Microbial analysis of cucumbers (Cucumis sativus) produced with tap or treated waste water

There is increasing evidence for a significant role of fruits and vegetables in infectious diseases in humans. Their consumption is increasing and environmental factors such as water availability are impacting their production. In this study, adding fertiliser to tap water (TW) increased the microbial load above that found in treated waste water (TWW); coliforms were also introduced. Low numbers of Bacillus spp. were recovered from inside some healthy cucumber fruits. No visible differences were observed between cucumber plants irrigated with TWW or TW or cucumbers with and without endophytic Bacillus spp. This is noteworthy when considering the use of TWW for crop irrigation.     

Ammonia emissions and biodegradation of organic carbon during sewage sludge composting with different extra carbon sources

Ammonia emissions during composting result in the reduced value of agronomic production and can also pollute the air. To evaluate the influence of various carbon sources on ammonia emissions, six composting experiments were carried out with different amendments of carbon sources (glucose, sucrose and straw powder). The cumulative ammonia volatilizations were reduced from 3.11 g/kg (R6) to 2.46 g/kg (R1), 2.17 g/kg (R2), 2.23 g/kg (R4) and 1.93 g/kg (R5). Compared to the control, no significant difference of ammonia emissions and carbon degradation was observed for the mixture of R3 (3.15 g/kg), which was amended with straw powder alone. The co-addition of sucrose and straw powder led to the lowest ammonia emissions. According to these results, a higher C/N ratio did not necessarily indicate an effective solution for reducing ammonia emissions, and not all readily available carbon compounds were helpful in reducing ammonia emissions. The addition of sucrose promoted the decomposition of organic carbon during the intensive stage of ammonia emissions, and the combination of straw and sucrose prolonged this promotion. Thus, the co-addition of sucrose and straw powder made it possible to reduce ammonia emissions drastically by nitrogen immobilization.     

Analogs of iso-azepinomycin as potential transition-state analog inhibitors of guanase: Synthesis,biochemical screening,and structure–activity correlations of various selectively substituted imidazo[4,5-e][1,4]diazepines

Guanase is an important enzyme of the purine salvage pathway of nucleic acid metabolism and its inhibition has beneficial implications in viral, bacterial, and cancer therapy. The work described herein is based on a hypothesis that azepinomycin, a heterocyclic natural product and a purported transition state analog inhibitor of guanase, does not represent the true transition state of the enzyme-catalyzed reaction as closely as does iso-azepinomycin, wherein the 6-hydroxy group of azepinomycin has been translocated to the 5-position. Based on this hypothesis, and assuming that iso-azepinomycin would bind to guanase at the same active site as azepinomycin, several analogs of iso-azepinomycin were designed and successfully synthesized in order to gain a preliminary understanding of the hydrophobic and hydrophilic sites surrounding the guanase binding site of the ligand. Specifically, the analogs were designed to explore the hydrophobic pockets, if any, in the vicinity of N1, N3, and N4 nitrogen atoms as well as O⁵ oxygen atom of iso-azepinomycin. Biochemical inhibition studies of these analogs were performed using a mammalian guanase. Our results indicate that (1) increasing the hydrophobicity near O⁵ results in a negative effect, (2) translocating the hydrophobicity from N3 to N1 also results in decreased inhibition, (3) increasing the hydrophobicity near N3 or N4 produces significant enhancement of inhibition, (4) increasing the hydrophobicity at either N3 or N4 with a simultaneous increase in hydrophobicity at O⁵ considerably diminishes any gain in inhibition made by solely enhancing hydrophobicity at N3 or N4, and (5) finally, increasing the hydrophilic character near N3 has also a deleterious effect on inhibition. The most potent compound in the series has a K_i value of 8.0 ± 1.5 μM against rabbit liver guanase.     

Effect of carbide sludge (lime) on bioavailability and leachability of heavy metals during rotary drum composting of water hyacinth

Abstract

The bioavailability and leachability of heavy metals play a major role in the toxicity of heavy metals in the compost applied for soil conditioning. A rotary drum composter was used for the study of heavy metal bioavailability and leachability during water hyacinth composting with a mixture of cattle manure, sawdust and lime. Lime was added in 1, 2 and 3% to the mixture of water hyacinth, cattle manure and sawdust at a ratio of 6:3:1 respectively. Influences of physico-chemical parameters on heavy metal bioavailability and leachability were studied during the process. The bioavailability of heavy metals solubility and diethylene triamine penta-acetic acid extractability was examined. The toxicity characteristics leaching procedure (TCLP) test was performed for assessing the hazardous properties of compost. The nutrients and the total concentration of heavy metals were increased during the composting process. The lime was very effective in reducing water solubility, plant availability and leachability of the selected heavy metals (Zn, Cu, Mn, Fe, Ni, Pb, Cd and Cr) during the process. The addition of lime provided a buffer against the decrease in pH and a sufficient amount of Ca that would improve the metabolic activity during composting. The addition of an excess amount of lime slowed the metabolic activity of the microbes due to its high alkalinity. The TCLP test confirms that the heavy metals concentrations in the control and in the lime-amended compost were below the threshold limits.     

