Resistance of the alga Spermatozopsis acidophila Kalina (Chlorophyta,Volvocales) to heavy metals

Abstract

The toxic effects of 14 chemical elements (prevalently heavy metals) on the alga Spermatozopsis acidophila Kalina (Volvocales, Polyblepharidaceae) have been investigated.

The results obtained show a high resistance to heavy metals, particularly to Cu, in comparison with data found in literature on other algae.

This phenomenon might be interpreted as a consequence of evolutionary adaptation to highly acid environments.     

Glycaemic and insulinemic response to dietary carbohydrates in horses

Background

Dietary sugar and starch affect plasma glucose and insulin concentrations. Little information is available about the effect of dietary fibre on plasma glucose and insulin concentration. It is hypothesized that different dietary fibre compositions will alter post-prandial glycaemic- and insulinemic index of test meals. The objective was to measure postprandial glucose and insulin concentrations in horses fed meals of different fibre compositions.

Methods

Blood was drawn via jugular vein puncture and the glycaemic and insulinemic index were calculated.

Results

The meal effect on glycaemic and insulinemic response followed the expected pattern, where plasma concentrations increased after feeding and declined after peak concentration. Glycaemic index was 100 (H), 102 (OB), 102 (BB) and 106 (M) and did not differ significantly between meals. Insulinemic index was 100 (H), 140 (OB), 121 (BB) and 125 (M) and did not differ significantly between meals.

Conclusions

In conclusion, meals containing different fibre compositions did not affect the glycaemic- and insulinemic index in horses.

     

Intra-population variation in the diet of an avian top predator: generalist and specialist foraging in Great Black-backed Gulls Larus marinus

ABSTRACT

Capsule: Great Black-backed Gulls Larus marinus breeding on Skokholm, UK, fed predominantly on seabirds, rabbits, refuse, and marine prey, with the majority of pairs being dietary generalists, but with some specialist pairs.

Aims: To understand the significance of Great Black-backed Gulls as top predators on a small offshore island with internationally important numbers of breeding seabirds (Skokholm, UK) by quantifying their diet and to determine how this varies within the breeding season, to test for pair-level dietary specialization and to examine the consequences of dietary differences for reproductive performance.

Methods: Regurgitated pellets were collected and analysed from 26 breeding pairs on Skokholm during 2017 and related to breeding success.

Results: Analysis of 1035 pellets revealed that, overall, Great Black-backed Gulls fed on seabirds (48% – mostly Manx Shearwaters Puffinus puffinus), mammals (38% – mostly European Rabbits Oryctolagus cuniculus), anthropogenic waste (7%), and marine prey (7%). Diet varied among pairs with 18 (73%) generalist pairs and 7 (27%) specialist pairs (of which, 5 were bird specialists and 2 were mammal specialists). Diet also varied seasonally, but pair-level dietary diversity was repeatable through the breeding season. Dietary diversity did not covary with breeding success.

Conclusion: Great Black-backed Gulls are top predators on Skokholm. Variation in diet among pairs emphasizes that not all individuals contribute equally in terms of predation. Understanding the incidence of this variation has important ecological implications, particularly where apex predators may exert a strong top-down influence.     

Cloning of the ferrireductase that may be involved in iron transport in the small intestine: revisiting Crane's controversial oxidoreductase

Abstract

Objectives

Oxidative stress and inflammation have been reported to be higher in subjects with depression, but it is unclear whether this is due to inadequate dietary antioxidant intake or the pathophysiology of depression. The aim of this study was to assess the association between dietary and serum antioxidant status with depression scales in young male university students.

Methods

This research was a case–control study carried out on 60 male university students (30 students diagnosed with depression and 30 matched healthy controls). Beck Depression Inventory-II was used to assess the major depressive disorder (MDD) scales. A semi-quantitative food frequency questionnaire and 2-day 24-h recalls were used for dietary assessment. Dietary and serum total antioxidant capacity (TAC) and high-sensitive C-reactive protein (hs-CRP) concentrations were also measured.

Results

MDD subjects consumed less fruits (P < 0.05), legumes (P < 0.001), nuts and seeds (P = 0.003), vitamin C (P = 0.005), beta carotene (P < 0.001), lutein, and zeaxanthin (P = 0.006) than the controls. Moreover, the depressed group had lower serum TAC levels than their controls (P < 0.05). There were no significant differences in serum hs-CRP concentrations and dietary TAC levels between the study groups.

Discussion

Students with depression had significantly lower intake of dietary antioxidants. However, dietary TAC and serum hs-CRP levels were not significantly different between depressed and normal university male students. Intake of foods rich in antioxidants is encouraged in male students.     

