Intensification of phenol biodegradation by humic substances

Phenol biodegradation was carried out in a batch system by the bacterial strain Cupriavidus metallidurans in the presence of potassium humate that was prepared by alkaline extraction from oxyhumolite. The experiments were focused on the assessment of the humate effect on biodegradation activity of the tested bacterial strain. The achieved results demonstrated that the humate has a positive influence on the biodegradation of phenol and reduces the incubation time necessary for phenol removal. Higher biodegradation rate and more intensive growth were observed during the cultivation in presence of humate in comparison to the cultivation without its addition. Adsorption of the humate on bacterial biomass was observed as well. Subsequently, a phenol biodegradation testing in a continuous-flow system using a biofilm reactor was also carried out. Although the reactor was inoculated by C. metallidurans only, the microbial composition under an aerobic non-aseptic condition during this long-term cultivation changed. The phenol removal efficiency obtained in the biofilm reactor was higher than 92% when phenol concentration in a treated medium was 1200 mg l⁻¹.     

The gene-protective effect of sodium humate under conditions of induced oxidative stress

It was shown that sodium humate decreased the level of the dioxidin-induced clastogenic effects in the range of concentrations of 50 to 1000 mg/l; dioxidin, a mutagen with prooxidant properties, was used at the concentration of 20 mg/l. The maximum effect was observed at the concentration of 300 mg/l. No direct dose-response dependence under the effect of sodium humate was found. The feasible antioxidant and desmutagenic mechanisms of a protective effect of sodium humate are discussed.     

Effects of Humate, Agar-agar, and EDTA on the Development of Tomato Seedlings in Aerated and Non-aerated Water Cultures

The effect of sodium humate on the development of tomato seedlingsin aerated and non-aerated water cultures has been comparedwith the effect of colloidal solutions of agar-agar. Similarcomparisons have been made between the activities of humateand EDTA. The experiments have been conducted in fresh mediaas well as in nutrient solutions that had been formerly usedfor growing other tomato seedlings. Finally, a comparison betweeneffects of humate and EDTA on tomato seedlings growing in nutrientsolutions with various concentrations of calcium, magnesium,and iron salts in aerated and non-aerated water cultures hasbeen carried out. Media used for growth experiments have beentested microbiologically, and qualitative analyses of theirorganic compounds have been made. A distinct relationship between physiological activities ofhumate, EDTA, and the concentrations of calcium, magnesium,and iron cations in the medium has been found. It has also beenshown that in non-aerated media the plants mostly anifer thedeficiency of available iron; this is prevented by the additionof either humate or EDTA.     

Inducible catalase in Pseudomonas fluorescens

The catalase activity of a non-proliferating suspension of Pseudomonas fluorescens doubled after six hours incubation in a 50 mM phosphate buffer medium (pH 7.3). The same effect was observed in a peptone medium. The increased activity was due to induced enzyme synthesis, and not to activation of preexisting catalase. Induced catalase was separated by electrophoresis from deuterium labelled constitutive catalase. The enzyme was also induced under anaerobic conditions in phosphate buffer or in culture when nitrate was supplied as an electron acceptor. Induction was considerably increased by the addition of various nucleotides and amino acids to the incubation medium.     

Influence of sodium humate on the crop plants inoculated with bacteria of agricultural importance

Summary The dry-matter yield and nitrogen uptake of berseem (Trifolium alexand-drinum), yield, nitrogen uptake, nodulation and leghaemoglobin content of dhaincha (Sesbania aculeata) inoculated with specific rhizobia were appreciably influenced by the application of sodium humate to soil under green house conditions. Even the application of sodium humate alone without bacterial inoculation had good growth stimulating influence on both the crops, and this effect was further improved by the application of inorganic nitrogen to dhaincha plants. A fair increase in the yield and phosphorus up-take of wheat (Triticum vulgare) inoculated withAzotobacter and/orBacillus spp. was also recorded with the addition of the humic material to the soil. The greatest effect was observed on the plants inoculated withAzotobacter andBacillus spp. together.     