Effect of potassium diformate in combination with different amounts and sources of excessive dietary copper on production performance in weaning piglets

Three studies with each 96 weaning piglets were conducted to evaluate the combinatory effect of potassium diformate and high dietary doses of Cu on production performance. In Exp. 1, increasing dietary Cu (25, 75, 125, 175 ppm Cu) were tested at either no or 1.8% potassium diformate. In Exp. 2, rising dietary levels of potassium diformate (0%, 0.6%, 1.2% and 1.8%) were tested at either 25 or 175 ppm Cu. In Exp. 3, a basal dietary Cu content of 15 ppm was compared with dietary Cu levels of 95 or 175 ppm, each of them added as either Cu sulphate or Cu amino acid chelate or Cu formate. Rising dietary additions of potassium diformate and Cu improved weight gain, feed intake and feed conversion rate of piglets. The combination of potassium diformate and Cu failed to act additively at highest dose levels of the two supplements. Cu sulphate was efficient as growth stimulating additive in all 3 experiments, Cu formate failed to stimulate production performance, Cu chelate tended to depress production performance and to increase blood plasma Cu compared to equivalent amounts of Cu from Cu sulphate.     

Metagenomic insights into strategies of carbon conservation and unusual sulfur biogeochemistry in a hypersaline Antarctic lake

Organic Lake is a shallow, marine-derived hypersaline lake in the Vestfold Hills, Antarctica that has the highest reported concentration of dimethylsulfide (DMS) in a natural body of water. To determine the composition and functional potential of the microbial community and learn about the unusual sulfur chemistry in Organic Lake, shotgun metagenomics was performed on size-fractionated samples collected along a depth profile. Eucaryal phytoflagellates were the main photosynthetic organisms. Bacteria were dominated by the globally distributed heterotrophic taxa Marinobacter, Roseovarius and Psychroflexus. The dominance of heterotrophic degradation, coupled with low fixation potential, indicates possible net carbon loss. However, abundant marker genes for aerobic anoxygenic phototrophy, sulfur oxidation, rhodopsins and CO oxidation were also linked to the dominant heterotrophic bacteria, and indicate the use of photo- and lithoheterotrophy as mechanisms for conserving organic carbon. Similarly, a high genetic potential for the recycling of nitrogen compounds likely functions to retain fixed nitrogen in the lake. Dimethylsulfoniopropionate (DMSP) lyase genes were abundant, indicating that DMSP is a significant carbon and energy source. Unlike marine environments, DMSP demethylases were less abundant, indicating that DMSP cleavage is the likely source of high DMS concentration. DMSP cleavage, carbon mixotrophy (photoheterotrophy and lithoheterotrophy) and nitrogen remineralization by dominant Organic Lake bacteria are potentially important adaptations to nutrient constraints. In particular, carbon mixotrophy relieves the extent of carbon oxidation for energy production, allowing more carbon to be used for biosynthetic processes. The study sheds light on how the microbial community has adapted to this unique Antarctic lake environment.     

The sensitivity of water chemistry to climate in a forested,nitrogen-saturated catchment recovering from acidification

Fluxes of major ions and nutrients were measured in the N-saturated mountain forest catchment-lake system of Čertovo Lake (Czech Republic) from 1998 to 2014. The lake has been rapidly recovering from atmospheric acidification due to a 90% decrease in sulphate (SO₄²⁻) deposition since the late 1980s and nitrate (NO₃⁻) contribution to the pool of strong acid anion and leaching of dissolved organic carbon (DOC) have increased. Present concentrations of base cations, phosphorus (P), total organic N (TON), and ionic (Al_i) and organically bound (Al_o) aluminium in tributaries are thus predominantly governed by NO₃⁻ and DOC leaching. Despite a continuing recovery lasting 25 years, the Čertovo catchment is still a net source of protons (H⁺), producing 44 mmol m⁻² yr⁻¹ H⁺ on a catchment-area basis (corresponding to 35 μmol L⁻¹ on a concentration basis). Retention of the deposited inorganic N in the catchment averages 20%, and ammonium consumption (51 mmol m⁻² yr⁻¹) and net NO₃⁻ production (28 mol m⁻² yr⁻¹) are together the dominant terrestrial H⁺ generating processes. In contrast, the importance of SO₄²⁻ release from the soils on terrestrial H⁺ production is continuously decreasing, with an average of 47 mmol m⁻² yr⁻¹ during the study. The in-lake biogeochemical processes reduce the incoming acidity by ∼40%, neutralizing 23 μmol L⁻¹ H⁺ (i.e., 225 mmol m⁻² yr⁻¹ on a lake-area basis). Denitrification and photochemical and microbial decomposition of DOC are the most important in-lake H⁺ consuming processes (50 and 39%, respectively), while hydrolysis of Al_i (from tributaries and photochemically liberated from Al_o) is the dominant in-lake H⁺ generating process. Because the trends in water chemistry and H⁺ balance in the catchment-lake system are increasingly related to variability in NO₃⁻ and DOC leaching, they have become sensitive to climate-related factors (drought, elevated runoff) and forest damage that significantly modify the leaching of these anions. During the study period, increased exports of NO₃⁻ (accompanied by Al_i and base cations) from the Čertovo catchment occurred after a dry and hot summer, after forest damage, and during elevated winter runoff. Increasing DOC export due to decreasing acid deposition was further elevated during years with higher runoff (and especially during events with lateral flow), and was accompanied by P, TON, and Al_o leaching. The climate-related processes, which originally “only” confounded chemical trends in waters recovering from acidification, may soon become the dominant variables controlling water composition in N-saturated catchments.     

