Phytochemical Combination Is More Effective than Individual Components in Reducing Stress Signaling in Rat Hippocampal Neurons and Microglia In Vitro.

Age-related decrements in the central nervous system (CNS) are thought to result from: (1) increased susceptibility to and accumulating effects of free radicals and inflammation; and (2) dysregulation in Ca2+ homeostasis, which affects numerous signaling pathways. Certain bioactive phytochemicals exhibit potent anti-inflammatory activities which may mitigate these age-related CNS decrements. This study investigated the individual and combination effects of green tea catechin (epigallocatechin gallate, EGCG), curcumin from turmeric, and broccoli sprouts which contain the isothiocyanate sulforaphane on inflammation and dysregulation in Ca2+ homeostasis to determine if the individual compounds were working synergistically and/or through independent mechanisms. Rat hippocampal neurons or highly aggressive proliferating immortalized (HAPI) microglial cells were pre-treated for a week with either the individual components or all in combination before inducing Ca2+ buffering deficits with dopamine (DA, 0.1 µM for 2 h) or inflammation using lipopolysaccharide (LPS, 100 ng/mL for 18 h), respectively. The EGCG (3 µM) and combination protected against DA-induced deficits in Ca2+ buffering (both % of cells that recovered and recovery time, p < 0.05). Additionally, the EGCG and combination reduced stress-mediated inflammation in HAPI rat microglial cells by attenuating LPS-induced nitrite release, inducible nitrous oxide synthase (iNOS) expression, and tumor necrosis factor-alpha (TNF-α) release (p < 0.05), but not cyclooxygenase-2 (COX-2) expression. Overall, broccoli sprouts (2 µM) and curcumin (1 µM) were not as effective as the EGCG or combination. Further research is needed to determine if dietary intervention with a variety of foods containing compounds such as those found in green tea, turmeric, or broccoli sprouts can play a role in reducing age-related CNS inflammation, microglial activation, and downstream signaling pathways that can lead to neuronal dysfunction.

Growth, hemato-biochemical, immune-antioxidant response, and gene expression in Nile tilapia (Oreochromis niloticus) received nano iron oxide-incorporated diets.

Nanotechnology has recently played a key role in tackling many aquacultures issues. Hence, the present study targets the evaluation of dietary inclusion of nano iron oxide (nFe2O3) on growth performance, hematology, immune-antioxidant responses, ionic regulation and expression of related genes in Nile tilapia (Oreochromis niloticus). Fish were fed supplementary nFe2O3 at rates of zero (control), 0.5, and 1 g/kg diet for 30 days. Obtained data demonstrated that nFe2O3 significantly (P < 0.05) augmented growth performance (final weight and length, body mass gain, specific growth rate, feed conversion ratio, and length gain rate). Hematological picture {RBCs, Hb, MCV, MCH and MCHC, and leukocytes interpretations (WBCs and monocytes)}; and biochemical indexes including (AST and ALT; total protein; and glucose, and cortisol) were significantly (P < 0.05) improved in nFe2O3 supplemented groups. Plasma ionic concentration was also altered with nFe2O3 supplementation, and 1g nFe2O3 revealed the most marked increase in plasma (Na+) potassium (K+) levels. Similarly, IgM, nitrous oxide (NO), and lysozyme activity, plus superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities showed a remarkable improvement in 1g nFe2O3 group compared to the control. Expression of Insulin-Like Growth Factor-1 (IGF-1) and interleukin 1-ß (IL-1ß) genes were significantly up-regulated in nFe2O3 supplemented groups. Briefly, dietary nFe2O3 inclusion had enhanced properties on growth; hemato-biochemical; immune, antioxidative profiles; and related genes expression of O. niloticus, with a recommended concentration of 1g nFe2O3.

Microplastics alter nitrous oxide production and pathways through affecting microbiome in estuarine sediments.

