Comparison of Vanadium-Rich Activity of Three Species Fungi of Basidiomycetes

A comparison of vanadium-rich activity of three species fungi of Basidiomycetes, Ganoderma lucidum, Coprinus comatus, and Grifola frondosa, was studied. By fermentation and atomic absorption spectroscopy analysis, the biomass of G. lucidum and G. frondosa declined rapidly when the concentration of vanadium exceeded 0.3% but the biomass of C. comatus did not decline rapidly until the concentration of vanadium exceeded 0.4% and the content of vanadium accumulated in the mycelia was 3529.3 μg/g. After the mice were administered (intragastrically) with vanadium-rich C. comatus, the blood glucose of alloxan-induced hyperglycemic mice was decreased (p < 0.05) and the body weight of the alloxan-induced hyperglycemic mice was increased gradually. Thus, we selected C. comatus to absorb vanadium and chose 0.4% as the optimal concentration of vanadium for the pharmacological works.     

生物淋洗修复钒污染土壤的性能与机理研究

【目的】土壤重金属污染问题日益受到关注,其中钒污染逐渐成为研究热点。淋洗是土壤修复的重要手段,但存在污染大、成本高的缺点。生物淋洗技术因其经济高效且环保的特点能够应用于土壤的修复,但其对钒污染土壤的修复,认识仍非常有限。【方法】本研究采用嗜酸性氧化亚铁硫杆菌对钒污染土壤进行了生物淋洗试验,通过影响因素试验探究了钒的最佳浸出条件,并应用扫描电子显微镜-能量色散X射线谱分析了钒在淋洗过程中的变化,最后对代谢产物进行了解析。【结果】微生物次生代谢产物能促进土壤中钒的溶出。氧化亚铁硫杆菌对土壤钒的浸出效率较高,生物淋洗20 d后土壤中钒的浸出率达到27.4%,进一步的影响因素试验表明,在固体浓度为3%、接种体积为10%、初始pH值为1.8、初始Fe²⁺的浓度为3.0 g/L的条件下,土壤中钒的浸出效果最佳。SEM-EDS分析证实生物淋洗后土壤中钒含量减少,其中以非残渣态形式存在的钒更容易被浸出。代谢组学分析显示氧化亚铁硫杆菌在浸出过程中产生了大量代谢产物来应对重金属胁迫。【结论】生物淋洗技术能够有效地实现土壤钒污染的修复,本研究为钒污染土壤提供了一种环境友好的修复方式。     

Stereoselective epoxidation of <Emphasis Type="Italic">cis</Emphasis>-propenylphosphonic acid to fosfomycin by a newly isolated bacterium <Emphasis Type="Italic">Bacillus</Emphasis><Emphasis Type="Italic">simplex</Emphasis> strain S101

In industry, fosfomycin is mainly prepared via chemical epoxidation of cis-propenylphosphonic acid (cPPA). The conversion yield of fosfomycin is less than 50% in the whole process and a large quantity of waste is produced. Biotransformation by microorganisms is an alternative method of preparation. This kind of conversion is more delicate, environmentally friendly, and the conversion yield of fosfomycin would be higher. In this work, an aerobic bacterium capable of transforming cPPA to fosfomycin was isolated. The organism, designated as strain S101, was identified as Bacillus simplex by morphological and physiological characteristics as well as by analysis of the gene encoding the 16S rRNA. Fosfomycin was assayed by two means, bioassay and gas chromatography (GC). Glycerol was a good carbon source for growth and cPPA conversion of strain S101. When cPPA was used as the sole carbon source, neither growth nor conversion to fosfomycin occurred. The optimum cPPA concentration in the conversion medium was 2,000 μg ml⁻¹. After 6 days of incubation, the concentration of fosfomycin reached its maximum level (1,838.2 μg ml⁻¹), with a conversion ratio of 81.3%. Air was indispensable for the growth but not for the conversion to fosfomycin. Furthermore, vanadium ions were found to be essential for the conversion. High concentrations of cPPA had fewer inhibitory effects on the growth of strain S101.     