Phytoprotective Effect of Ammonium Humate at High Copper Concentrations in the Environment

The influence of ammonium humate obtained from peat on the tolerance of wheat plants to high CuSO₄ concentrations (100, 250, 500, and 1000 μM/L) has been studied. Seeds were germinated on a copper sulfate solution with and without the humate. Then the plants were grown on Hoagland’s solution in an artificial climate chamber. The coefficient of protective action by humate was estimated in the following two ways: by dry weight changes and by the copper ion content in comparison with the plants grown without humate. The protective role of the humate at 100 and 250 μM has been established, which is due to reduction of copper accumulation in the plants. It has been found that the humate at higher concentrations enhances the toxic effect of copper.     

A new dynamic model system for the study of capture reactions for diffusable compounds in cytochemistry. III. Influence of the matrix composition on the lead phosphate precipitation process in acid phosphatase cytochemistry

Synopsis A model system for the study of the dynamics of precipitation processes, described elsewhere and consisting of polyacrylamide films, was used to investigate the influence of the composition of the matrix, in which precipitation occurs, on the lead phosphate precipitation process in acid phosphatase cytochemistry. The situation at an enzymatic site can be simulated by pumping a phosphate-containing solution and the Gomori medium for acid phosphatase (lead containing medium) along opposite sides of a polyacrylamide film. The procipitation of lead phosphate was found to start at a lower phosphate concentration of the solution flowing along films into which histone, casein, RNA or polygalacturonate had been incorporated, than in control films. DNA, chondroitin sulphate and bovine serum albumin (unfixed) did not give this effect. Fixed bovine serum albumin incorporated into the film slightly decreased the phosphate concentration at which a precipitate appeared. Nuclear staining occurring under suboptimal conditions for phosphate trapping is probably due to a local matrix effect. The model studies suggested DNA-associated phosphorylated histones and phosphoproteins as likely candidates for such an effect, and RNA as a less likely one. Artefactual precipitates at the plasma membrane might be due to carboxyl groups of sialic acid.     

Phosphate dilution lowers net phosphatidyl choline synthesis in lymphocytes

The rate of net phosphatidyl choline (PC) synthesis in lymphocytes was evaluated, under appropriate conditions, in terms of [32P]phosphate incorporation. Phosphate-diluted and normal media were compared, with the cells being stimulated by concanavalin A or not. In either case, incubation in phosphate-diluted medium lowered net PC synthesis. In concanavalin A-stimulated cells, phosphate dilution also abolished the stimulation effect on net PC synthesis in G1. Nevertheless, these changes did not inhibit blastogenic transformation of cells.     

Neuronal Glutamine Utilization: Glutamine/Glutamate Homeostasis in Synaptosomes

The synaptosomal metabolism of glutamine was studied under in vitro conditions that simulate depolarization in vivo. With [2-15N]glutamine as precursor, the [glutamine]i was diminished in the presence of veratridine or 50 mM KCl, but the total amounts of [15N]glutamate and [15N]aspartate formed were either equal to those of control incubations (veratridine) or higher (50 mM [KCl]). This suggests that depolarization decreases glutamine uptake and independently augments glutaminase activity. Omission of sodium from the medium was associated with low internal levels of glutamine which indicates that influx occurs as a charged Na(+)-amino acid complex. It is postulated that a reduction in membrane potential and a collapse of the Na+ gradient decrease the driving forces for glutamine accumulation and thus inhibit its uptake and enhance its release under depolarizing conditions. Inorganic phosphate stimulated glutaminase activity, particularly in the presence of calcium. At 2 mM or lower [phosphate] in the medium, calcium inhibited glutamine utilization and the production of glutamate, aspartate, and ammonia from glutamine. At a high (10 mM) medium [phosphate], calcium stimulated glutamine catabolism. It is suggested that a veratridine-induced increase in intrasynaptosomal inorganic phosphate is responsible for the enhancement of flux through glutaminase; calcium affects glutaminase indirectly by modulating the level of free intramitochondrial [phosphate]. Because phosphate also lowers the Km of glutaminase for glutamine, augmentation of the amino acid breakdown may occur even when depolarization lowers [glutamine]i. Reducing the intrasynaptosomal glutamate to 26 nmol/mg of protein had little effect on glutamine catabolism, but raising the pH to 7.9 markedly increased formation of glutamate and aspartate. It is concluded that phosphate and H+ are the major physiologic regulators of glutaminase activity.     

