Zn deficiency, leading to an imbalance between T cell functions. Aluminium disturbs the homeostasis of other metals through a rise in the production of oxygen reactive forms, which then leads to cellular death. Selenium, in association with iron, plays a distinct role in the process of ferroptosis. Outlining the influence that metals have on oxidoreduction processes is crucial to recognising the pathophysiology of neurodegenerative diseases and may provide possible new methods for both their avoidance and therapy.

Serum and tissue metallome of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) patients have late presentation at the time of diagnosis and a poor prognosis. Metal dyshomeostasis is known to play a role in cancer progression. However, the blood and tissue metallome of PDAC patients has not been assessed. This study aimed to determine the levels of essential and toxic metals in the serum and pancreatic tissue from PDAC patients. Serum samples were obtained from PDAC patients before surgical resection. Tissue (tumor and adjacent normal pancreas) were obtained from the surgically resected specimen. Inductively coupled plasma-mass spectrometry (ICP-MS) analysis was performed to quantify the levels of 10 essential and 3 toxic metals in these samples. Statistical analysis was performed to identify dysregulated metals in PDAC and their role as potential diagnostic and prognostic biomarkers. Significantly decreased serum levels of magnesium, potassium, calcium, iron, zinc, selenium, arsenic, and mercury and increased levels of molybdenum were shown to be associated with PDAC. There were significantly decreased levels of zinc, manganese and molybdenum, and increased levels of calcium and selenium in the pancreatic tumor tissue compared with the adjacent normal pancreas. Notably, lower serum levels of calcium, iron, and selenium, and higher levels of manganese, were significantly associated with a poor prognosis (i.e., overall survival) in PDAC patients. In conclusion, this is the first study to comprehensively assess the serum and tissue metallome of PDAC patients. It identified the association of metals with PDAC diagnosis and prognosis.

Metalloproteomic analysis of liver proteins isolated from broilers fed with different sources and levels of copper and manganese

Supplementing minerals beyond dietary requirements can increase the risk of toxicity and mineral excretion, making the selection of more bioavailable sources crucial. Thus, this work aimed to use metalloproteomics tools to investigate possible alterations in the hepatic proteome of broilers fed with diets containing two sources (sulfate and hydroxychloride) and two levels of copper (15 and 150 ppm) and manganese (80 and 120 ppm), totaling four treatments: low Cu/Mn SO4, high Cu/Mn SO4, low Cu/Mn (OH)Cl and high Cu/Mn (OH)Cl. The difference in abundance of protein spots and copper and manganese concentrations in liver and protein pellets were analyzed by analysis of variance with significance level of 5%. The Cu and Mn concentrations determined in liver and protein pellets suggested greater bioavailability of hydroxychloride sources. We identified 19 Cu-associated proteins spots, 10 Mn-associated protein spots, and 5 Cu and/or Mn-associated protein spots simultaneously. The analysis also indicated the induction of heat shock proteins and detoxification proteins in broilers fed with high levels of copper and manganese, suggesting the involvement of these proteins in metal tolerance and stress.

Increased risk of attention-deficit/hyperactivity disorder in adolescents with high salivary levels of copper, manganese, and zinc