Reduction of vanadium(V) by <Emphasis Type="Italic">Enterobacter cloacae</Emphasis> EV-SA01 isolated from a South African deep gold mine

Dissimilatory reduction of vanadium(V) by Enterobacter cloacae EV-SA01, isolated from a gold mine at 1.6 km below surface, is shown to occur anaerobically as well as aerobically. Growth rates were unaffected by up to 2 mM V₂O₅. Reduction of vanadium(V) was growth phase-dependent and resulted in cell deformities and precipitation of the vanadium in its lower oxidation states. The vanadate reductase activity was membrane-associated and coupled the oxidation of NADH to the reduction of vanadate.     

Prenatal and postnatal exposure to vanadium and the immune function of children

BackgroundThe immunotoxicity induced by vanadium exposure have been reported in some toxicology researches. However, evidence from population-based epidemiological studies was lacking.MethodsThis study was conducted to assess the associations between prenatal and postnatal exposure to vanadium and immune function of children. A total of 407 pre-school aged children were followed, whose peripheral blood was collected for T lymphocyte subsets and inflammatory cytokines analysis, as well as vanadium concentration measurement. Maternal urine samples were also collected to measure vanadium concentration. We used generalized linear models to evaluate the associations of maternal and children vanadium concentration with children’s immune function. Stratification analysis was further conducted to explore the potential gender-specific effects.ResultsThe geometric means of vanadium concentration in maternal urine and children plasma were 0.85 and 1.12 μg/L, respectively. Maternal urinary vanadium was inversely associated with the percentage of CD3⁺CD4⁺ cells [-5.53 % (-10.38 %, -0.41 %)] and absolute counts of CD3⁺ cells [-2.43 % (-5.05 %, 0.25 %)], and we only observed significant negative associations in males when stratifying by fetal gender. Children plasma vanadium was also associated with reduced absolute counts of CD3⁺ cells [-5.25 % (-9.57 %, -0.73 %)], but gender-specific effects were not observed. No significant associations of vanadium exposure with cytokines were found.ConclusionsPrenatal and postnatal exposure to vanadium had suppressive impacts on childhood cellular immune. Further studies are needed to confirm our findings.     

Determination of subnanomolar concentrations of vanadium in environmental water samples using flow injection with luminol chemiluminescence detection

A flow injection chemiluminescence method is described for the determination of subnanomolar concentrations of vanadium in environmental water samples. The procedure is based on the oxidation of luminol in the presence of dissolved oxygen catalyzed by vanadium(IV). Vanadium(V) reduction and preconcentration of vanadium(IV) was carried out using in‐line silver reductor and 8‐hydroxyquinoline chelating columns at pH 3.15, respectively. The calibration graph for vanadium(IV) was linear in the concentration range of 0.025–10 µg/L with relative standard deviation in the range of 0.4–5.58%. The detection limit (3s blank) was 3.8 × 10^?3 µg/L without preconcentration; when the vanadium(IV) was preconcentrated with an 8‐HQ column for 1 min (2.0 mL of sample loaded), the detection limit of 5.1 × 10^?4 µg/L was achieved. One analytical cycle can be completed in 2.0 min. The analysis of certified reference materials (CASS‐4, NASS‐5 and SLRS‐4) by the proposed method showed good agreement with the certified values. The method was successfully applied to the determination of total dissolved vanadium in environmental water samples. Copyright © 2010 John Wiley & Sons, Ltd.     