Increasing microplastics (MPs) pollution in estuaries profoundly impacts microbial ecosystems and biogeochemical processes. Nitrous oxide (N2O), a powerful greenhouse gas, is an important intermediate product of microbial nitrogen cycling. However, how MPs regulate N2O production and its pathways remain poorly understood. Here, impacts of traditional petroleum-based and emerging biodegradable MPs on microbial N2O production and its pathways were studied through dual-isotope (15N-18O) labeling technique and molecular methods. Results indicated that both traditional petroleum-based and emerging biodegradable MPs promoted sedimentary N2O production, whereas pathways varied. Biodegradable polylactic acid (PLA) MPs displayed greater promotion of N2O production than petroleum-based MPs, polyvinyl chloride (PVC) and polyethylene (PE), of which PLA promoted through nitrifier nitrification (NN) and heterotrophic denitrification (HD), PE through nitrifier denitrification and HD, and PVC through NN. By combining the analysis of N2O production rates with sediment chemical and microbiological properties, we demonstrated that the enrichment of nitrifying and denitrifying bacteria, as well as related functional genes directly and/or indirectly increased N2O production primarily by interacting with carbon and nitrogen substrates. Different response of nitrogen cycling microbes to MPs led to the difference in N2O increase pathways, of which nitrifying bacteria significantly enriched in all MPs treatments due to the niches provided by MPs. However, part of denitrifying bacteria significantly enriched in treatments containing PLA and PE MPs, which may serve as organic carbon substrates. This work highlights that the presence of MPs can promote sedimentary N2O production, and the emerging biodegradable MPs represented by PLA may have a greater potential to enhance estuarine N2O emissions and accelerate global climate change.

Characterization of Denitrifying Community for Application in Reducing Nitrogen: a Comparison of nirK and nirS Gene Diversity and Abundance.

Studies have shown that the addition of biochar to agricultural soils has the potential to mitigate climate change by decreasing nitrous oxide (N2O) emissions resulting from denitrification. Rice paddy field soils have been known to have strong denitrifying activity, but the response of microbes to biochar for weakening denitrification in rice paddy field soils is not well known. In this work, compared with the chemical fertilizer alone, the chemical fertilizer + 20 t hm-2 biochar fertilizer slightly decreased denitrifying the nitrite reductase activity (S-NiR) and N2O emission without statistic difference, whereas the chemical fertilizer + 40 t hm-2 biochar significantly boosted them. The abundance of nir-denitrifiers contributed to S-NiR and N2O emission, especially nirS-denitrifiers, rather than the variation of community structure. Pearson correlation analysis showed that NO2--N was a key factor for controlling the abundance of nir-denitrifiers, S-NiR and N2O emission. The biochar addition fertilization treatments strongly shaped the community structure of nirK-denitrifiers, while the community structure of nirS-denitrifiers remained relatively stable. In addition, Paracoccus and Sinorhizobium were revealed to be as the predominant lineage of nirS- and nirK-containing denitrifiers, respectively. Distance-based redundancy analysis (db-RDA) showed that changes in the nir-denitrifier community structure were significantly related to soil organic carbon, NO3--N, and total phosphorus. Our findings suggest that, although the nirS- and nirK-denitrifiers are both controlling nitrite reductase, their responses to biochar addition fertilization treatments showed significant discrepancies of diversity, abundance, and contribution to N2O and S-NiR in a paddy soil.

Measured greenhouse gas budgets challenge emission savings from palm-oil biodiesel.

The potential of palm-oil biofuels to reduce greenhouse gas (GHG) emissions compared with fossil fuels is increasingly questioned. So far, no measurement-based GHG budgets were available, and plantation age was ignored in Life Cycle Analyses (LCA). Here, we conduct LCA based on measured CO2, CH4 and N2O fluxes in young and mature Indonesian oil palm plantations. CO2 dominates the on-site GHG budgets. The young plantation is a carbon source (1012 ± 51 gC m-2 yr-1), the mature plantation a sink (-754 ± 38 gC m-2 yr-1). LCA considering the measured fluxes shows higher GHG emissions for palm-oil biodiesel than traditional LCA assuming carbon neutrality. Plantation rotation-cycle extension and earlier-yielding varieties potentially decrease GHG emissions. Due to the high emissions associated with forest conversion to oil palm, our results indicate that only biodiesel from second rotation-cycle plantations or plantations established on degraded land has the potential for pronounced GHG emission savings.