Influence of medium composition on sporulation byStreptomyces coelicolor A3(2) grown on defined solid media

Summary Reproducible sporulation using solid-plate cultures ofStreptomyces coelicolor A3(2) was obtained on a defined medium with glucose as the primary source of carbon and sodium nitrate as the sole source of nitrogen. The type of agar used as a solidifying agent, and the inclusion of trace salts to the medium, significantly affected sporulation. An interrelationship between the medium carbon to nitrogen ratio and sporulation was observed, with clear promotion of spore formation under nitrogen-limited conditions, whilst carbon-limited conditions suppressed sporulation. The influence of medium phosphate upon sporulation is also reported, with high concentrations exerting an inhibitory effect.     

Production of citric and oxalic acids and solubilization of calcium phosphate by Penicillium bilaii.

An isolate of Penicillium bilaii previously reported to solubilize mineral phosphates and enhance plant uptake of phosphate was studied. Using agar media with calcium phosphate and the pH indicator alizarin red S, the influence of the medium composition on phosphate solubility and medium acidification was recorded. The major acidic metabolites produced by P. bilaii in a sucrose nitrate liquid medium were found to be oxalic acid and citric acid. Citric acid production was promoted under nitrogen-limited conditions, while oxalic acid production was promoted under carbon-limited conditions. Citric acid was produced in both growth and stationary phases, but oxalic acid production occurred only in stationary phase. When submerged cultures which normally produce acid were induced to sporulate, the culture medium shifted toward alkaline rather than acid reaction with growth.     

Production of citric and oxalic acids and solubilization of calcium phosphate by Penicillium bilaii.

An isolate of Penicillium bilaii previously reported to solubilize mineral phosphates and enhance plant uptake of phosphate was studied. Using agar media with calcium phosphate and the pH indicator alizarin red S, the influence of the medium composition on phosphate solubility and medium acidification was recorded. The major acidic metabolites produced by P. bilaii in a sucrose nitrate liquid medium were found to be oxalic acid and citric acid. Citric acid production was promoted under nitrogen-limited conditions, while oxalic acid production was promoted under carbon-limited conditions. Citric acid was produced in both growth and stationary phases, but oxalic acid production occurred only in stationary phase. When submerged cultures which normally produce acid were induced to sporulate, the culture medium shifted toward alkaline rather than acid reaction with growth.     

The effect of humic acid on transamination in winter wheat plants

A very low, for the most part unmeasurable glutamic-aspartio transminase activity and a very high glutamic-alanine transaminase activity was found in the overground parts and roots of young wheat plants. The roots had a higher glutamic-alanine transaminase activity than the overground parts in the first and second leaf stage. Plants cultivated in Knop’s nutrient solution (variant with humate and without) showed a higher glutamic-alanine transaminase activity than poorly growing plants, cultivated in distilled water (with humate and without). In plants cultivated in nutrient solutions, transaminase activity increased with the age of the wheat plants. As in the previous experiments, the effect of humate was only significant, in the roots of plants cultivated in distilled water with humate, where transamination activity was greater than in the control without humate. The roots of this variant with a stimulatory growth effect showed a large accumulation of free sugars in the previous experiments. The connection between these effects of humate on the roots of young winter wheat plants is discussed.     

