Plant community data from a statewide survey of paired serpentine and non-serpentine soils in California, USA

Soils derived from ultramafic parent materials (hereafter serpentine) provide habitat for unique plant communities containing species with adaptations to the low nutrient levels, high magnesium: calcium ratios, and high metal content (Ni, Zn) that characterize serpentine. Plants on serpentine have long been studied in evolution and ecology, and plants adapted to serpentine contribute disproportionately to plant diversity in many parts of the world. In 2000-2003, serpentine plant communities were sampled at 107 locations representing the full range of occurrence of serpentine in California, USA, spanning large gradients in climate. In 2009-2010, plant communities were similarly sampled at 97 locations on nonserpentine soil, near to and paired with 97 of the serpentine sampling locations. (Some serpentine locations were revisited in 2009-2010 to assess the degree of change since 2000-2003, which was minimal.) At each serpentine or nonserpentine location, a north- and a south-facing 50 m x10 m plot were sampled. This design produced 97 “sites” each consisting of four “plots” (north-south exposure, serpentine-nonserpentine soil). All plots were initially visited >3 times over 2 years to record plant diversity and cover, and a subset were revisited in 2014 to examine community change after a drought. The original question guiding the study was how plant diversity is shaped by the spatially patchy nature of the serpentine habitat. Subsequently, we investigated how climate drives plant diversity at multiple scales (within locations, between locations on the same and different soil types, and across entire regions) and at different levels of organization (taxonomic, functional, and phylogenetic).

Natural and Anthropogenic Sources of Cadmium in Cacao Crop Soils in Santander, Colombia

Cadmium (Cd) levels in cacao products from Santander, the main producing area in Colombia, are well above those permitted for export of cocoa products and may pose a potential health hazard. High Cd in cacao is related to the high content of the metal in beans, which in turn is linked to high concentrations of Cd in soils. Geochemical and petrographic analyses of fertilizer, soil and rock samples from three farms were carried out to determine the sources of Cd and soil characteristics that can affect its bioavailability, in order to identify strategies that may reduce Cd in cocoa. Autochthonous natural sources determine the Cd concentration in soils, with a high correlation between elevated Cd in sedimentary parental rocks and soil metal levels. While no industrial or mining inputs were present, an organic fertilizer was identified as a great allochthonous source of Cd in soils. High levels in the fertilizer were probably due to bioaccumulation of the element, since it was sourced from animals in the same area. The addition of crop waste to fertilize the soil may further contribute bioavailable Cd. Even though the pH range, high OM content and presence of Mn and K all diminish bioavailability, the high metal content in the farm soils still results in significant uptake by the cocoa plants and accumulation in the beans. We suggest that phytoremediation and biological amendments, as well as testing of fertilizers before application, could all be cost-effective solutions to reduce Cd levels in the final product.

PSXIII-8 Effects of different sources of Zn on in vitro ruminal fermentation and digestibility of a lactation diet

Vistore® minerals are hydroxychloride minerals that feature high metal content and improved bioavailability. This study was conducted to compare different sources of zinc (Zn) on in vitro rumen fermentation parameters. Three ruminally-cannulated Jersey heifers were adapted to a lactation diet for two weeks before used as donors. Three sources of Zn were tested at 20 ppm: No supplemental Zn (CON), ZnSO4, Vistore Zn, and another Zn hydroxychloride (Vistore-competitor). The concentration of Zn in this study was selected from a titration study (0 to 40 ppm ZnSO4) to identify the minimum concentration of ZnSo4 affecting rumen fermentation. The lactation diet (TMR) was dried and ground to 1mm and used as substrate. Rumen fluid was collected two hours after feeding. Substrate (0.5 g) was inoculated with 100 mL of 3:1 McDougall’s buffer: ruminal flued mixture at 39ºC for 24 h. Each treatment was run in triplicate and in three runs. Data were analyzed with R 3.0. The model included fixed effect of treatment and random effect of run. ZnSO4 reduced (P < 0.05) maximum gas production, DMD (54 vs. 55.9%) and cellulose (27.5 and 40.7%) digestibility. acetate to propionate ration (2.20 vs. 2.24) and NH3-N concentration (6.0 vs. 7.0 mg/dL), increased (P < 0.05) propionate % (27.2 vs 26.7%) compared to control. Vistore had higher pH than control (6.44 vs. 6.40, P = 0.02) but did not affect other parameters compared to CON. Vistore-competitor reduced total VFA production compared to control, ZnSO4, and Vistore (94 vs. 102, 106 and 107 mM, respectively, P = 0.01) but did not affect other parameters. In general, Vistore Zn maintained in vitro ruminal fermentation and digestibility, while ZnSO4 had negative effects on both fermentation and digestibility and Vistore-competitor reduced total VFAs. Results indicate hydroxychloride minerals may stabilize rumen parameters versus sulfate sources but different hydroxychloride sources appear to influence rumen parameters differently.