Paenibacillus polymyxa biofertilizer application in a tea plantation reduces soil N2O by changing denitrifier communities.

Increasing the use of nitrogen fertilizers in tea orchards has led to intense nitrous oxide (N2O) emissions. Foliar application of Paenibacillus polymyxa biofertilizer has been proven to be beneficial for organic tea production. In this study, tea yield and quality were significantly improved after application of P. polymyxa biofertilizer compared with the control but were not significantly different from chemical fertilizer treatments. However, the average N2O fluxes in tea fields treated with chemical fertilizers and biofertilizers (225 kg N·ha-1·year-1 for both) were 50.6-973.7 and 0.6-29.1 times higher than those in the control treatment, respectively. Pot experiments conducted to explore the mechanism of N2O reduction induced by P. polymyxa biofertilizer showed that applying P. polymyxa in addition to urea could reduce N2O fluxes by 36.5%-73.1%. Quantitative PCR analysis suggested that a significant increase in the quantity of nirK and nosZ genes was linked to the reduction of N2O, and high-throughput sequencing of nosZ revealed active and potentially efficient denitrifiers in different treatments. Our findings suggest that P. polymyxa biofertilizer is in line with the requirements of modern agriculture, which aims to increase product yield and quality while reducing negative environmental impacts.

Biochar amendment and water stress alter rhizosphere carbon and nitrogen budgets in bauxite-processing residue sand under rehabilitation.

Nitrogen (N) bioavailability is one of the main limiting factors for microbial activity and vegetation establishment in bauxite-processing residue sand (BRS). Although beneficial effects of biochar on reducing N loss in the early stages of BRS rehabilitation have been observed previously, the underlying mechanisms of this complicated process, particularly the interactions between applied biochar and the plant rhizosphere is largely unknown. This glasshouse study (116 days), investigated the coupled effects of biochar and water stress on N bioavailability in the rhizosphere of ryegrass (Lolium rigidum) grown in BRS amended with di-ammonium phosphate (DAP) fertiliser (at rates of 0 or 2.7 t ha-1) with and without biochar amendment. The applied biochar was characterised as either aged acidic (AC) or alkaline pine (PC) and was mixed with BRS at a rate of 5% v/v under four moisture regimes (50%, 40%, 20% and 7.5% water holding capacity). Amending BRS with AC and PC biochars increased NH4+ retention and decreased cumulative NH3 volatilization within both the rhizosphere and root-free zones compared with fertiliser only treatment. These effects were more pronounced for the AC than PC biochar, suggesting that aged acidic biochar has the great potential for use in rapid establishment of vegetation in BRS disposal areas. The biochar amendment increased cumulative nitrous oxide emissions compared with DAP only treatment, with no significant differences among different moisture regimes. The Control and 20% water holding capacity (WHC) treatment showed the highest dissolved organic carbon (DOC) concentrations compared with other treatments and moisture regimes in the ryegrass rhizosphere, while the highest dissolved organic N concentration were observed in the DAP + AC treatment. Reducing moisture levels below 20% WHC generally decreased microbial biomass carbon (MBC) concentrations and activity in both the rhizosphere and root-free zones of all treatments, while total N generally decreased as moisture levels decreased from 50% to 7.5% WHC. Plant took up more N in the DAP + AC treatment compared with DAP + PC and DAP only treatments, while increasing water stress generally resulted in decreased aboveground biomass.

Effect of Free Nitrous Acid on Nitrous Oxide Production and Denitrifying Phosphorus Removal by Polyphosphorus-Accumulating Organisms in Wastewater Treatment.