Influence of Phosphate on the Growth and Nodulation Characteristics of Rhizobium trifolii

The growth and nodulating characteristics of Rhizobium trifolii 6 and 36 differed under different external phosphate conditions. Under growth conditions designed to deplete the internal phosphate content of the rhizobia, strain 6 maintained a generation time of 5 h during the exponential phase over two cycles of growth in phosphate-depleted medium. In contrast, the generation time of strain 36 was extended from 3.5 to 9.8 h over two cycles of phosphate-depleted growth, although the organism eventually achieved the same cell density and cellular phosphate content as that of strain 6 at stationary phase. Phosphate-depleted strain 6 required 0.51 ± 0.08 μM phosphate to commence proliferation, whereas phosphate-depleted strain 36 required 0.89 ± 0.04 μM phosphate under the same conditions. Phosphate-depleted strain 6 maintained viability when exposed to external phosphate concentrations subcritical for growth to occur, whereas phosphate-depleted strain 36 lost viability within 48 h when exposed to medium containing phosphate at concentrations subcritical for growth. Phosphate-depleted strain 36 was inferior to phosphate-depleted strain 6 at nodulating subterranean clover (Trifolium subterraneum L. cv. Mt. Barker) by taking 2 to 4 days longer to develop nodules in phosphatedepleted plant grown medium at pH 5.5. Nodulation by phosphate-depleted strain 36 was accelerated either by including phosphate in the plant growth medium at pH 5.5 or by raising the solution pH of phosphate-depleted plant growth medium to pH 6.5. External phosphate and pH effects were not observed on the nodulating capabilities of phosphate-depleted strain 6 or on luxury phosphate-grown cells of either strain. Phosphatedepleted strains 6 and 36 proliferated to a similar extent on the rhizoplanes even under stringently low external P_i concentrations. The phosphatase activities of both phosphate-depleted strains were significantly (P = 0.05) higher at pH 6.5 than at pH 5.5, and the activity of strain 6 was significantly higher (P = 0.05) than that of strain 36 at pH 5.5 and 5.0.     

Effect of trophic conditions and humic acid on alanine transamination in wheat plants

In dialyzed extracts from winter wheat plants an intensive enzymatical transamination reaction occurred between L-α-alanine and α-ketoglutaric acid (L-α-alanine + + 2-oxoglutarate = pyruvate + L-glutamate, EC 2.6.1.2) as well as a weak nonenzymatical transamination reaction, practically immeasurable. Pyridoxal-5’-phosphate strongly affected the reaction rate. Besides the transamination product-glutamate, γ-aminobutyric acid was formed in this reaction. This amino acid could have originated neither via proteolysis of the enzyme extract, nor via decarboxylation from glutamate formed, nor via transamination of succinic-γ-semialdehyde after α-ketoglutarate decarboxylation. This was the only case of its formation in the transamination reactions investigated in our laboratory — it originated from the alanine-glutamate reaction only, and the mechanism of its biosynthesis cannot be elucidated for the present. Dialysates from shoots exhibited a significantly higher enzymatic activity in comparison with those from roots. The effect of trophic conditions (Knop’s nutrient solution, a water solution of potassium humate, water) was not revealed when calculating per dry weight unit. However, when calculating per protein unit an increased activity was found in the dialysates from shoots of both nutrient — deficient variants. Roots of plants cultivated in potassium humate had the lowest activity. The discussion concerns the possibility of an adaptive use of this transamination for increasing the essential glutamate level in green parts of the plants cultivated under unfavourable nutritive conditions, and also deals with a further characteristic of the differing metabolism of plants cultivated in humate.     

Pseudomonas corrugata (NRRL B-30409) Mutants Increased Phosphate Solubilization, Organic Acid Production, and Plant Growth at Lower Temperatures