Synthesis,anticancer activity,and SAR analyses of compounds containing the 5:7-fused 4,6,8-triaminoimidazo[4,5-e][1,3]diazepine ring system

Described herein are our limited structure–activity relationship (SAR) studies on a 5:7-fused heterocycle (1), containing the 4,6,8-triaminoimidazo[4,5-e][1,3]diazepine ring system, whose synthesis and potent broad-spectrum anticancer activity we reported a few years ago. Our SAR efforts in this study are mainly focused on judicial attachment of substituents at N-1 and N⁶-positions of the heterocyclic ring. Our results suggest that there is some subtle correlation between the substituents attached at the N-1 position and those attached at the N⁶-position of the heterocycle. It is likely that there is a common hydrophobic binding pocket on the target protein that is occupied by the substituents attached at the N-1 and N⁶-positions of the heterocyclic ligand. This pocket appears to be large enough to hold either a C-18 alkyl chain of N⁶ and no attachment at N-1, or a combined C-10 at N⁶ and a CH₂Ph at N-1. Any alkyl chain shorter or longer than C-10 at N⁶ with a CH₂Ph attached at N-1, would result in decrease of biological activity.     

Improvement in the bleaching of kraft pulp with xylanase from Penicillium crustosum FP 11 isolated from the Atlantic forest

Xylanase produced from the newly isolated Penicillium crustosum FP 11 and its potential in the prebleaching of kraft pulp were evaluated using a statistical approach. A Plackett–Burman design (PBD) was carried out to select the significant variables of the medium, these being NaNO₃, KH₂PO₄, MgSO₄, KCl, Fe₂(SO₄)₃, yeast extract, corn stover, and initial pH, in a liquid culture under static conditions for 6 d at 28?°C. Statistical analysis with a central composite design and response surface methodology showed that 0.15% (w/v) KH₂PO₄, 2% (w/v) corn stover, and an initial pH of 6.0 provided the best conditions for xylanase production. Furthermore, xylanase from P. crustosum FP 11 was effective in the bleaching of Eucalyptus kraft pulp, with a significant kappa efficiency of 35.04%. Therefore, the newly isolated P. crustosum FP 11 from the Atlantic Forest biome in Brazil showed two advantages: xylanase production with agricultural residue (corn stover) as a carbon source and an improvement in the bleaching of kraft pulp. Environmental pollution could thus be minimized because of a reduction in the use of chlorine as a bleaching agent.     

Health status of the lizard Podarcis siculus (Rafinesque-Schmaltz, 1810) subject to different anthropogenic pressures

The terrestrial lizard Podarcis siculus is the most abundant reptile in Italy, where is considered a ubiquitous species. This lizard is widely distributed from the islands to the Apennines, from cultivated fields to anthropized areas such as gardens and city parks. For this reason, these animals are exposed to extensive physical and chemical stresses, as well as to the possibility of coming into contact with industrial pollutants and substances used in agricultural practices. Here, we review the health status of lizard specimens inhabiting natural non-anthropized areas and fields devoted to organic farming, considering the condition of (1) liver, representing the main detoxifying organ, directly influenced by feeding, and (2) gonads, essential for reproduction and, therefore, for the survival of the species. The morphological and biomolecular condition of these organs was then compared with those obtained from lizard specimens experimentally treated with nonylphenol, a co-formulant of many insecticides and plant protection products widely used in conventional farming, known to have harmful estrogenic effects. Taken together, data demonstrate that lizards inhabiting manured soil are in good health status and show a regular morphology of liver, testis, and ovary. Animals are found to be less exposed to the toxic heavy metals cadmium and lead if compared with specimens collected in areas not devoted to agriculture, but probably more exposed to vehicular traffic. However, manure, as well as nonylphenol, exerts a xeno-estrogenic effect, particularly evident in male specimens, more sensitive to estrogenic contamination.