Bioaccumulation of Vanadium by Vanadium-Resistant Bacteria Isolated from the Intestine of <Emphasis Type="Italic">Ascidia sydneiensis samea</Emphasis>

Isolation of naturally occurring bacterial strains from metal-rich environments has gained popularity due to the growing need for bioremediation technologies. In this study, we found that the vanadium concentration in the intestine of the vanadium-rich ascidian Ascidia sydneiensis samea could reach 0.67 mM, and thus, we isolated vanadium-resistant bacteria from the intestinal contents and determined the ability of each bacterial strain to accumulate vanadium and other heavy metals. Nine strains of vanadium-resistant bacteria were successfully isolated, of which two strains, V-RA-4 and S-RA-6, accumulated vanadium at a higher rate than did the other strains. The maximum vanadium absorption by these bacteria was achieved at pH 3, and intracellular accumulation was the predominant mechanism. Each strain strongly accumulated copper and cobalt ions, but accumulation of nickel and molybdate ions was relatively low. These bacterial strains can be applied to protocols for bioremediation of vanadium and heavy metal toxicity.     

钒钛磁铁尾矿土壤中水黄皮根瘤菌铁耐受性与钝化能力研究

铁是好氧微生物生长所必需的元素,而铁污染土壤环境中的根瘤菌是否对高浓度铁具有耐受性和钝化能力尚不清楚。以攀枝花钒钛磁铁尾矿土壤作为基质进行水黄皮共生根瘤菌捕获实验,获得水黄皮共生根瘤并从中分离纯化出根瘤菌39株。通过Fe~(2+)/Fe~(3+)耐受性和钝化能力测试筛选出耐受性和钝化能力均强的优势菌株PZHS20、PZHS90、PZHS87,其对Fe~(2+)的最大耐受质量浓度为1 600 mg/L,其中PZHS20在200 mg/L Fe~(2+)溶液中钝化效率最大,为73.54%;PZHS90对Fe~(3+)的最大耐受质量浓度为1 600 mg/L,而PZHS20和PZHS87对Fe~(3+)的最大耐受质量浓度为1 800 mg/L,其在200 mg/L Fe~(3+)溶液中钝化效率分别为84.25%和81.95%。16S rRNA基因系统进化分析将PZHS20鉴定为苍白杆菌(Ochrobactrum),将PZHS90和PZHS87鉴定为慢生根瘤菌(Bradyrhizobium)。研究结果表明,钒钛磁铁尾矿土壤中的水黄皮根瘤菌具有不同程度的Fe~(2+)/Fe~(3+)耐受性和钝化能力,筛选出的优势菌株为进一步利用水黄皮-根瘤菌联合修复高浓度铁污染土壤提供可利用的菌株资源。     

A Comparison of Hypoglycemic Activity of Three Species of Basidiomycetes Rich in Vanadium

The hypoglycemic activity of fermented mushroom of three fungi of basidiomycetes rich in vanadium was studied in this paper. Alloxan- and adrenalin-induced hyperglycemic mice were used in the study. The blood glucose and the sugar tolerance were determined. After the mice were administered (ig) with Coprinus comatus rich in vanadium, the blood glucose of alloxan-induced hyperglycemic mice decreased (p < 0.05), ascension of blood glucose induced by adrenalin was inhibited (p < 0.01) and the sugar tolerance of the normal mice was improved. However, the same result did not occur in Ganoderma lucidum and Grifola frondosa group. Compared with Ganoderma rich in vanadium and Grifola frondosa rich in vanadium, the hypoglycemic effects of Coprinus comatus rich in vanadium on hyperglycemic animals are significant; it may be used as a hypoglycemic food or medicine for hyperglycemic people.     

Plant regeneration from protoplasts of <Emphasis Type="Italic">Musa acuminata</Emphasis> cv. Mas (AA) via somatic embryogenesis

