外源酚对凤眼莲体内酚含量和与酚代谢有关酶的影响

凤眼莲能够吸收和在体内聚集外源苯酚,体内的酸含量随着环境中酚浓度的上升而上升。从生长于合酚培养液中的凤眼莲体内能够检测到酚糖苷,说明凤眼莲体内有酚精苷转移酶的存在。浓度小于５０ｍｇ／Ｌ的外源酚能提高凤眼莲体内的多酚氧化酶和过氧化物酶的活性。多酚氯化酶与过氧化物酶在线粒体和微粒体中均有不同程度的分布,而酚糖苷转移酶则不存在于这些细胞器中。     

A specific method for the determination of soluble sugars in plant extracts using enzymatic analysis and its application to the sugar content of developing pear fruit buds

A simple manual method for the routine analysis of glucose, fructose, mannose, galactose, and sucrose in plant material is described. The technique is demonstrated using various seeds known to form part of the diet of the bullfinch (Pyrrhula pyrrhula L.), a pest of commercial orchards in southeast England. The method involves the overnight extraction of the sugars with 62.5% aqueous methanol, followed by the conversion of the individual sugars to gluconate 6-phosphate (or, in the case of galactose, to galactono-gamma-lactone) by specific enzymes, and their determination spectrophotometrically.     

Role of Sugars and Phenols in Charcoalrot Resistance of Sorghum

Total sugars, reducing sugars, and phenols were estimated in internodes of tolerant and highly susceptible sovhum genotypes to charcoal, ln tolerant genotypes the sugar level was 2 to 3 times higher than in susceptible ones; phenol concentration also was higher in tolerant genotypes. In tolerant genotypes, sugar and phenol concentration was high in the lower most and in the upper most mternode. This may be used to identify sources of resistance.     

低温高效苯酚降解菌的分离与降解特性

从哈尔滨太平污水厂活性污泥中筛选到7株高效苯酚降解菌,可利用苯酚作为唯一碳源和能源。通过对这7株菌在不同温度、pH值、以及不同苯酚浓度下生长和苯酚降解情况的考察,确定了这7株菌的最适生长温度为10°C,最适pH值为7.5,最大可降解苯酚浓度为3000mg/L。通过对这7株苯酚降解菌降解性能的研究表明:其具有较强的苯酚降解能力,在10°C、pH值为7.5、装液量为50mL、接种量15%、摇床振荡速度160r/min的条件下,反应48h后可使500mg/L的苯酚降解率达90%以上。葡萄糖对菌体的生长及苯酚降解能力均有一定的影响,当葡萄糖浓度是500mg/L时,该菌对苯酚的降解率仍在80%以上。该研究对处理含有其它碳源的含酚废水具有一定的意义。通过DGGE图谱条带的分析表明,其亮度可以说明这些菌在各个系统中均表现为优势菌,且在污水环境中表现出较强的活性,其优势地位能够稳定地存在。其中2、4、24、28条带丰富,表现出它们在污水环境系统中的多样性。     

Capillary electrophoresis for the determination of major amino acids and sugars in foliage: application to the nitrogen nutrition of Sclerophyllous species

Amino acids and sugars are probably the most commonly measured solutes in plant fluids and tissue extracts. Chromatographic techniques used for the measurement of such solutes require complex derivatization procedures, analysis times are long and separate analyses are required for sugars and amino acids. Two methods were developed for the analysis of underivatized sugars and amino acids by capillary electrophoresis (CE). Separation of a range of sugars and amino acids was achieved in under 30 min, with good reproducibility and linearity. In general, there was close agreement between amino acid analyses by CE and HPLC with post-column derivatization. An alternative, more rapid method was optimized for the common neutral sugars. Separation of a mixture of fructose, glucose, sucrose, and fucose (internal standard) was achieved in less than 5 min. How the source of N applied (nitrate or ammonium) and its concentration (8.0 or 0.5 mM) affects the amino acid and sugar composition of leaves from Banksia grandis Willd. and Hakea prostrata R. Br. was investigated. The amino acid pool of Banksia and Hakea were dominated by seven amino acids (aspartic acid, glutamic acid, asparagine, glutamine, serine, proline, and arginine). Of these, asparagaine and glutamine dominated at low N-supply, whereas at high N-supply the concentration of arginine increased and dominated amino-N. Plants grown with nitrate had a greater concentration of proline relative to plants with ammonium. In Banksia the concentration of amides was greatest and arginine least with a nitrate N-source, whereas in Hakea amides were least and arginine greatest with nitrate N-source. The concentration of sugars was greater in Banksia than Hakea and in both species at greater N-supply.     