Exposure to toxic heavy metals has been associated with the development of attention-deficit/hyperactivity disorder (ADHD). However, fewer studies have examined the associations between abnormal levels of essential trace metals and ADHD, and none have done so using saliva. We investigated whether salivary metals were associated with ADHD in adolescents aged 12 from the Family Life Project (FLP) using a nested case–control study design that included 110 adolescents who met diagnostic criteria for inattentive (ADHD-I), hyperactive-impulsive (ADHD-H), or combined type ADHD (ADHD-C) (cases) and 173 children who did not (controls). We used inductively coupled plasma optical emission spectrophotometry to measure chromium, copper, manganese, and zinc in saliva samples. We employed logistic regression models to examine associations between quartile levels of individual metals and ADHD outcomes by subtype. Salivary copper levels were significantly associated with increased odds of any ADHD diagnosis (OR = 3.31, 95% CI: 1.08–10.12; p = 0.04) and with increased odds of ADHD-C diagnosis (OR = 8.44, 95% CI: 1.58–45.12; p = 0.01). Salivary zinc levels were significantly associated with increased odds of ADHD-C diagnosis (OR = 4.06, 95% CI: 1.21–13.69; p = 0.02). Salivary manganese levels were also significantly associated with increased odds of ADHD-C diagnosis (OR = 5.43, 95% CI: 1.08–27.27, p = 0.04). This is the first study using saliva to assess metal exposure and provide a potential link between salivary levels of copper, manganese, and zinc and ADHD diagnoses in adolescents. Public health interventions focused on metal exposures might reduce ADHD incidence in low-income, minority communities.

Analysis of the Impact of Coal Mineacid Water on River Water Quality, Biota, and Human Health Around Mining

Acid Mine Drainage (AMD) or Acidic Acidic Drainage (AAT) is a type of water runoff that happens when certain sulfide minerals in rocks come in contact with water and oxygen, triggering an oxidation process that results in water with acidic properties. To understand more about this phenomenon, a literature review was conducted using relevant keywords on online information sources. The indicators used to measure the level of acidity in mine water include pH, metal concentration, Total Suspended Solid (TSS) or turbidity level, electrical conductivity, sulfate, and sulfuric acid content. High electrical conductivity in mine water usually indicates the presence of metals such as iron (Fe) and manganese (Mn). High levels of manganese (Mn) in water can cause health problems for humans. Moreover, an increase in the concentration of Fe can cause an increase in turbidity or TSS because iron metal can dissolve in air and form solid particles that can cause turbidity. To reduce acidity and environmental pollution, passive or active treatment techniques can be used to neutralize AMD.

Diversity and botanical composition of native species in the Pampa biome in vineyards cultivated on soils with high levels of copper, zinc and manganese and phytoremediation potential

Viticulture allows the preservation of native species inside vineyards in the Pampa biome. However, phytosanitary treatments in these areas can increase the levels of Cu, Zn and Mn. The study aimed to (i) verify the influence of Cu, Zn and Mn contents in Pampa biome soils; (ii) identify variables related to Cu, Zn and Mn that most contribute to the variation in richness, diversity, and dry matter production of native vegetation, (iii) investigate the phytoremediation potential of species present in vineyards. Botanical composition, Cu, Zn, Mn available in the soil, and plant nutritional composition in two vineyards (V1 and V2) and native field (NF) were evaluated. Vineyards showed higher Cu, Zn and Mn contents in the soil, resulting in the lowest biomass, richness, and diversity of native species. Mn in tissue was the most important variable in explaining the variation in dry matter. Zn in the soil helped to explain the difference in species richness and diversity. P concentration in tissue was important in elucidating the variation in species diversity. Paspalum plicatulum and Paspalum notatum have potential for phytostabilization of metals in vineyards.

Shotgun metagenomics from Monte Cristo cave (Brazil) reveals microbial metabolic potential related to iron and manganese biogeochemical cycles