A protocol for plant regeneration from protoplasts of Musa acuminata cv. Mas (AA) via somatic embryogenesis was developed. Viable protoplasts were isolated from embryogenic cell suspensions at a yield of 1.2 × 10⁷ protoplasts/ml packed cell volume (PCV). Liquid and feeder layer culture systems with medium-A and medium-B were used for protoplast culture. In liquid culture system, medium-B was more efficient for inducing cell division (17.5% at 14 days) and colony formation (6.7% at 28 days) than medium-A. However, all protoplast-derived cell colonies (PDCC) obtained from liquid culture system could not develop further. In feeder layer culture system, there was no significant difference between medium-A and medium-B on cell division and colony formation of the cultured protoplasts, and the cell division frequency at 14 days and colony formation frequency at 28 days were 24.5% and 11.2%, respectively, in medium-B. Comparative study on the effects of BAP (2.2 μM, 4.4 μM, 8.8 μM), zeatin (0.4 μM, 0.8 μM, 1.2 μM) and TDZ (0.2 μM, 0.4 μM, 0.6 μM) on embryo formation of PDCC from feeder-layer culture indicated that TDZ was best. TDZ at 0.4 μM induced 7906 mature embryos per ml PCV PDCC, which was 4-fold the frequency as with BAP at 4.4 μM, 7.5-fold as with zeatin at 0.8 μM and 150-fold as control medium (no mentioned cytokinins) after 45 days on M3 medium. About 44% of the mature embryos were converted into plantlets with poor root system after subculture on M4 medium. Root further development of regenerated plantlets was promoted by addition of activated charcoal (AC) to MS basal medium.     

Purification of Sulfated Fucoglucuronomannan Lyase from Bacterial Strain of <Emphasis Type="Italic">Fucobacter marina</Emphasis> and Study of Appropriate Conditions for Its Enzyme Digestion

A marine bacterial strain, Fucobacter marina, produced extracellular sulfated fucoglucuronomannan (SFGM) lyase when cultivated in the presence of crude SFGM obtained from fucoidan of Kjellmaniella crassifolia (brown algae) by cetyl pyridinium chloride fractionation. For the SFGM lyase assay, SFGM fraction separated from K. crassifolia fucoidan by anion exchange column chromatography was used as the substrate. The extracellular SFGM lyase was purified to homogeneity on an electrophoresis gel with 4240-fold purity at 13.8% yield. The enzyme proved to be a monomer, since gel filtration and sodium dodecyl sulfate polyacrylamide gel electrophoresis gave the same relative molecular mass of 67,000. The enzyme specifically digested SFGM but did not digest any other uronic-acid-containing polysaccharides tested. The optimum conditions for the enzyme reaction were around pH 7.5, 43°C, and 0.4 M NaCl concentration. The enzyme was strongly inhibited by CuCl₂ and ZnCl₂, and also by some sulfhydryl reagents.     

Natural Infections Caused by the Fungus <Emphasis Type="Italic">Beauveria bassiana</Emphasis> as a Pathogen of <Emphasis Type="Italic">Musca domestica</Emphasis>in the Neotropic

A survey for entomopathogenic fungi of Musca domestica adults was conducted in poultry houses in La Plata, Buenos Aires province, Argentina, during the years 2002 and 2003. Adult house flies were found infected with the fungus Beauveria bassiana (Bals.) Vuill. (Deuteromycotina: Hyphomycetes) from field collections, with a natural infected prevalence between 0.4–1.45%. This is the first record of natural infections of house flies caused by B. bassiana for the neotropics. Pathogenicity assays under laboratory conditions showed 94% adult mortality at 14 days post challenge. CIC fellow     

Production of surfactant and detergent-stable,halophilic, and alkalitolerant alpha-amylase by a moderately halophilic <Emphasis Type="Italic">Bacillus</Emphasis> sp. Strain <Emphasis Type="Italic">TSCVKK</Emphasis>

A moderately halophilic alkalitolerant Bacillus sp. Strain TSCVKK, with an ability to produce extracellular halophilic, alkalitolerant, surfactant, and detergent-stable alpha-amylase was isolated from soil samples obtained from a salt-manufacturing industry in Chennai. The culture conditions for higher amylase production were optimized with respect to NaCl, substrate, pH, and temperature. Maximum amylase production of 592 mU/ml was achieved in the medium at 48 h with 10% NaCl, 1% dextrin, 0.4% yeast extract, 0.2% tryptone, and 0.2% CaCl₂ at pH 8.0 at 30 °C. The enzyme activity in the culture supernatant was highest with 10% NaCl at pH 7.5 and 55 °C. The amylase that was partially purified by acetone precipitation was highly stable in various surfactants and detergents. Glucose, maltose, and maltooligosaccharides were the main end products of starch hydrolysis indicating that it is an alpha-amylase.     

