Anaerobic degradation of phenanthrene by a newly isolated humus-reducing bacterium, <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> strain PAH-1

Purpose  

The anaerobic degradation of polycyclic aromatic hydrocarbons (PAHs) has great significance to PAHs’ natural attenuation in contaminated sites. Previous studies mainly focused on anaerobic PAH degradation by mixed cultures with nitrate, sulfate, or Fe(III) oxides as electron acceptors, and the roles of pure cultures in the process was rarely reported. The aim of this paper is to isolate a pure culture that is capable of degrading phenanthrene anaerobically with anthraquinone-2,6-disulphonate (AQDS) as the sole electron acceptor and evaluate its environmental functions.     

Characteristics of an amidase isolated from a soil bacterium

Amidase was extracted from a bacterium isolated from soil, and its properties were compared with those of amidase in soil. Amidase activity of the bacterial protein was lower than that of soil amidase, respectively, in its optimal pH (7.0 vs 8.5), optimal temperature (50 vs 60°C), K_m constant calculated by the Lineweaver-Burk plot (5.6 vs 17.9 mm), activation energy (18.9 vs 43.3 kJmol^?) and Q₁₀ (av. = 1.28 vs 1.75). Bacterial amidase was stable at temperatures ranging from 10 to 50°C and denatured at 55°C. Toluene inhibited both bacterial and soil amidase.When the inhibitions by 21 trace elements were compared by using 2 μmol 0.1 mg^?1 protein, the most effective inhibitors of bacterial amidase (> 25% inhibition) were: Ag(I), Cd(II), Cu(II), Hg(II), Ni(II), Pb(II), Zn(II), Al(III) and Se(IV). The effect of 16 pesticides on bacterial amidase varied considerably. By using 2 μg of active ingredient of pesticide 0.1 mg^?1 protein, the inhibition of bacterial amidase ranged from 7 to 49% with Dinitroamine and Butylate, respectively. The results show that soil constituents have a considerable influence on the reaction catalyzed by this enzyme.     

Fe(II) oxidation and nitrate reduction by a denitrifying bacterium,Pseudomonas stutzeri LS-2, isolated from paddy soil

Journal of Soils and Sediments - Ferrous iron (Fe(II)) oxidation and nitrate (NO3 ?) reduction are commonly observed in environments with denitrifying bacteria. The intermediate nitrite (NO2...     

Antidiabetic activities of chalcones isolated from a Japanese Herb, Angelica keiskei

Diabetes mellitus is a chronic disease that is characterized by hyperglycemia caused by insufficient insulin action. We have explored the edible ingredients from folk medicines in Japan that contain substances complementing insulin action, such as the induction of adipocyte differentiation and the enhancement of glucose uptake. We eventually found that the ethanol extract from a Japanese herb "Ashitaba", Angelica keiskei, contained two major chalcones of 4-hydroxyderricin (4-HD) and xanthoangelol that showed strong insulin-like activities via a pathway independent of the peroxisome proliferator-activated receptor-gamma activation. The 4-HD especially showed the preventive effects on the progression of diabetes in genetically diabetic KK-Ay mice.     

Nitrogen mineralization from digestate in comparison to sewage sludge,compost and urea in a laboratory incubated soil experiment

This paper evaluated, in a laboratory incubated soil, the properties of digestate as a nitrogen fertilizer in comparison with sewage sludge, compost and urea, this last as a typical mineral fertilizer. The incubation period lasted for 90 d and during this time, pH, CO₂ and evolution were measured. The maximum concentration of nitrate was reached in the incubated microcosm fertilized by urea (133 mg kg⁻¹ after 62 d), and that of digestate was very similar (113 mg kg⁻¹). Soil treated with compost showed a slower nitrate evolution. A significantly negative correlation was detected between cumulative nitrogen nitrified at the end of the trial, and the values of the C:N ratio of the biomasses used (compost, sludge and digestate) (mg kg⁻¹ vs . C:N, r = –0.94, n = 3, p < 0.05), and between the alkyl‐C content at the end of the experiment (mg kg⁻¹ vs . alkyl‐C, r = –0.95, n = 3, p < 0.05). As expected, pH decreases and soil respiration (CO₂ evolution) were also well correlated with the content of nitrate. Considering that about 90% of the nitrogen content in the digestate is short acting, the results obtained indicate that the nitrogen rate of mineralization in digestate is very similar to that of urea, confirming that digestate could replace traditional mineral fertilizers.     