Spatial and temporal variations in the White-tailed Eagle Haliaeetus albicilla breeding diet revealed by prey remains

ABSTRACT

Capsule: Despite its population increase, the White-tailed Eagle Haliaeetus albicilla has not become food-limited, and does not pose a serious threat to birds of conservation concern in the region east of the Baltic Sea.

Aims: We aimed to test variations in the main prey groups and dietary niche breadth of White-tailed Eagles through the years and along an environmental gradient as well as to evaluate the extent of predation on bird species of conservation concern.

Methods: Prey remains were collected during nestling ringing from successful nests located in Lithuania.

Results: The frequency of the prey groups varied along an environmental gradient, with a general pattern of increasing avian prey consumed by pairs breeding in areas with less abundant aquatic habitats. The frequency of alternative prey (i.e. terrestrial birds, mammals) and dietary niche breadth did not increase between 2005 and 2018 and during which time the White-tailed Eagle population nearly doubled. Instead, the occurrence of Northern Pike Esox lucius remains, which was the most frequent single prey species, increased throughout the study period. Bird species of conservation concern constituted only a small fraction of all the prey identified.

Conclusions: The White-tailed Eagle has not become more dependent on alternative prey despite its population increase.     

Temporally explicit abiotic depletion potential (TADP) for mineral resource use based on future demand projections

Purpose

Assessing the potential impacts (characterization) of mineral resource use in life cycle impact assessment (LCIA) has long been debated. One of the most crucial challenges in the characterization models for mineral resource use is the consideration of the changing demand and availability of in-use stocks in the future, which is relevant to the global population and economy growth as well as the increasing low-carbon technologies. We propose an extended characterization model to assess the potential impacts for arbitrary time horizons, considering future demand changes and the availability of in-use stock: temporally explicit abiotic depletion potential (TADP).

Methods

The TADP was developed based on abiotic depletion potential (ADP), which is a widely used characterization model for mineral resource use. While the ADP assesses the potential impacts of mineral resource use based on a natural stock estimate and the current extraction rate, the TADP adopts an average extraction rate for arbitrary time horizons. The average extraction rate was estimated using material flow analysis considering future demand changes and recycling under the five shared socioeconomic pathways (SSPs). TADPs were calculated for six common metals: aluminum, copper, iron, lead, nickel, and zinc.

Results and discussion

As a result of calculating TADPs for the term by 2050 (TADP₂₀₅₀), compared to iron, all other metals showed larger values of characterization factors for all SSPs than the original ADPs. The TADP₂₀₅₀ of copper exhibited the largest difference with ADP among the six metals (approximately 1.9 times), which is mainly attributed to future demand growth. On the other hand, for the longer time perspective, the TADP₂₁₀₀ of lead and zinc exhibited larger differences with ADP than copper (approximately 2.8 times for zinc), which is mainly due to a relatively shorter lifetime for lead and a lower recycling rate for zinc. This suggests that the relative significance of the characterization factors of metals varies depending on the temporal perspective.

Conclusions

With the proposed characterization model, the potential impacts of mineral resource use can be assessed reflecting future situations for the selected time horizons. The results demonstrate that the consideration of future situations greatly influences the relative significance of the potential impacts of using different mineral resources in the results of LCIA studies. By expanding the coverage of mineral resources and future scenario analysis to other relevant factors, the TADP model can improve the robustness of the assessment and further support decision-making towards sustainable resource management.

     

Dietary changes of Mediterranean Shags Phalacrocorax aristotelis desmarestii between the breeding and post-breeding seasons in the upper Adriatic Sea

Capsule?Shags move between breeding and non-breeding areas and this is associated with a significant change in diet.

Aims?To determine whether the diet of Shags nesting on islets off the Croatian coast is the same as their diet after the post-breeding move to the Gulf of Trieste.

Methods?Diet was determined by the analysis of 611 regurgitated food pellets.

Results?A total of 23 988 prey items were identified in the sample of pellets. Post-breeding Shags in the Gulf of Trieste focused on demersal and relatively immobile Gobiidae (81.5% by number, 87.1% by biomass). The most frequent prey species was Gobius niger (70.8% by number). In the breeding season at Oruda island, Croatia, the diet was more varied. Breeding Shags fed on bentho-pelagic, mobile prey such as Atherina boyeri (28.4% in frequency), Serranus hepatus (16.1%) and Crenilabrus tinca (12.0%), while Gobiidae had a dietary frequency of only 18.1%. With respect to biomass the most important prey were Crenilabrus tinca (19.0%) and Serranus hepatus (18.4%).