The inhibition of free nitrous acid (FNA) on denitrifying phosphorus removal has been widely reported for enhanced biological phosphorus removal; however, few studies focus on the nitrous oxide (N2O) production involved in this process. In this study, the effects of FNA on N2O production and anoxic phosphorus metabolism were investigated using phosphorus-accumulating organisms (PAOs) culture highly enriched (91 ± 4%) in Candidatus Accumulibacter phosphatis. Results show that the FNA concentration notably inhibited anoxic phosphorus metabolism and phosphorus uptake. Poly-ß-hydroxyalkanoate (PHA) degradation was completely inhibited when the FNA concentration was approximately 0.0923 mgHNO2-N/L. Higher initial FNA concentrations (0.00035 to 0.0103 mgHNO2-N/L) led to more PHA consumption/TN (0.444 to 0.916 mmol-C/(mmol-N·gVSS)). Moreover, it was found that FNA, rather than nitrite and pH, was likely the true inhibitor of N2O production. The highest proportion of N2O to TN was 78.42% at 0.0031 mgHNO2-N/L (equivalent to 42.44 mgNO2-N/L at pH 7.5), due to the simultaneous effects of FNA on the subsequent conversion of NO2 into N2O and then into N2. The traditional nitrite knee point can only indicate the exhaustion of nitrite, instead of the complete removal of TN.

Modeling nitrous oxide production by a denitrifying-enhanced biologically phosphorus removing (EBPR) activated sludge in the presence of different carbon sources and electron acceptors.

In this study, the IWA Activated Sludge Model No. 2d (ASM2d) was expanded to identify the most important mechanisms leading to the anoxic nitrous oxide (N2O) production in the combined nitrogen (N) and phosphorus (P) removal activated sludge systems. The new model adopted a three-stage denitrification concept and was evaluated against the measured data from one/two-phase batch experiments carried out with activated sludge withdrawn from a local, large-scale biological nutrient removal wastewater treatment plant. The experiments were focused on investigating the effects of different external carbon sources (acetate, ethanol) and electron acceptors (nitrite, nitrate) on the mechanisms of N2O production in enhanced biological P removal by polyphosphate accumulating organisms (PAOs) and external carbon-based denitrification by ordinary heterotrophic organisms (OHOs). The experimental results explicitly showed that N2O production was predominantly governed by the presence of nitrite in the reactor regardless of the examined carbon source and the ratio COD/N in the reactor. The model was capable of accurately predicting (with R2 > 0.9) the behavior of not only N2O-N, but also NO3-N, NO2-N, soluble COD, and PO4-P. The simulation results revealed that only OHOs were responsible for N2O production, whereas the present denitrifying PAOs reduced only nitrate to nitrite.

Denitrifying capabilities of Tetrasphaera and their contribution towards nitrous oxide production in enhanced biological phosphorus removal processes.

Denitrifying enhanced biological phosphorus removal (EBPR) systems can be an efficient means of removing phosphate (P) and nitrate (NO3-) with low carbon source and oxygen requirements. Tetrasphaera is one of the most abundant polyphosphate accumulating organisms present in EBPR systems, but their capacity to achieve denitrifying EBPR has not previously been determined. An enriched Tetrasphaera culture, comprising over 80% of the bacterial biovolume was obtained in this work. Despite the denitrification capacity of Tetrasphaera, this culture achieved only low levels of anoxic P-uptake. Batch tests with different combinations of NO3-, nitrite (NO2-) and nitrous oxide (N2O) revealed lower N2O accumulation by Tetrasphaera as compared to Accumulibacter and Competibacter when multiple electron acceptors were added. Electron competition was observed during the addition of multiple nitrogen electron acceptors species, where P uptake appeared to be slightly favoured over glycogen production in these situations. This study increases our understanding of the role of Tetrasphaera-related organisms in denitrifying EBPR systems.

Effects of influent COD/N ratios on nitrous oxide emission in a sequencing biofilm batch reactor for simultaneous nitrogen and phosphorus removal.

The characteristics of N2O emissions from an anaerobic/aerobic/anoxic (A/O/A) sequencing biofilm batch reactor (SBBR) were investigated under different influent COD/nitrogen (C/N) ratios (from 1-4). Results indicated that the C/N ratios affected the quantity of polyhydroxybutyrate (PHB) and residual organic substances after the anaerobic period, resulting in the largest N2O emission during aerobic period occurred at a C/N of 2. Moreover, during the anoxic PHB-driven denitrification period, the rapid decline in the dissolved N2O concentration indicated that the nitrite inhibition threshold for N2O reduction increased with the increased C/N ratios, which means the higher influent C/N ratios could lower the inhibition of nitrite on N2O reduction. Finally, more PHB and residual organic substances were provided to denitrification at a high C/N ratio, resulting in less total N2O emission was achieved at a high C/N ratio in the A/O/A SBBR.