Caves are among the most singular and understudied environments on Earth. Due to the harsh conditions observed in many caves, including scarcity of nutrients and low levels of light, these ecosystems are considered extreme environments (Gabriel and Northup 2012). Therefore, it may be worth paying special attention to the microbial communities existing in these unique systems. Previously, it has been suggested that the high levels of Manganese (Mn) and Iron (Fe) at Lechuguilla and Spider Caves in the United States may influence their microbial community structure in different ways (Northup et al. 2003, Carmichael and Bräuer 2015). In this context, caves are promising environments for investigating microbial functional capabilities in relation to these elements and the ecological interactions that allow these microbes to thrive. Monte Cristo cave (MCC) - in Diamantina, Brazil - was chosen for this study. The cave is located in a region known for historic mining activity and occurrences of Mn and Fe-rich rocks (Costa et al. 2003). With that in mind, our main goal is to investigate if within the microbial community of MCC there is evidence of taxa and genes associated with Fe and Mn metabolism. The samples were collected in 2018 from walls and saprolite deposits within MCC. Community DNA from three samples, P1b, P3 and P7, were independently sequenced using Illumina shotgun sequencing, and the data were analysed using conventional metagenomic pipelines and in-house python scripts. Taxonomic classification was assessed using Kraken2; Fe related genes with FeGenie; and Mn related genes were predicted using BlastP against a collection of manually curated Mn-oxidizing proteins. Environmental Mn and Fe concentrations were measured using ICP-OES. Our results suggest the presence of a microbial community potentially able to change Fe and Mn redox states. In sites P1b and P7, genes associated to Fe and Mn oxidation were identified, Fig. 1. Taxonomic evidence for these metabolisms includes the presence of the taxa Comamonadaceae and Hyphomicrobiaceae, both families that were previously reported to harbour species able to oxidize Mn and Fe (Spring and Kämpfer 2015, Carmichael and Bräuer 2015). Our analysis also assigned contigs to the archaeal phyla Crenarchaeota, Euryarchaeota and Thaumarchaeota, whose presence has been associated with oligotrophic caves where archaea play a role in primary production (Ortiz et al. 2013) (Fig. 2). Moreover, the phylum Euryarchaeota harbours members that use Fe or Mn as electron acceptors during methane oxidation (Ettwig et al. 2016). Our results therefore contribute to understanding how microbial communities of MCC may be playing a role in the biogeochemical cycles of Fe and Mn under the conditions imposed by the subterranean environment, which might reflect similar processes in other caves yet to be explored by a metagenomics approach.

The Effectiveness of Zeolite-Activated Charcoal in Reducing Iron and Manganese Levels in Well Water of Milala Housing in Pancur Batu District, North Sumatra

Dug wells are a means of providing clean water that belongs to shallow groundwater and generally contains high levels of iron (Fe) and manganese (Mn). The presence of high levels of iron in water is marked by yellow-brown water color and unpleasant odor. Excess iron can cause poisoning, intestinal damage, premature aging to sudden death, impaired absorption of vitamins and minerals, and hemochromatosis. Based on the observation of the researchers on the condition of the dug well water of the community in Milala Rumah Tengah Block E Simpang Gardu Subdistrict Pancur Batu, it can be seen that the dug well water is very yellow and the community uses it as a source of clean water. The results showed that the iron content of the dug well water in two houses before treatment was &gt;4 mg/l and the manganese content in the first house was 2.60 mg/l and in the second house was 3.02 mg/l. After treatment using activated charcoal zeolite for ten days, the average iron content decreased to 0.08 mg/l (98%) and the average manganese content decreased to 0.26 mg/l (90%)

Remediation of the microecological environment of heavy metal-contaminated soil with fulvic acid, improves the quality and yield of apple

The excessive application of chemical fertilizers and pesticides in apple orchards is responsible for high levels of manganese and copper in soil, and this poses a serious threat to soil health. We conducted a three-year field experiment to study the remediation effect and mechanism of fulvic acid on soil with excess manganese and copper. The exogenous application of fulvic acid significantly reduced the content of manganese and copper in soil and plants; increased the content of calcium; promoted the growth of apple plants; improved the fruit quality and yield of apple; increased the content of chlorophyll; increased the activity of superoxide dismutase, peroxidase, and catalase; and reduced the content of malondialdehyde. The number of soil culturable microorganisms, soil enzyme activity, soil microbial community diversity, and relative abundance of functional bacteria were increased, and the detoxification of the glutathione metabolism function was enhanced. The results of this study provide new insights that will aid the remediation of soil with excess manganese and copper using fulvic acid.