一株苯酚降解菌的鉴定及其降解特性

【目的】鉴定从某化工厂附近土样中分离到的一株耐高浓度苯酚的菌株T10,通过优化菌株的培养条件提高菌株对苯酚的降解率。【方法】根据菌株的形态、生理生化鉴定及16S rDNA测序分析确定其种属,以液体摇瓶培养菌株T10对苯酚的降解率为指标,对菌株的生长条件进行优化。【结果】菌株T10属恶臭假单胞菌(Pseudomonas putida)。添加葡萄糖、蛋白胨能有效缩短T10菌的生长周期,并使苯酚的降解率提高1.7倍。在菌体初始接种浓度为10%、温度为30°C、转速为180 r/min条件下,对初始苯酚浓度、pH和装液量的响应面优化结果如下:初始苯酚浓度3 000 mg/L、pH 7.5和装液量80 mL/250 mL,苯酚去除率最高可达到87.56%。【结论】T10菌能够耐受较高浓度的含酚废水,并且对苯酚有较强的降解能力,为下一步利用生物法处理含酚废水提供科学依据。     

Analysis of plant nucleotide sugars by hydrophilic interaction liquid chromatography and tandem mass spectrometry

Understanding the intricate metabolic processes involved in plant cell wall biosynthesis is limited by difficulties in performing sensitive quantification of many involved compounds. Hydrophilic interaction liquid chromatography is a useful technique for the analysis of hydrophilic metabolites from complex biological extracts and forms the basis of this method to quantify plant cell wall precursors. A zwitterionic silica-based stationary phase has been used to separate hydrophilic nucleotide sugars involved in cell wall biosynthesis from milligram amounts of leaf tissue. A tandem mass spectrometry operating in selected reaction monitoring mode was used to quantify nucleotide sugars. This method was highly repeatable and quantified 12 nucleotide sugars at low femtomole quantities, with linear responses up to four orders of magnitude to several 100 pmol. The method was also successfully applied to the analysis of purified leaf extracts from two model plant species with variations in their cell wall sugar compositions and indicated significant differences in the levels of 6 out of 12 nucleotide sugars. The plant nucleotide sugar extraction procedure was demonstrated to have good recovery rates with minimal matrix effects. The approach results in a significant improvement in sensitivity when applied to plant samples over currently employed techniques.     

Simultaneous Measurement of the Galacturonate and Neutral Sugar Contents of Pectic Substances by an Enzymic-HPLC Method

An enzymic-HPLC method was successfully applied to the simultaneous analysis of the galacturonate and neutral sugar contents of pectic substances. A mixture of seven neutral sugars that are present in oridnary pectins was eluted as one peak on a Shodex SUGAR SH1821 column, using 0.001 N sulfuric acid as the eluent; the peak was completely separated from that of galacturonate. No difference in the peak-area ratios of individual neutral sugars to glycerol (internal standard) was found among the seven; the relationship between the peak response and concentration was strictly linear throughout the entire concentration range studied. Seventeen pectic samples, including pectins, pectates, and rhamnogalacturonan fragments, were completely prehydrolyzed by Driselase, an industrial enzyme product from Irpex lacteus, and then analyzed for their constituent sugar contents. The enzymic-HPLC method was simple, accurate, and particularly useful for routine pectin analyses.     