Effects of phytohormones on mycelial growth and exopolysaccharide biosynthesis of medicinal mushroom <Emphasis Type="Italic">Pellinus linteus</Emphasis>

Effects of phytohormones including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and 1-naphthalentacetic acid (NAA) on mycelial growth of medicinal mushroom Phellinus linteus were investigated. Under the optimal IAA, IBA and NAA concentration of 1.0, 1.5 and 5.0 mg/l, the maximal mycelial diameter reached 8.6 ± 0.4, 7.3 ± 2.6 and 9.0 ± 1.0 mm, respectively. The mycelial biomass and exopolysaccharide (EPS) production with addition of 5.0 mg/l NAA in a shake flask were 6.24 ± 0.18 g/l at 168 h and 0.86 ±0.01 g/l at 192 h, which were enhanced by 15.98 and 56.36% compared to the control, respectively. However, the molecular weight and infrared spectrum of EPS were coincident with the control. Results indicated that NAA at the proper concentration was beneficial in stimulating mycelial growth and EPS biosynthesis, whereas it could not alter the molecular structure of EPS. An erratum to this article can be found at     

Mn<Superscript>2+</Superscript> enhances theanine-forming activity of recombinant glutamine synthetase from <Emphasis Type="Italic">Bacillus subtilis</Emphasis> in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Bacillus subtilis glutamine synthetase (GS) was highly expressed (about 86% of total protein) as soluble protein in Escherichia coli BL21(DE3) containing pET28a-glnA, which was induced by 0.4 mM IPTG in LB medium, and maximal theanine-forming activity of the recombinant GS induced in LB is 6.4 U/mg at a series concentration (0–100 mM) of Mn²⁺ at optimal pH 7.5. In order to get GS with high theanine-forming activity, safety, and low cost for food and pharmaceutics industry, M9-A (details are described in “Materials and methods”) and 0.1% (w/v) lactose were selected as culture medium and inducer respectively. Recombinant GS was also highly expressed (84% of total protein) and totally soluble in M9-A and the specific activity of the recombinant GS is 6.2 U/mg which is approximate to that (6.4 U/mg) induced in LB in the presence of 10 mM Mn²⁺ at optimal pH 7.5. The activity is markedly higher activated by Mn²⁺ than that by other nine bivalent cations. Furthermore, M9-B (5 μM Mn²⁺ was added into M9-A) was used to culture the recombinant strain and theanine-forming activity of the recombinant GS induced in M9-B was improved 20% (up to 7.6 U/mg). Finally, theanine production experiment coupled with yeast fermentation system was carried out in a 1.0 ml reaction system with 0.1 mg crude GS from M9-B or M9-A, and the yield of theanine were 15.3 and 13.1 g/L by paper chromatography and HPLC, respectively.     

A kinetic method for determination of free vanadium(IV) and (V) at trace level concentrations

A kinetic method based on alkaline phosphatase has been developed to measure free trace levels of vanadium(IV) and (V). The method involves measuring the rate of the alkaline phosphatase-catalyzed hydrolysis of p-nitrophenyl phosphate with (Vi) and without (Vo) a competitive inhibitor in the assay. Michaelis-Menten kinetics for a competitive inhibitor was used to express the relationship between Vo/Vi and the inhibitor concentration. Measuring both Vo and Vi thus yields a Vo/Vi ratio that allows calculation of the competitive inhibitor concentration. Determination of free vanadium in complex fluids can be accomplished by comparing the ratio of rates of p-nitrophenyl phosphate hydrolysis with and without a sequestering agent to the ratios of rates measured on addition of a known vanadium concentration. Free vanadium(V) can conveniently be measured from 10(-7) to 10(-5) M and free vanadium(IV) can be measured at 10(-8) M and above. The error limits on the vanadium determinations range from +/- 3 to +/- 12% of the concentration under investigation depending on the conditions under which the assay was conducted.     