PSVII-16 Effects of different forms of Cu on in vitro ruminal fermentation and digestibility of a lactation diet

Vistore® mineral products are hydroxychloride minerals that feature high metal content and improved bioavailability. This study was conducted to compare different sources of copper (Cu) on in vitro rumen fermentation parameters. Three ruminally-cannulated Jersey heifers were adapted to a lactation diet for two weeks before being used as donors. Three sources of Cu at 4 ppm: No supplemental Cu (CON), CuSO4, Vistore Cu, and another Cy hydroxychloride product (Vistore-competitor). The concentration of Cu in this study was selected from a titration study (0 to 8 ppm CuSO4) to identify the minimum concentration of CuSO4 affecting rumen fermentation. The lactation diet (TMR) was dried and ground to 1mm and used as the substrate. Rumen fluid was collected two hours after feeding. Substrate (0.5 g) was inoculated with 100 mL of a 3:1 McDougall’s buffer: ruminal fluid mixture at 39ºC for 24 h. Each treatment was run in triplicate and in three runs. Data were analyzed with R 4.0. The model included fixed effect of treatment and random effect of run. CuSO4 tended to increase lag time (0.78 vs -0.57 h, P = 0.06), reduced (P < 0.05) DMD (52.4 vs. 56.1%), cellulose digestibility (4.9% vs. 41.9%), isobutyrate molar % (0.58 vs. 0.78%) and NH3-N concentration (5.46 vs. 6.91 mg/dL). Vistore and Vistore-competitor maintained the fermentation and digestibility compared to CON. In general, Vistore Cu and Vistore-competitor maintained ruminal fermentation and digestibility parameters while negative effects of CuSO4 were observed. These results indicate different Cu mineral sources may affect the rumen differently.

Impact of Tellurite on the Metabolism of Paenibacillus pabuli AL109b With Flagellin Production Explaining High Reduction Capacity

Tellurium (Te) is a metalloid with scarce and scattered abundance but with an increased interest in human activity for its uses in emerging technologies. As is seen for other metals and metalloids, the result of mining activity and improper disposal of high-tech devices will lead to niches with increased abundance of Te. This metalloid will be more available to bacteria and represent an increasing selective pressure. This environmental problem may constitute an opportunity to search for microorganisms with genetic and molecular mechanisms of microbial resistance to Te toxic anions. Organisms from Te-contaminated niches could provide tools for Te remediation and fabrication of Te-containing structures with added value. The objective of this study was to determine the ability of a high metal-resistant Paenibacillus pabuli strain ALJ109b, isolated from high metal content mining residues, to reduce tellurite ion, and to evaluate the formation of metallic tellurium by cellular reduction, isolate the protein responsible, and determine the metabolic response to tellurite during growth. P. pabuli ALJ109b demonstrated to be resistant to Te (IV) at concentrations higher than reported for its genus. It can efficiently remove soluble Te (IV) from solution, over 20% in 8 h of growth, and reduce it to elemental Te, forming monodisperse nanostructures, verified by scattering electron microscopy. Cultivation of P. pabuli ALJ109b in the presence of Te (IV) affected the general protein expression pattern, and hence the metabolism, as demonstrated by high-throughput proteomic analysis. The Te (IV)-induced metabolic shift is characterized by an activation of ROS response. Flagellin from P. pabuli ALJ109b demonstrates high Te (0) forming activity in neutral to basic conditions in a range of temperatures from 20°C to 37°C. In conclusion, the first metabolic characterization of a strain of P. pabuli response to Te (IV) reveals a highly resistant strain with a unique Te (IV) proteomic response. This strain, and its flagellin, display, all the features of potential tools for Te nanoparticle production.

Assessment of water contamination by potentially toxic elements in mangrove lagoons of the Red Sea, Saudi Arabia

Mangrove (Avicennia marina) forests in the Red Sea cost have great concern from environmental, biological, economic, and social points of view. Therefore, assessing water contamination in this ecosystem is worth to be investigated. Consequently, here we aimed to examine the levels of salinity, acidity, and the total content of Fe, Mn, Cu, Zn, Cd, Cr, Ni, and Pb in water samples collected from the upper, middle, and lower part of three mangrove lagoons (i.e., Al-Shuaiba, Yanbu, and Jeddah), Red Sea, Saudi Arabia. The total metal content (µg L−1) in water samples differed significantly among the studied areas and ranged from 286.2 to 4815.0 for Fe, 86.4–483.0 for Mn, 22.9–468.8 for Cu, 199.2–366.6 for Zn, 44.1–99.8 for Cd, 25.6–80.3 for Cr, 11.6–41.5 for Ni, and from 17.7 to 102.0 for Pb. The mean values of Cu, Zn, Cd, and Pb were higher than the WHO water quality standards for fisheries. Water samples in Yanbu were more contaminated and contained higher concentrations of all metals than Jeddah and Al-Shuaiba, due to the petrochemical industries in this industrial area. Our findings suggest that the high metal content in the water of these mangrove sites, particularly in Yanbu, should be considered due to the high potential environmental and human health risks in these ecosystems. These results may help for demonstrating effective approaches for the management of these lagoons. More studies will be carried out on the sediment and mangrove plants in this ecosystem.