Colorimetric micromethods for glutaraldehyde determination by means of phenol and sulfuric acid or phenol and perchloric acid

Aqueous micromolar solutions of glutaraldehyde produce a yellow color when treated with 20% phenol in ethanol followed by concentrated sulfuric acid or with phenol in 70% perchloric acid. The absorbance at 482 or 479 nm, respectively, is linearly related to the glutaraldehyde concentration. Of the two methods developed, the sulfuric acid-phenol assay gives a higher sensitivity and the perchloric acid-phenol assay allows the determination of glutaraldehyde in the presence of sugars and proteins.     

Influence of Phenol and Phenanthrene on the Growth of Phalaris arundinacea and Phragmites australis

In constructed wetlands for the treatment of industrial effluents and in contaminated waterlogged soils, wetland plants (helophytes) are exposed to toxic chemicals. Hence, the plants' resistance to contaminants is an important prerequisite for applying phytoremediation to solve these environmental problems. For toxicity tests on the germination and growth of various helophytes (Phalaris arundinaceae and Phragmites australis), phenol, phenanthrene, and a mixture of both were used as examples of chemicals from the petrol- and coal-processing industries. The germination rate, shoot length, root length, and influence on leaves, young shoots, and dry weight were studied. Although an increase in contaminant concentration decreased plant growth (dry weight, shoot length); interestingly, the number of young shoots rose. Low contaminant concentration (about 50 mg/l in case of phenol) stimulated the plant growth. The cress seed germination test was less susceptible compared with plantlet exposure in the case of phenol and phenanthrene. Due to its low bioavailability, solid phenanthrene (without solutizer) did not significantly affect plant growth.     

Factors Influencing the in vitro Culture of the Rumen Ciliate Ophryoscolex purkynei Stein

SYNOPSIS. A method for the in vitro culture of O. purkynei was developed which permitted the continuous culture of this protozoon in clone culture for a. period of 32 months. The shortest division time was 24 hr. The concentration of cells varied between 700 and 1000/ml in the routine procedure. Variations in spination which occurred in the clone culture suggested that this characteristic was of doubtful taxonomic importance.
Ground wheat and alfalfa served as substrates but soluble sugars did not. Green plant material appeared to be necessary for continued growth of the protozoa. Ingestion of a large streptococcus was demonstrated by vital staining of a mixed population of bacteria with tetrazolium prior to incubation with the protozoan suspension in the presence of wheat.
O. purkynei can tolerate exposure to variations in osmotic pressure, temperature, and oxygen which are consonant with its transfer in nature by grooming or ingestion of contaminated food or drink.     

Tomato seed and root exudate sugars: composition, utilization by Pseudomonas biocontrol strains and role in rhizosphere colonization

The role of tomato seed and root exudate sugars as nutrients for Pseudomonas biocontrol bacteria was studied. To this end, the major exudate sugars of tomato seeds, seedlings and roots were identified and quantified using high-performance liquid chromatographic (HPLC) analysis. Glucose, fructose and maltose were present in all studied growth stages of the plant, but the ratios of these sugars were strongly dependent on the developmental stage. In order to study the putative role of exudate sugar utilization in rhizosphere colonization, two approaches were adopted. First, after co-inoculation on germinated tomato seeds, the root-colonizing ability of the efficient root-colonizing P. fluorescens strain WCS365 in a gnotobiotic quartz sand-plant nutrient solution system was compared with that of other Pseudomonas biocontrol strains. No correlation was observed between the colonizing ability of a strain and its ability to use the major exudate sugars as the only carbon and energy source. Secondly, a Tn5lacZ mutant of P. fluorescens strain WCS365, strain PCL1083, was isolated, which is impaired in its ability to grow on simple sugars, including those found in exudate. The mutation appeared to reside in zwf, which encodes glucose-6-phosphate dehydrogenase. The mutant grows as well as the parental strain on other media, including tomato root exudate. After inoculation of germinated sterile tomato seeds, the mutant cells reached the same population levels at the root tip as the wild-type strain, both alone and in competition, indicating that the ability to use exudate sugars does not play a major role in tomato root colonization, despite the fact that sugars have often been reported to represent the major exudate carbon source. This conclusion is supported by the observation that the growth of mutant PCL1083 in vitro is inhibited by glucose, a major exudate sugar, at a concentration of 0.001%, which indicates that the glucose concentration in the tomato rhizosphere is very low.     