Conclusion?We suggest that the movement of Shags within the Adriatic Sea is driven by dietary requirements. Most previous studies of Shag diet have shown that Shags tend to have a more specialized diet during the breeding season, concentrating upon demersal prey species. However, we have found that birds breeding at the Croatian study colony show dietary diversity. We suggest that lack of dietary specialization is a facultative response to local prey abundance, and is probably the result of over-fishing of demersal species in the areas around the breeding locations in which the birds find suitable sites and are little disturbed by human activity. Shags may move immediately after breeding to the Gulf of Trieste because demersal species are likely to be more abundant there. As a consequence, the diet becomes more specialized and is then more similar to the diet of other populations of Shags.     

Observations on tolerance to heavy metals of four green algae in relation to pH

Abstract

The inhibition of growth by different concentration of eight heavy metals: Cd, Cr, Co, Cu, Hg, Ni, Se and Tl, in inorganic medium at pH 3 and 6.5, was studied in four green algae: Chlorella protothecoides Krüger, Chlorella saccharophila (Krüger) Migula, Coenochloris sp. and Stichococcus bacillaris Naegeli.

The results suggest that pH has an important effect on heavy metal toxicity in algae although it is difficult to establish a relationship between pH and heavy metals.     

Determination of Human Exposure to Lead and Cadmium: A WHO/UNEP Pilot Study

Abstract

In Stockholm, methods for measuring exposure to lead and cadmium from air, food and beverages were studied in 1988 in a group of 15 non-smoking women, as part of the WHO/UNEP HEAL programme. Airborne particles in the breathing zone air (24-hour samples), duplicate diets (24-hour samples), and faeces (all the stools produced) were collected during 7 consecutive days. Blood was sampled before and immediately after the study period. The results confirmed the need for personal monitoring in the assessment of human exposure to lead and cadmium via air and food. There is need for suitable equipment for 24-hour personal air monitoring. On average, dietary lead (26 μg day^?1, SD 7.9) contributed more than 80% of the total lead uptake, while dietary cadmium (8.5 μg day^?1 SD 2.1) contributed about 99% of the total cadmium uptake. Occasionally consumed foodstuffs with high levels of lead or cadmium seemed to be responsible for a large part of the total weekly intake of lead and cadmium. Fecal lead and cadmium were found to be useful indicators of the total amounts of these metals ingested. Due to the large day-to-day variation observed in the dietary intake of lead and cadmium, the sampling period for duplicate diets and faeces should be at least 5–6 days.     

Effects of feeding on zinc and cadmium accumulation by the polychaete Neanthes arenaceodentata

Abstract

The effects of feeding on the kinetics of accumulation and depuration of ⁶⁵Zn and ¹⁰⁹Cd and on the subcellular distribution of these metals has been studied in the polychaete Neanthes arenaceodentata (Moore). Feeding increases the rate of accumulation of Zn and Cd and decreases the length of time for the metals to reach a steady state concentration in the animals. These effects can be attributed to the adsorption of metals from the medium by the algal food. Feeding does not have a marked effect on the depuration of either of the metals. Both metals are lost in a biphasic manner. The initial phase probably represents the elimination of unassimilated metals from the gut lumen.

Feeding does not dramatically alter the subcellular distribution of the metals. Zinc is found primarily in the 200 g pellet while Cd is primarily found in the cytosol associated with two Cd- binding ligand pools with apparent molecular weights of 9.7 and 5.0 kDa. The former co-elutes with purified metallothionein. The latter contains the majority of the Cd in the cytosol and is prominent in fed organisms. The use of these ligands as subcellular indicators of metal induced stress is discussed.     

Between-species differences in gene copy number are enriched among functions critical for adaptive evolution in Arabidopsis halleri

Background

Gene copy number divergence between species is a form of genetic polymorphism that contributes significantly to both genome size and phenotypic variation. In plants, copy number expansions of single genes were implicated in cultivar- or species-specific tolerance of high levels of soil boron, aluminium or calamine-type heavy metals, respectively. Arabidopsis halleri is a zinc- and cadmium-hyperaccumulating extremophile species capable of growing on heavy-metal contaminated, toxic soils. In contrast, its non-accumulating sister species A. lyrata and the closely related reference model species A. thaliana exhibit merely basal metal tolerance.

Results

For a genome-wide assessment of the role of copy number divergence (CND) in lineage-specific environmental adaptation, we conducted cross-species array comparative genome hybridizations of three plant species and developed a global signal scaling procedure to adjust for sequence divergence. In A. halleri, transition metal homeostasis functions are enriched twofold among the genes detected as copy number expanded. Moreover, biotic stress functions including mostly disease Resistance (R) gene-related genes are enriched twofold among genes detected as copy number reduced, when compared to the abundance of these functions among all genes.