Propolin G, a prenylflavanone, isolated from Taiwanese propolis, induces caspase-dependent apoptosis in brain cancer cells

We have previously shown that six propolins, A-F, could be isolated from Taiwanese propolis (TP) and that they exerted a broad spectrum of biological activities. Recently, we isolated a seventh compound, propolin G. Its chemical structure has been identified by NMR and fast atom bombardment-mass spectrometry spectra and was found to be identical to a known compound, nymphaeol C. We used high-performance liquid chromatography to determine the relative contents of propolins C, D, F, and G in TP collected in various seasons and regions and found them to be relatively higher in TPs collected from May to July than from September to October. In our present study, we were interested in the various biological activities of TP extract as well as in propolin G as a pure compound. We found that propolin G could efficiently induce apoptosis in brain cancer cell lines (glioma and glioblastoma). The apoptosis might have been through a mitochondrial- and caspase-dependent pathway. This result demonstrated that the TP collection season was more an important factor than the geographical region. Propolis has been suggested to possess a potent antioxidant activity. We further evaluated the antioxidant property of propolin G using DPPH (1,2-diphenyl-2-picryhydrazyl). Our results indicate that propolin G does possess free radical scavenging activity. We also evaluated the neuroprotective action of propolin G, TP, and BP (Brazilian propolis) extracts against oxidative stress in rat primary cortical neurons. Our data demonstrate that propolin G and TP extracts have a marked neuroprotective effect that is greater than BP extract. In conclusion, the isolation and characterization of propolin G from TP have demonstrated for the first time that this compound is a potent inducer of apoptosis in brain cancer cells and that this compound and TP extract exhibit a protective effect against oxidative stress in rat cortical neurons.     

Antimutagenicity of some edible Thai plants,and a bioactive carbazole alkaloid,mahanine, isolated from Micromelum minutum

The antimutagenic activity against Trp-P-1 of methanolic extracts of 118 samples (108 species) of edible Thai plants was examined by the Ames Test. The activity was evaluated by the amount of plant extracts which suppressed 90% of the mutagenesis (ED90). Five plants, Micromelum minutum, Oroxylum indicum, Cuscuta chinensis, Azadirachta indica, and Litsea petiolata, exhibited significant activity with antimutagenic ED90 values lower than 5 microL/plate (0.1 mg of dry plant material equivalent). The activity-guided fractionation of the extract of M. minutum, which exhibited the highest antimutagenic activity in the screening, resulted in the isolation of an active principle, (+)-mahanine (1) as confirmed by its physicochemical properties. Compound 1 showed a wide variety of biological activity, including antimutagenicity against heterocyclic amines such as Trp-P-1 with an IC50 of 5.2 microM, cytotoxicity against a tumor cell line HL60 with a MIC100 of 4.0 microg/mL, and antimicrobial activity against Bacillus cereus and Staphylococcus aureus with MIC100 values of 6.25 and 12.5 microg/mL, respectively.     

Antifungal synergistic effect of scopoletin, a hydroxycoumarin isolated from Melia azedarach L. fruits

In the continuous search for antifungal compounds from plants, the hydroxycoumarin scopoletin (1) was isolated from seed kernels of Melia azedarach L. from which three other compounds, vanillin (2), 4-hydroxy-3-methoxycinnamaldehyde (3), and (+/-) pinoresinol (4), have also been isolated. Guided fractionation through autobiography on TLC using Fusarium verticillioides (Saccardo) Nirenberg as test organism led to the isolation of 1, which exhibited a minimum inhibitory concentration (MIC) of 1.50 mg/mL in the microbroth dilution method. Despite its own weak activity, when the coumarin was combined with the above-mentioned compounds, a strong enhancement of the antifungal effect was observed, even showing a complete inhibition in the growth of the pathogen when 1 was added at a concentration of up to 5% of its MIC value. The same level of effectiveness was observed when the synthetic antifungal agents Mancozeb and Carboxin were each combined with compounds 1-4, in which cases it became possible to decrease the effective concentrations of these commercial compounds by up to 2.5 and 3%, respectively.     

Insecticidal activity of penitrems,including penitrem G,a new member of the family isolated from Penicillium crustosum

Penitrem G (7), a new indole-diterpenoid compound, has been isolated together with the already known mycotoxins penitrems A-D (1-4) and F (6) from the mycelium of Penicillium crustosum Thom. The structure of penitrem G was established on the basis of spectroscopic data. In addition, paspaline (8), another indole-diterpenoid mycotoxin that has not been previously described in this fungus, was also isolated. These compounds were tested for insecticidal activity against the hemipteran Oncopeltus fasciatus Dallas and the dipteran Ceratitis capitata Wiedemann. Penitrems A-D and F showed convulsive and insecticidal activities against both insect species. In addition, important reductions in the fecundity and fertility of the surviving C. capitata females were observed. In contrast, penitrem G and paspaline did not show any kind of activity. Mortality data and sublethal effects of the treatments have allowed preliminary structure-activity relationships to be proposed.     