A qualitative model for the mechanism of sugar accumulation in cold-stressed plant tissues

Summary Low temperatures induce the accumulation of soluble sugars in plant cells. An attempt is made to identify the primary site of action of low temperatures and the sequence of physiological and biochemical events leading to sugar accumulation. The integration of all the available information points to a central role of increased intracellular calcium ion concentration generated by the inhibition of ATPases concerned with its homeostasis. A positive role of a cold-induced dysfunction of mitochondrial and chloroplast electron flow is also proposed. The biological significance of an explanation of this physiological response to a stress factor relies on its categorization into the major family of those employing alternative energy-producing pathways under stress conditions. More specifically, a connection of sugar mobilization to the needs of the cold-stressed cell to employ fermentative energy-producing mechanisms is made. From this ankle of view, new ways of genetically modifying the ability of plant cells to accumulate sugars become obvious.     

New protocol for the rapid quantification of exopolysaccharides in continuous culture systems of acidophilic bioleaching bacteria

In this study, we investigate exopolysaccharide production by a bacterial consortium during the bioleaching of a cobaltiferrous pyrite. Whereas comparable studies have looked at exopolysaccharide production in batch systems, this study focuses on a continuous system comprising a series of four stirred bioreactors and reveals the difficulties in quantifying biomolecules in complex media such as bioleached samples. We also adapted the phenol/sulphuric acid method to take into account iron interference, thus establishing a new protocol for sugar quantification in bioleached samples characterised by low pH (1.4) and high iron concentration (2 g l⁻¹). This allows sugar analysis without any prior sample preparation step; only a small amount of sample is needed (0.5 ml) and sample preparation is limited to a single filtration step. We found that free exopolysaccharides represented more than 80% of the total sugars in the bioreactors, probably because stirring creates abrasive conditions and detaches sugars bound to pyrite or bacteria and that they were produced mainly in the first two reactors where bioleaching activity was greatest. However, we could not establish any direct link between the measured exopolysaccharide concentration and bioleaching activity. Exopolysaccharides could have another role (protection against stress) in addition to that in bacterial attachment.     

Rapid extracellular acidification induced by glucose metabolism in non-proliferating cells of Serratia marcescens.

The addition of glucose or other sugars to resting cells of Serratia maurcescens induced rapid acidification of the extracellular medium. This acidification was due to the catabolism of sugars. The rate of acidification depended on the carbon source and its concentration. HPLC analysis of the supernatants demonstrated that the progressive fall in pH resulted from the rapid production of lactic, acetic, pyruvic and citric acids. Other microorganisms were tested for their ability to produce this rapid acidification of the medium. This study may provide a rapid and simple method for metabolism studies.     

Phenol removal using Brassica juncea hairy roots: role of inherent peroxidase and H(2)O(2)

Removal of phenol, a major pollutant in aqueous effluents was studied using plant hairy root cultures. Among four different species of hairy roots tested, Brassica juncea showed the highest potential for phenol removal. The effect of phenol concentration and reuse in a batch system was studied using B. juncea hairy root cultures. Unlike most of the studies reported earlier, phenol removal by the hairy roots was seen to take place without the need for addition of external hydrogen peroxide (H(2)O(2)). To understand the mechanism of phenol removal, levels of peroxidase and phenol oxidase were monitored in the hairy roots. Peroxidase activity in the roots was enhanced when exposed to phenol, while phenol oxidase remained constant. Since peroxidase has a pre-requisite for H(2)O(2), the levels of H(2)O(2) were monitored for its in situ synthesis. H(2)O(2) levels were seen to increase in the presence of phenol. Thus, a mechanism wherein hairy roots also produce H(2)O(2) besides peroxidase, as a protection strategy of plant against xenobiotic stress is plausible.     