Mining Contamination Disrupts Successional Change in Salt Marshes

<p>Salt marshes can generally be considered as sinks for metals. Research into salt marshes in Cornwall, UK suggests those estuaries heavily impacted by mining contamination are characterised by a less diverse vegetation compared with a significantly less-polluted site. Assessment using the National Vegetation Classification on the mid-marsh confirmed an Armeria maritima-dominated community was to be found in the most metal-enriched salt marsh of Restronguet Creek. However, this plant was co-dominant with Plantago maritima in the moderately contaminated marsh of Lelant and not present at all in the Camel, which has been subject to limited mining related contamination. Using canonical correspondence analysis, vegetation abundance data was compared with geochemical variables within the sediment. Metals were studied using extractions to signal bioavailability. P. maritima was not associated with the very high metal levels found in Restronguet Creek. A. maritima, had some association with soluble copper and was closer to the bulk of metals than P. maritima. As tolerance to adverse conditions and competitiveness are mutually exclusive, A. maritima, therefore, exists in a successional relationship with P. maritima. A. maritima then appears to be outcompeted by P. maritima in marshes with low metal loadings. Moderately high metal content results in a loss of competitiveness by P. maritima allowing A. maritima to co-dominate. In extremely metal-rich estuaries, however, P. maritima is unable to compete, allowing A. maritima to colonize the mid-marsh. Vegetation community may, therefore, be useful as an indicator of the level of metal contamination.</p>

Characterization of Algae Dietary Supplements Using Antioxidative Potential, Elemental Composition, and Stable Isotopes Approach

Dietary supplements based on algae, known for their nutritional value and bioactive properties, are popular products among consumers today. While commercial algal products are regarded safe by numerous studies, information about the production and origin of such products is scarce. In addition, dietary supplements are not as strictly regulated as food and medicinal drugs. We characterized different algal products (kelps: Laminariales, Spirulina spp., Chlorella spp., and Aphanizomenon flos-aquae), obtained on Slovenian market, based on their elemental composition (X-ray fluorescence, inductively coupled plasma–mass spectrometry), antioxidative potential [DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, total phenolic content], and stable isotope values [carbon (C), nitrogen (N), and sulfur (S); elemental analyzer isotope ratio mass spectrometry (EA-IRMS) method]. Antioxidative potential is consistent among products of the same type, with A. flos-aquae samples having 4.4 times higher antioxidative potential compared to Chlorella spp. and 2.7 times higher compared to Spirulina spp. Levels of toxic trace elements (arsenic, cadmium, mercury, and lead) are below the maximum allowed values and as such do not pose risk to consumers' health. Samples of Spirulina spp. have relatively high δ15N (7.4 ‰ ± 4.4‰) values, which indicate use of organic nitrogen sources in certain samples. Likewise, different elemental composition and isotopic ratios of stable elements (C, N, and S) for the samples with Spirulina spp. or Chlorella spp. are the consequence of using different nutrient sources and algae-growing techniques. Statistical analysis (principal component analysis) has confirmed that all tested A. flos-aquae samples originate from the same source, supposedly Klamath Lake (Oregon, USA). Hawaiian Spirulina pacifica can also be differentiated from all the other samples because of its characteristically high metal content (iron, manganese, zinc, cobalt, nickel, vanadium). Chlorella spp. and Spirulina spp. require further analyses with larger number of samples, as differentiation is not possible based on results of this study.

BIOGEOCHEMISTRY OF NICKEL DURING IRRIGATION

The geochemical feature of the study area is the enrichment of soil-forming and underlying rocks with Ni, and, as a consequence, a high metal content in groundwater and surface sources, the water of which is used for irrigation. The regular supply of the element with irrigation water leads to an increase in the total content of Ni and its exchange compounds in the upper humus horizons of the studied leached chernozems. Irrigation contributes to the accumulation of Ni in grain and phytomass of crop production. It is shown that long-term irrigation leads to the transformation of organic matter, a change in the pH of the soil solution and the values of hydrolytic acidity.