2-O-(beta-D-Glucopyranosyl)ascorbic acid, a novel ascorbic acid analogue isolated from Lycium fruit

A novel stable precursor of ascorbic acid (vitamin C), 2-O-(beta-D-glucopyranosyl)ascorbic acid, was isolated from both the ripe fresh fruit and dried fruit of Lycium barbarum L., a plant of the Solanaceae family. The chemical structure was inferred by instrumental analyses and confirmed by chemical synthesis. The dried fruit of Lycium barbarum L. contained ca. 0.5% of it, which is comparable to the ascorbic acid content of fresh lemons. It increased the blood ascorbic acid by oral administration to rats, and it was also detected in blood from the portal vein.     

Terpendole M, a novel indole-diterpenoid isolated from Lolium perenne infected with the endophytic fungus Neotyphodium lolii.

Terpendole M (1), a novel indole-diterpenoid, was isolated from perennial ryegrass (Lolium perenne) infected with the endophytic fungus Neotyphodium lolii. It was identified as 14alpha-hydroxyterpendole C by NMR and mass spectral techniques. The known indole-diterpenoids paspaline (3) and 13-desoxypaxilline (4) were also isolated from perennial ryegrass for the first time. Terpendole M was less tremorgenic than terpendole C (2) in a standard mouse bioassay. These findings provide clues to the biogenesis of the lolitrem neurotoxins, and information on the structure-activity relationships within the indole-diterpenoids.     

Effects of preceding compost application on the nitrogen budget in an upland soybean field converted from a rice paddy field on gray lowland soil in Akita,Japan

Abstract

The annual nitrogen (N) budget was measured in a soybean-cultivated upland field during the first year after conversion from a paddy field on gray lowland soil, which is typically found on the Sea of Japan side of northern Japan. Forage rice was cultivated on lysimeter fields for 4 consecutive years with applications of chemical fertilizer, immature compost, or mature compost (the control, immature compost, and mature compost plots, respectively), and then the fields were converted to upland fields for soybean (Glycine max [L.] Merrill cultivar Ryuho) cultivation. Input (seed, bulk N deposition, and symbiotic dinitrogen [N₂] fixation) and output (harvested grain, leached N via drainage water, and nitrous oxide emission) N flows were measured, and the field N budget was estimated from the difference between the input and output. The soybean plants in the immature and mature compost plots grew well and had higher yields (498–511 g m)^?2) compared to the control plot (410 g m)^?2). Total N accumulation in the soybean plants derived from N₂ fixation (g N m)^?2) in the mature compost plot (27.7) was higher than those in the control (18.1) and immature compost plots (19.9). Percentages of soybean N accumulation derived from N₂ fixation ranged from 53% to 74%. N derived from symbiotic N₂ fixation accounted for more than 90% of the total N input, whereas harvested grain accounted for approximately 85% of the total N output. N leaching mainly occurred during the fallow period, accounting for 13–15% of the total N output. The annual N budgets were negative (?10.0,?14.2, and ?6.4 g N m)^?2 year)^?1 for the control, immature compost, andmature compost plots, respectively). The Nloss from the immature compost plot was higher than that of the control plot, because the N output in harvested grain was higher, and the N input by N₂ fixation was similar between plots. While the N loss from the mature compost plot was lower than that of the control plot because the N output in harvested grain was higher, as was the case in the immature compost plot, the N input by N₂ fixation was also higher. Preceding compost application—whether immature or mature compost—to paddy fields increased the subsequent soybean yield during the first year after conversion. This result suggests that N loss and the following decrease in soil N availability in the field could be mitigated by increased N₂ fixation resulting from mature compost application with an appropriate application practice.     

Effect of the long-term application of organic matter on soil carbon accumulation and GHG emissions from a rice paddy field in a cool-temperate region,Japan-II. Effect of different compost applications-