Anxiety-like behavioural effects of extremely low-frequency electromagnetic field in rats.

In recent years, extremely low-frequency electromagnetic field (ELF-EMF) has received considerable attention for its potential biological effects. Numerous studies have shown the role of ELF-EMF in behaviour modulation. The aim of this study was to investigate the effect of short-term ELF-EMF (50 Hz) in the development of anxiety-like behaviour in rats through change hypothalamic oxidative stress and NO. Ten adult male rats (Wistar albino) were divided in two groups: control group-without exposure to ELF-EMF and experimental group-exposed to ELF-EMF during 7 days. After the exposure, time open field test and elevated plus maze were used to evaluate the anxiety-like behaviour of rats. Upon completion of the behavioural tests, concentrations of superoxide anion (O2·-), nitrite (NO2-, as an indicator of NO) and peroxynitrite (ONOO-) were determined in the hypothalamus of the animals. Obtained results show that ELF-EMF both induces anxiety-like behaviour and increases concentrations of O2·- and NO, whereas it did not effect on ONOO- concentration in hypothalamus of rats. In conclusion, the development of anxiety-like behaviour is mediated by oxidative stress and increased NO concentration in hypothalamus of rats exposed to ELF-EMF during 7 days.

Effect of different rates of spent coffee grounds (SCG) on composting process, gaseous emissions and quality of end-product.

The use of spent coffee grounds (SCG) in composting for organic farming is a viable way of valorising these agro-industrial residues. In the present study, four treatments with different amounts of spent coffee grounds (SCG) were established, namely, C0 (Control), C10, C20 and C40, containing 0, 10, 20 and 40% of SCG (DM), respectively; and their effects on the composting process and the end-product quality characteristics were evaluated. The mixtures were completed with Acacia dealbata L. shoots and wheat straw. At different time intervals during composting, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions were measured and selected physicochemical characteristics of the composts were evaluated. During the composting process, all treatments showed a substantial decrease in total phenolics and total tannins, and an important increase in gallic acid. Emissions of greenhouse gases were very low and no significant difference between the treatments was registered. The results indicated that SCG may be successfully composted in all proportions. However C40, was the treatment which combined better conditions of composting, lower GHG emissions and better quality of end product.

Nitrous oxide from moving bed based integrated fixed film activated sludge membrane bioreactors.

The present paper reports the results of a nitrous oxide (N2O) production investigation in a moving bed based integrated fixed film activated sludge (IFAS) membrane bioreactor (MBR) pilot plant designed in accordance with the University of Cape Town layout for biological phosphorous removal. Gaseous and liquid samples were collected in order to measure the gaseous as well as the dissolved concentration of N2O. Furthermore, the gas flow rate from each reactor was measured and the gas flux was estimated. The results confirmed that the anoxic reactor represents the main source of nitrous oxide production. A significant production of N2O was, however, also found in the anaerobic reactor, thus indicating a probable occurrence of the denitrifying phosphate accumulating organism activity. The highest N2O fluxes were emitted from the aerated reactors (3.09 g N2ON m-2 h-1 and 9.87 g N2ON m-2 h-1, aerobic and MBR tank, respectively). The emission factor highlighted that only 1% of the total treated nitrogen was emitted from the pilot plant. Furthermore, the measured N2O concentrations in the permeate flow were comparable with other reactors. Nitrous oxide mass balances outlined a moderate production also in the MBR reactor despite the low hydraulic retention time. On the other hand, the mass balance showed that in the aerobic reactor a constant consumption of nitrous oxide (up to almost 15 mg N2O h-1) took place, due to the high amount of stripped gas.

Differential effects of crude oil on denitrification and anammox, and the impact on N2O production.