Conclusions

Our results provide genome-wide support for a link between evolutionary adaptation and CND in A. halleri as shown previously for Heavy metal ATPase4. Moreover our results support the hypothesis that elemental defences, which result from the hyperaccumulation of toxic metals, allow the reduction of classical defences against biotic stress as a trade-off.

     

Fatty acid composition of the depot fats of the Polynesian rat,Rattus exulans,Tokelau Islands

The fatty acid composition of the stomach contents, adipose tissue, and perinephric fat of Polynesian rats (Rattus exulans Peale), from the Tokelau Is indicated that the dietary fat consisted mainly, if not exclusively, of coconut oil. Lower ratios of lauric : myristic acids were found in the depot fats of the Polynesian rats than in the dietary coconut oil. These results were consistent with chain elongation of lauric to myristic acid after ingestion, as previously reported in rats and other mammals.     

Determination of chemical species in fly ash collected at different sources

Abstract

Speciation of Cd, Cr, Mn, Ni and Pb in fly ashes derived from iron-smelter works was carried out. Samples were collected at three technological points and subjected to different treatment by strong acids in open vessels and pressurized Teflon bombs. The chemical investigations were completed by X-ray powder diffraction (XRD) method. Determination of toxic metals was performed by atomic adsorption spectrometry. Based on the results it was found that the heavy metals were generally bounded to silicates in the different samples.     

Utilization of Mentha aquatica L. for removal of fecal pathogens and heavy metals from water of Bosna river,Bosnia and Herzegovina

Abstract

The aim of the present study was to investigate the potential of Mentha aquatica L. for phytoremediation of water contaminated with heavy metals and fecal pathogens from Bosna river. The water was treated with M. aquatica for 5, 10, and 15 days consecutively after which it was analyzed for the various physicochemical and microbiological parameters.

The initial concentration of cadmium (Cd) ranged from 3.644 to 6.108?µg/l, while lead (Pb) varied between 0.1 and 1.386?µg/l. After treatment, M. aquatica accumulated significant amounts of cadmium (Cd) and lead (Pb) with the highest removal rates of 96.49% for Cd and 45.72% for Pb. Values of several physicochemical parameters were decreased after 15 days treatment period.

All water samples were analyzed for enumeration of aerobic heterotrophic bacteria, total coliforms, and fecal coliforms by the membrane filtration. Removal efficiency was greater than 80% for microbiological parameters. The concentration of heavy metals was determined in different plant parts and subsequently, the translocation factor was determined. In M. aquatica plant parts, concentrations of Pb and Cd were increased after 15 days of treatment. Our results demonstrated that M. aquatica could be good candidates for the removal of fecal pathogens and heavy metals present in surface water.     

Sequential extraction of trace metals and particle size distribution studies of Kainji Lake sediment,Nigeria

Abstract

Sequential extraction was carried out to determine the concentrations of some trace metals (Mn, Cu, Fe, Pb and Cd) in the Kainji lake sediments from seven different locations in four fractions: exchangeable, bound to iron and manganese oxide, bound to organic matters and residual. This was to undertaken to assess the environmental fate of these trace metals. The BCR technique, a modified form of the Tessier method of sequential extraction was used.

The proportion of the mean metal concentrations of the bioavailable metals follows the order Fe>Cu>Pb>Mn>Cd. Generally, Fe was most abundant metal in the sediment and about 40% was found in its bioavailable form. Although Cd contributed least to the bioavailable content, a greater percentage (~60%) was found in the bioavailable fraction. This suggests that Cd is highly mobile and, since it is known to be toxic, its concentration in the bioavailable form constitutes an environmental threat.

The contribution of metals bound to organic matter was found to be high and of the same magnitude as those bound to oxides and constitutes about 70% of the non-bioavailable metal contents. The petrological analysis of the sediments revealed that the sediments were predominantly quartz and rock clays with percussion marks and indentations.     

Biomonitoring of heavy metals in the coastal waters of two industrialised bays in southern Spain using the barnacle Balanus amphitrite

Abstract

This paper evaluates the bioavailability of As, Cd, Cu, Mn, Hg, Ni and Zn in the coastal waters of the two most important bays in southern Spain (Cádiz and Algeciras). Concentrations of these metals were measured in the bodies of Balanus amphitrite barnacles in 2005 and 2006. Seawater samples were collected from the same sites as the barnacles to assess metal concentrations and to gain additional information on the environmental conditions. Analysis of variance (ANOVA) showed significant geographic differences in the local bioavailability of metals to the barnacles, as reflected in the concentrations of accumulated metals. Balanus amphitrite accumulates large amounts of metals, with high concentration factors for Zn, Cd, Cu and Mn, in relation to the concentrations in marine waters.     