ABSTRACT

The influence of long-term application of different types of compost on rice grain yield, CH₄ and N₂O emissions, and soil carbon storage (0 ? 30 cm) in rice paddy fields was clarified. Two sets of paddy fields applied with rice straw compost or livestock manure compost mainly derived from cattle were used in this study. Each set comprised long-term application (LT) and corresponding control (CT) plots. The application rates for rice straw compost (42 years) and livestock manure compost (41 years in total with different application rates) were 20 Mg fresh weight ha^–1. Soil carbon storage increased by 33% and 37% with long-term application of rice straw compost and livestock manure compost, respectively. The soil carbon sequestration rate by the organic matter application was 23% higher with the livestock manure compost than with the rice straw compost. The rice grain yield in the LT plot was significantly higher than that in the corresponding CT plot with both types of compost. Although the difference was not significant in the rice straw compost, cumulative CH₄ emissions increased with long-term application of both composts. Increase rate of CH₄ emission with long-term application was higher in the livestock manure compost (99%) than that in the rice straw compost (26%). In both composts, the long-term application did not increase N₂O emission significantly. As with the rice straw compost, the increase in CH₄ emission with the long-term application of livestock manure compost exceeded the soil carbon sequestration rate, and the change in the net greenhouse gas (GHG) balance calculated by the difference between them was positive, indicating a net increase in the GHG emissions. The increase in CH₄ and net GHG emissions owing to the long-term application of the livestock manure compost could be higher than that of the rice straw compost owing to the amount of applied carbon, the quality of compost and the soil carbon accumulation. The possibility that carbon sequestration in the subsoil differs depending on the type of composts suggests the importance of including subsoil in the evaluation of soil carbon sequestration by long-term application of organic matter.     

Diplonine, a neurotoxin isolated from cultures of the fungus Stenocarpella maydis (Berk.) Sacc. that induces diplodiosis

Diplodiosis is a neuromycotoxicosis of cattle and sheep caused by ingestion of maize infected with the ear-rot fungus Stenocarpella (= Diplodia ) maydis . Apart from ataxia, paresis, and paralysis, the toxin is responsible for stillbirths and neonatal losses characterized by the presence of spongiform degeneration in the white matter of the brain in the offspring of dams exposed to infected maize cobs. In the present study a toxin, named diplonine, which induced neurological signs in guinea pigs resembling some of those occurring in cattle and sheep, was isolated from S. maydis cultures. Purification of diplonine was achieved by methanol extraction followed by chromatographic separation on silica gel and RP-18 stationary phases. The structure and relative configuration of diplonine were defined by analysis of NMR and MS data as (S)-2-amino-2-[(1R,2S)-1-hydroxy-2-methylcyclopropyl]acetic acid or the (S)-2-amino-2-[(1S,2R)-diastereomer.     

Effect of the long-term application of organic matter on soil carbon accumulation and GHG emissions from a rice paddy field in a cool-temperate region,Japan. -I. Comparison of rice straw and rice straw compost -

ABSTRACT

The influence of the long-term combination of rice straw removal and rice straw compost application on methane (CH₄) and nitrous oxide (N₂O) emissions and soil carbon accumulation in rice paddy fields was clarified. In each of the initial and continuous application fields (3 and 39?51 years, respectively), three plots with different applications of organic matter were established, namely, rice straw application (RS), rice straw compost application (SC) and no application (NA) plots, and soil carbon storage (0?15 cm), rice grain yield and CH₄ and N₂O fluxes were measured for three years. The soil carbon sequestration rate by the organic matter application was higher in the SC plot than in the RS plot for both the initial and continuous application fields, and it was lower in the continuous application field than in the initial application field. The rice grain yield in the SC plot was significantly higher than those in the other plots in both the initial and continuous application fields. Cumulative CH₄ emissions followed the order of the NA plot < the SC plot < the RS plot for both the initial and continuous application fields. The effect of the organic matter application on the N₂O emissions was not clear. In both the initial and continuous application fields, the increase in CH₄ emission by the rice straw application exceeded the soil carbon sequestration rate, and the change in the net greenhouse gas (GHG) balance calculated by the difference between them was a positive, indicating a net increase in the GHG emissions. However, the change in the GHG balance by the rice straw compost application showed negative (mitigating GHG emissions) for the initial application field, whereas it showed positive for the continuous application field. Although the mitigation effect on the GHG emissions by the combination of the rice straw removal and rice straw compost application was reduced by 21% after 39 years long-term application, it is suggested that the combination treatment is a sustainable management that can mitigate GHG emissions and improve crop productivity.     

Heterotrophic nitrification and nitrite tolerance by aspergillus carneus (van tiegh) blochwitz,a predominant fungus isolated from benomyl-amended soil

Nitrogen transformations by Aspergillus carneus (van Tiegh) Blochwitz, a predominant fungus isolated from benomyl-amended soil was studied. The organism oxidized NH⁺₄ to NO^?₂; NO^?₃ was not detected. NO^?₂ was also produced from peptone in a sterilized soil inoculated with A. carneus. The fungus tolerated 10³ parts/10⁶ NaNO₂. Complete disappearance of NO^?₂ occurred from media amended with 500 parts/10⁶ NaNO₂ in 24 days. The fungus also reduced NO^?₃ to NO^?₂.