Denitrification and anammox are key processes for reducing the external nitrogen loads delivered to coastal ecosystems, and these processes can be affected by pollutants. In this study, we investigated the effect of crude oil on denitrification and anammox. Controlled laboratory experiments were performed using sediment slurries from the Lima Estuary (NW Portugal). Anammox and denitrification rates were measured using (15)N-labeled NO3(-), and the production of (29)N2 and (30)N2 quantified by membrane inlet mass spectrometry. Results revealed that while denitrification rates were stimulated between 10 and 25 000 times after crude oil amendment, anammox activity was partially (between 2 and 5 times) or completely inhibited by the addition of crude oil when comparing to rates in unamended controls. Similar results were observed across four estuarine sediment types, despite their different physical-chemical characteristics. Moreover, N2O production was reduced by 2-36 times following crude oil addition. Further work is required to fully understand the mechanism(s) of the observed reduction in N2O production. This study represents one of the first contributions to the understanding of the impact of crude oil pollution on denitrification and anammox, with profound implications for the management of aquatic ecosystems regarding eutrophication (N-removal).

Antidepressant-like effect of the saponins part of ethanol extract from SHF.

ETHNOPHARMACOLOGICAL RELEVANCE: Suanzaorenhehuan Formula (SHF) has been used for treating depression-like disorders for many years in China. The saponins part of the SHF (SSHF) extract was the antidepressant effective component. AIM OF STUDY: To investigate the antidepressant-like effect of SSHF and its possible mechanisms. MATERIALS AND METHODS: Experimental approaches including the forced swim test (FST), the tail suspension test (TST) and unpredictable chronic mild stress (UCMS) were used to evaluate the effects of SSHF. The possible mechanisms were explored by measuring monoamine neurotransmitter in mice frontal cortex and hippocampus, testing monoamine oxidase enzyme (MAO) activities, antioxidant enzyme activities and free radicals levels in the brains of UCMS-exposed mice. RESULTS: The results showed that SSHF (10, 20, 40mg/kg) significantly decreased the immobility period in FST and TST in mice after two-week treatment. Whereas, SSHF had no significant effect on locomotor activity in mice. It was also found that the serotonin (5-HT) and noradrenaline (NE) levels in the hippocampus and frontal cortex were significantly increased only in 40mg/kg SSHF treated mice. In addition, SSHF (10, 20, 40mg/kg) significantly inhibited monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B) after 21-day UCMS exposure. SSHF (10, 20, 40mg/kg) significantly decreased the nitrous oxide (NO) levels, and increased the activities of total antioxidant capability (T-AOC), glutathione peroxidase (GSH-PX), and catalase (CAT) in different degrees in the brains of UCMS-exposed mice. CONCLUSIONS: Our results suggested that SSHF may effectively produce an antidepressant-like effect, which appeared to involve the serotonergic, noradrenergic, monoamine oxidase enzyme and antioxidant systems.

Comparative activities of milk components in reversing chronic colitis.

Inflammatory bowel disease (IBD) is a poorly understood chronic immune disorder for which there is no medical cure. Milk and colostrum are rich sources of bioactives with immunomodulatory properties. Here we compared the therapeutic effects of oral delivery of bovine milk-derived iron-saturated lactoferrin (Fe-bLF), angiogenin, osteopontin (OPN), colostrum whey protein, Modulen IBD (Nestle Healthsciences, Rhodes, Australia), and cis-9,trans-11 conjugated linoleic acid (CLA)-enriched milk fat in a mouse model of dextran sulfate-induced colitis. The CLA-enriched milk fat significantly increased mouse body weights after 24d of treatment, reduced epithelium damage, and downregulated the expression of proinflammatory cytokines and nitrous oxide. Modulen IBD most effectively decreased the clinical score at d 12, and Modulen IBD and OPN most effectively lowered the inflammatory score. Myeloperoxidase activity that denotes neutrophil infiltration was significantly lower in mice fed Modulen IBD, OPN, angiogenin, and Fe-bLF. A significant decrease in the numbers of T cells, natural killer cells, dendritic cells, and a significant decrease in cytokine expression were observed in mice fed the treatment diets compared with dextran sulfate administered mice. The Fe-bLF, CLA-enriched milk fat, and Modulen IBD inhibited intestinal angiogenesis. In summary, each of the milk components attenuated IBD in mice, but with differing effectiveness against specific disease parameters.