Metabolic response of yellow mealworm larvae to two alternative rearing substrates

Introduction

Bitter melon (Momordica charantia, Cucurbitaceae) is a popular edible medicinal plant, which has been used as a botanical dietary supplement for the treatment of diabetes and obesity in Chinese folk medicine. Previously, our team has proved that cucurbitanes triterpenoid were involved in bitter melon’s anti-diabetic effects as well as on increasing energy expenditure. The triterpenoids composition can however be influenced by changes of varieties or habitats.

Objectives

To clarify the significance of bioactive metabolites diversity among different bitter melons and to provide a guideline for selection of bitter melon varieties, an exploratory study was carried out using a UHPLC-HRMS based metabolomic study to identify chemotypes.

Methods

Metabolites of 55 seed samples of bitter melon collected in different parts of China were profiled by UHPLC-HRMS. The profiling data were analysed with multivariate (MVA) statistical methods. Principle component analysis (PCA) and hierarchical cluster analysis (HCA) were applied for sample differentiation. Marker compounds were identified by comparing spectroscopic data with isolated compounds, and additional triterpenes were putatively identified by propagating annotations through a molecular network (MN) generated from UHPLC-HRMS & MS/MS metabolite profiling.

Results

PCA and HCA provided a good discrimination between bitter melon samples from various origins in China. This study revealed for the first time the existence of two chemotypes of bitter melon. Marker compounds of those two chemotypes were identified at different MSI levels. The combined results of MN and MVA demonstrated that the two chemotypes mainly differ in their richness in cucurbitane versus oleanane triterpenoid glycosides (CTGs vs. OTGs).

Conclusion

Our finding revealed a clear chemotype distribution of bioactive components across bitter melon varieties. While bioactivities of individual CTGs and OTGs still need to be investigated in more depth, our results could help in future the selection of bitter melon varieties with optimised metabolites profile for an improved management of diabetes with this popular edible Chinese folk medicine.

     

Solid-phase distribution of heavy metals as affected by single reagent extraction in dredged sediment derived surface soils

ABSTRACT

EDTA is useful to assess mobile metal pools in polluted soils and sediments. There is a need to enhance our understanding of the significance of metal fractions released. The impact of single reagent extraction with 0.05 mol L^?1 EDTA on the solid phase distribution of trace metals in surface soils sampled from confined dredged sediment disposal sites was investigated. Not extracted and EDTA extracted soils were subjected to sequential extraction to fractionate the total contents into: (1) easily exchangeable and carbonate bound fraction; (2) reducible fraction; (3) oxidisable fraction; and (4) residual fraction. With EDTA, significant portions of metals associated with the acid extractable and reducible fractions were released. The oxidisable and residual fractions remained unaffected for most of the investigated metals except for the organic matter associated metals (Cu and Pb). A decrease in the residual fraction after EDTA-extraction for Cu and Pb was attributed to artifacts of the sequential extraction procedure.     

Numerical Analysis of Faunal Remains of the Little Bethlehem (41AU38) and Leonard K (41AU37) Sites

Abstract

The faunal analysis of the Aliens Creek Area sites presents an interesting analytical problem due to the temporal and spatial proximities. A numerical method was used with the aid of a computer to determine dietary preferences of the peoples who inhabited the sites.     

Stress-driven discovery of a cryptic antibiotic produced by Streptomyces sp. WU20 from Kueishantao hydrothermal vent with an integrated metabolomics strategy

Marine hydrothermal microorganisms respond rapidly to the changes in the concentrations and availability of metals within hydrothermal vent microbial habitats which are strongly influenced by elevated levels of heavy metals. Most hydrothermal vent actinomycetes possess a remarkable capability for the synthesis of a broad variety of biologically active secondary metabolites. Major challenges in the screening of these microorganisms are to activate the expression of cryptic biosynthetic gene clusters and the development of technologies for efficient dereplication of known compounds. Here, we report the identification of a novel antibiotic produced by Streptomyces sp. WU20 isolated from the metal-rich hydrothermal vents in Taiwan Kueishantao, following a strategy based on metal induction of silent genes combined with metabolomics analytical methods. HPLC-guided isolation by tracking the target peak resulted in the characterization of the novel compound 1 with antimicrobial activity against Bacillus subtilis. The stress metabolite 1 induced by nickel is structurally totally different compared with the normally produced compounds. This study underlines the applicability of metal induction combined with metabolic analytical techniques in accelerating the exploration of novel antibiotics and other medically relevant natural products.