A study for screening and selection of mutants of Pseudomonas corrugata (NRRL B-30409) based on their phosphate solubilization ability, production of organic acids, and subsequent effect on plant growth at lower temperatures under in vitro and in situ conditions was conducted. Of a total 115 mutants tested, two (PCM-56 and PCM-82) were selected based on their greater phosphate solubilization ability at 21°C in Pikovskaya’s broth. The two mutants were found more efficient than wild-type strain for phosphate solubilization activity across a range of temperature from psychotropic (4°C) to mesophilic (28°C) in aerated GPS medium containing insoluble rock phosphate. High-performance liquid chromatography analysis showed that phosphate solubilization potential of wild-type and mutant strains were mediated by production of organic acids in the culture medium. The two efficient mutants and the wild strain oxidized glucose to gluconic acid and sequentially to 2-ketogluconic acid. Under in vitro conditions at 10°C, the mutants exhibited increased plant growth as compared to wild type, indicating their functionality at lower temperatures. In greenhouse trials using sterilized soil amended with either soluble or rock phosphate, inoculation with mutants showed greater positive effect on all of the growth parameters and soil enzymatic activities. To the best of our knowledge, this is the first report on the development of phosphate solubilizing mutants of psychotropic wild strain of P. corrugata, native to the Indian Himalayan region.     

Characteristics of the intensity of glycolytic and oxidative processes in rat brain tissue under hypoxia and hyperoxia

Effect of hypoxia and hyperoxia on some indexes of energy metabolism was studied in the brain of intact rats and those with preliminarily administered hydrocortisone. So hypoxia (8 and 5.5% of oxygen in the medium) increases considerably the lactate and pyruvate content and has no effect on the oxidation and photophosphorylation in the brain mitochondria. The hyperoxic medium (1 at. abs. for 3-5h) inhibits consumption of oxygen and inorganic phosphate by the brain mitochondria, does not effect the lactate content and lowers the pyruvate level. The preliminary administration of hydrocortisone (1 mg per 100 g) under conditions of hypoxia and hyperoxia leads to the further intensification of the glycolysis independently of the initial level of the process. At the same time hormone administration favours normalization of the oxidative processes in the brain tissue under conditions of hyperoxia.     

Quantitative short-term uptake of inorganic phosphate by the Chara hispida rhizoid

Abstract The rhizoid of Chara hispida L. made a small contribution to the uptake of inorganic phosphate under laboratory conditions. At 1 mmol m^?3 phosphate the rhizoid contributed about 4% to the uptake of the whole plant over 4 h. Under these conditions about half of the phosphate taken up by the rhizoid was translocated into the shoot. The rates of uptake and translocation increased with increasing external phosphate concentrations. When the shoot was in darkness, ³²P-translocation from the rhizoid was less than half of that found when the shoot was illuminated. When the rhizoid medium was anaerobic the translocation rate was lower than the rate in aerobic conditions and illumination of the shoot had no effect on the uptake or translocation of phosphate. Translocated ³²P accumulated in the apical growing regions of the plant. This was first noted in the secondary apices nearest to the rhizoids.     

Effect of a formulation of urea,thiourea and humate on nitrogen availability and yield of wheat

Summary Urea was mineralized completely in 15 days when applied at concentrations of 50 and 30 ppm nitrogen (N) in the soil. Humate showed no effect whereas thiourea with and without humate delayed nitrate formation by 30 days.In pot-culture experiment, humate at 1.0 ppm concentration increased the grain yield of wheat but not significantly. Urea (25 ppm N) and thiourea (5 ppm N) increased the grain yield significantly. This effect was stimulated by humate treatment. re]19760629     

响应面设计法优化单葡萄糖醛酸基甘草次酸（GAMG）发酵转化培养基

以甘草酸（dycyfrhizin,GL）为底物,利用产紫青霉（Penicillium purpurogenum Li-3）液态发酵转化单葡萄糖醛酸甘草次酸（GAMG）,采用响应面设计法对初始发酵培养基进行优化。用部分因子分析法研究原始发酵培养基各成分对响应值的显著程度,发现甘草酸（GL）、NaNO3和K2HPO4的质量浓度对发酵产生GAMG的影响显著（P〈0．01）。用中心组合设计确立甘草酸、NaNO3和K2HPO4的适宜质量浓度分别为2．8、3．0和0．8g／L。在优化条件下进行发酵时,GAMG的转化率从75．49％提高到89．11％,比优化前提高了13．62％。