Antidiarrhoeal investigation of Apium leptophyllum (Pers.) by modulation of Na+K+ATPase, nitrous oxide and intestinal transit in rats.

BACKGROUND: Apium leptophyllum (Pers.) is an annual herb with traditional appreciation for various pharmacological properties; however, the scientific information on this herb is insufficient. The aim of the present investigation was undertaken to evaluate flavonoidal fraction of A. leptophyllum fruit (FFALF) against diarrhoea on albino rats. METHODS: The antidiarrhoeal study was conducted by castor oil induce diarrhoea, prostaglandin E2 (PGE2) induced enteropooling and intestinal transit by charcoal meal test. The rats were divided into five groups (six/group). Group I served as control and received orally 2% acacia suspension; Group II served as standard and received orally loperamide (3 mg/kg) or atropine sulphate (5 mg/kg); Group III, IV and V served as test groups and received the FFALF at doses of 5, 10 and 20 mg/kg orally, respectively. RESULTS: In castor oil-induced diarrhoeal model, the FFALF significantly (p < 0.001) reduced the frequency of diarrhoea, defecation and weight of faeces as well as increased the sodium-potassium ATPase (Na+K+ATPase) activity and decreased nitric oxide (NO) content in the small intestine. In prostaglandin induced enteropooling model, it significantly (p < 0.01) and dose dependently slowed the intestinal fluid accumulation by decreasing the masses and volumes of intestinal fluid where as in charcoal meal test, it decreased charcoal meal transit in gastrointestinal tract as compared with control. CONCLUSIONS: The study reveals that the FFALF possess anti-diarrhoeal properties mediated through inhibition of hyper secretion and gastrointestinal motility which support the traditional use of the plant.

Acidophilic denitrifiers dominate the N2O production in a 100-year-old tea orchard soil.

Aerobic denitrification is the main process for high N2O production in acid tea field soil. However, the biological mechanisms for the high emission are not fully understood. In this study, we examined N2O emission and denitrifier communities in 100-year-old tea soils with four pH levels (3.71, 5.11, 6.19, and 7.41) and four nitrate concentration (0, 50, 200, and 1000 mg kg(-1) of NO3 (-)-N) addition. Results showed the highest N2O emission (10.1 mg kg(-1) over 21 days) from the soil at pH 3.71 with 1000 mg kg(-1) NO3 (-) addition. The N2O reduction and denitrification enzyme activity in the acid soils (pH <7.0) were significantly higher than that of soils at pH 7.41. Moreover, TRF 78 of nirS and TRF 187 of nosZ dominated in soils of pH 3.71, suggesting an important role of acidophilic denitrifiers in N2O production and reduction. CCA analysis also showed a negative correlation between the dominant denitrifier ecotypes (nirS TRF 78, nosZ TRF 187) and soil pH. The representative sequences were identical to those of cultivated denitrifiers from acidic soils via phylogenetic tree analysis. Our results showed that the acidophilic denitrifier adaptation to the acid environment results in high N2O emission in this highly acidic tea soil.

Phosphorus removal and N2O production in anaerobic/anoxic denitrifying phosphorus removal process: long-term impact of influent phosphorus concentration.

This study was conducted to investigate the long-term impact of influent phosphorus concentration on denitrifying phosphorus removal and N2O production during denitrifying phosphorous removal process. The results showed that, denitrifying phosphate accumulating organisms (DPAOs) could become dominant populations quickly in anaerobic/anoxic SBR by providing optimum cultivating conditions, and the reactor performed well for denitrifying phosphorus removal. The influent phosphorus concentration significantly affected anaerobic poly-ß-hydroxyalkanoates (PHA) synthesis, denitrifying phosphorus removal, and N2O production during the denitrifying phosphorus removal process. As the influent phosphorus concentration was more than 20 mg L(-1), the activity of DPAOs began to be inhibited due to the transformation of the available carbon source type. Meanwhile, N2O production was inhibited with the mitigation of anoxic NO2(-)-N accumulation. Adoption of a modified feeding could enhance denitrifying phosphorus removal and inhibit N2O production during denitrifying phosphorous removal processes.