Calcium alginate entrapment of the yeast Rhodosporidium toruloides for the kinetic resolution of 1,2-epoxyoctane

Resting cells of the yeast Rhodosporidium toruloides (UOFS Y-0471) were immobilised in calcium alginate beads for the enantioselective kinetic resolution of racemic-1,2-epoxyoctane. The initial activity exhibited by immobilised cells was almost 50% lower than that of the free counterpart but was extremely stable when compared to the free cells. The concentration of the immobilised biomass had no effect on apparent enzyme activity but did lead to a decrease in single cell activity. An increase in both the alginate and CaCl₂ concentrations used for bead preparation led to a decrease in enzyme stability. An increase in the alginate concentration led to an increase in bead diameter. The stoichiometric equation for cross-linking of alginate was only obeyed when CaCl₂ concentrations higher than 0.4 M were utilised for bead preparation.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of Indian Kino (<Emphasis Type="Italic">Pterocarpus marsupium</Emphasis> Roxb.) using Thidiazuron

An efficient protocol was developed for micropropagation of an economically important timber-yielding multipurpose tree, Pterocarpus marsupium Roxb. Multiple shoots were induced from cotyledonary nodes (CNs) derived from 18-d-old axenic seedlings on Murashige and Skoog (MS) medium supplemented with thidiazuron (TDZ) (0.1–10 μM). The highest shoot regeneration frequency (90%) and maximum number (15.2 ± 0.20) of shoots per explant was recorded on MS medium amended with 0.4 μM TDZ. Continuous presence of TDZ inhibited shoot elongation. In the primary medium, TDZ-initiated cultures were transferred to the secondary medium supplemented with another cytokinin, 6-benzyladenine (BA), for shoot growth and elongation. Maximum (90%) shoot elongation with an average shoot length of 5.4 ± 0.06 cm was observed at 5 μM BA. To further enhance the number of shoots per explant, mother tissue was repeatedly subcultured on fresh shoot induction medium after each harvest of newly formed shoots. Thus, by adopting this strategy, an average of 44 shoots per explant could be obtained. About 65% of in vitro regenerated shoots produced a maximum number (4.4 ± 0.2) of roots per shoot by a two-step culture procedure employing pulse treatment and subsequent transfer of treated shoots to a low concentration of 0.2 μM indole-3-butyric acid along with phloroglucinol (3.96 μM). The in vitro-raised plantlets were successfully acclimatized first under culture room conditions, then to greenhouse with 70% survival rate.     

Bioavailability of Vanadium Extracted by EDTA, HCl, HOAC, and NaNO3 in Topsoil in the Panzhihua Urban Park, Located in Southwest China

Bioavailable vanadium was evaluated on the basis of soil vanadium single-extraction with ethylenediaminetetraacetic acid (EDTA), hydrochloric acid (HCl), acetic acid (HOAc), and sodium nitrate (NaNO(3)) in Panzhihua urban park. The soil vanadium concentration extracted by HOAc was 0.01-2.07?mg?kg(-1), by EDTA 0.28-7.03?mg?kg(-1), by NaNO(3) 0.07-0.53?mg?kg(-1), and by HCl 0.19-1.36?mg?kg(-1). The bioavailable vanadium (bioavailable fraction) obtained with HOAc was 0.01-1.33%, with EDTA 0.27-4.09%, with NaNO(3) 0.13-0.72%, and with HCl 0.06-0.28%. In addition, the impact of soil properties, soil nutrients, and soil enzyme activities on bioavailability of vanadium is discussed in this study. Based on the characteristics of bioavailable vanadium in the soil, ecological and health risks should have been given more attention in the studied area.