A simple colorimetric method for determination of hydrogen peroxide in plant tissues

A simple colorimetric method for determination of hydrogen peroxide in plant materials is described. The method is based on hydrogen peroxide producing a stable red product in reaction with 4-aminoantipyrine and phenol in the presence of peroxidase. Plant tissues was ground with trichloroacetic acid (5% w/v) and extracts were adjusted to pH 8.4 with ammonia solution. Activated charcoal was added to the homogenate to remove pigments, antioxidants and other interfering substances. The colorimetric reagent (pH 5.6) consisted of 4-aminoantipyrine, phenol, and peroxidase. With this method, we have determined the hydrogen peroxide concentration in leaves of eight species which ranged from 0.2 to 0.8 μmol g⁻¹ FW. Changes in hydrogen peroxide concentration of Stylosanthes guianensis in response to heat stress are also analyzed using this method.     

一种提取质粒DNA的改良方法

本文详细介绍了一种改良碱裂解法提取质粒ＤＮＡ的方法,该法采用ＮＨ４Ａｃ代替苯酚和氯份的抽提过程,得率高,质量好,完全达到了分子生物学常规实验的要求,如酶切、连接、转化大肠杆菌、ＰＣＲ等,甚至用于序列测定和植物遗传转化,该法重复性好,操作简单、实用．     

Horizontal transfer of genetic determinants for degradation of phenol between the bacteria living in plant and its rhizosphere

Phenol and other monocyclic aromatic compounds (MACs) are highly water-soluble and volatile pollutants that plants are unable to completely degrade. Endophytic bacteria with MAC-degrading ability will facilitate phytoremediation, beneficial to plant survival in contaminated soil. Endophytic bacteria, strains FX1-FX3, and rhizosphere bacteria, strains FX0, FX4, and FX5, were isolated from the root tissue of a corn plant (Zea mays) and the corn rhizosphere near a chemical plant, respectively. The strains FX1-FX5 were able to grow on phenol and reduce phenol concentration, but the strain FX0 was unable to. The strains FX1, FX3, and FX4 were classified as Pseudomonas fluorescens and FX0, FX2, and FX5 as Burkholderia cepacia. The plasmids isolated from the strains FX1-FX5 were found to possess similar traits and to be loaded with a gene encoding the catechol 2, 3-dioxygenase (C23O), a key enzyme in the phenol degradation pathway. Alignment and phylogenetic analysis inferred that in situ horizontal transfer of the C23O gene might have occurred. The horizontal transfer of the C23O gene between endophytic and rhizosphere bacteria was proved by using conjugal matings experiment, in which the transconjugants were found to acquire the plasmid with the C23O gene, able to grow on phenol and degrade phenol.     

Pre-analytical method for metabolic profiling of plant cell cultures of Passiflora garckei

Passiflora garckei cell cultures were used as a model to describe a reproducible sample preparation method. Solid phase extraction (SPE) was employed to isolate the plant metabolites for nuclear magnetic resonance (NMR) analysis and to subsequently detect the differences between yeast extract elicited and control cells. Compared with previous results obtained by using a Sephadex LH-20 column, SPE coupled with NMR spectroscopy improves the analysis of aromatic compounds e.g.: trans-feruloyl derivatives and trans-coumaroyl derivatives. Moreover, it decreases the concentration of sugars that usually overlap with many plant metabolite signals.