Enhancing bioremoval of textile dyes by eight fungal strains from media supplemented with gelatine wastes and sucrose

Eight Aspergillus strains were found to be successful in removing textile dyes from liquid media. These fungal strains were grown on medium containing: gelatine wastes and sucrose, as sources of nitrogen and carbon to test the possible speed up of the dyes removing while fungus biomass is building up in the media. The growth of fungal strains ranged from 10 to 110 mg biomass dry weight/100 ml medium. This growth induced high decolorization percentages, which ranged 33-95% within eight days. Two textile dyes Direct brown and Polar red were included in the study. The growth of the fungal strains as well as decolorization percentage of the dyes increased after 5, 6, and 8 days from incubation time with most tested strains. With Direct brown dye the strains number 2, 5, 31 and 37 recorded the highest percentage of decolorization (91, 92, 93 and 95 respectively) after incubation for 6 days. Fungal strains Aspergillus 5 and 31 gave the highest mycelium dry weight being 110 mg. Most of fungal strains induced 86 to 95 percentage of decolorization after 6 days incubation with Polar red dye. The possible toxicity of the remaining supernatant media after fungal biomass removal was tested by Ames test to assess the residual mutagenic agents remaining after dye removal, using three strains of Salmonella typhimurium (TA 1535, TA 1537, TA 1538). The results showed that the toxicity of the dyes, measured by Ames test could be removed by the dye absorption on the fungal biomass.     

Isolation and characterization of microorganisms capable of decolorizing various triphenylmethane dyes

Various soil and sludge samples collected from the vicinity of textile dyeing industries and waste disposal sites were used for enrichment of microbial population in the presence of triphenylmethane (TPM) dye Acid Violet-17 (AV-17). Twenty-five (25) isolates were screened for their ability to decolorize AV-17 dye added at a rate of 10 mgl(-1) in mineral salts medium (MSM) agar plates. Five bacterial isolates belonging to Bacillus sp., Alcaligenes sp. and Aeromonas sp. were selected on the basis of their higher decolorization ability and were used to develop a bacterial consortium. The consortium was able to efficiently decolorize various TPM dyes viz. Acid Violet-17 (86%), Acid Blue-15 (85%), Crystal Violet (82%), Malachite Green (82%) and Brilliant Green (85%). The consortium will be further used for designing efficient and cost effective treatment system for effluents of textile processing industries (TPI).     

Rhamnolipid from Pseudomonas desmolyticum NCIM-2112 and its role in the degradation of Brown 3REL

The biosurfactant produced by Pseudomonas desmolyticum NCIM 2112 (Pd 2112) was confirmed as rhamnolipid based on the formation of dark blue halos around the colonies in CTAB-methylene blue agar plates and the content of rhamnose sugar. The average yield of rhamnolipid was 0.398 g/l/day when grown on hexadecane as sole carbon source. Pd 2112 emulsification potential associated with cell free culture broth was stable for 72 h using various hydrocarbons and vegetable oils. Chemical structure of the biosurfactant was identified as mono-rhamnolipid (Rha-C(6) -C(8) ) using HPTLC, fourier transform infrared spectroscopy, (1) H and (13) C NMR and gas chromatography-mass spectroscopy analysis. Pd 2112 mono-rhamnolipid (1 mg/ml) had increased permeabilization of Bacillus sp VUS NCIM 5342 and increased decolorization rate of textile dye Brown 3REL by 50%. Extracellular activities of lignin peroxidase and veratryl alcohol oxidase, enzymes involved in dye degradation, were significantly increased in the presence of mono-rhamnolipid by 324.52% and 100% respectively. Scanning electron micro-scopy observations revealed that rhamnolipid did not exert any disruptive action on Bacillus cells as compared to Tween 80. The mono-rhamnolipid of Pd 2112 has potential for its application in biodegradation of textile dyes.     

Production of laccase from Pleurotus florida using agro‐wastes and efficient decolorization of Reactive blue 198

Pleurotus florida NCIM 1243 produced laccase as the dominant lignolytic enzyme during the dye decolorization. Banana peel was the best substrate for extracellular laccase production under solid state fermentation when compared to mandarin peel and cantaloupe peel. The maximum activity of laccase (5.4 U/g) was detected on the 10 day. The ratio of banana peel: mandarin peel: cantaloupe peel (5:2:3) showed increased production of laccase (6.8 U/g). P. florida produced two extracellular laccase isoenzymes (L1 and L2). The half life of laccase at 60 °C was 2 h and at 4 h it retained 25% residual activity. P. florida laccase showed high thermostability and an interesting difference was noticed in the behavior of laccase isoenzymes at different temperature. The L1 isoenzyme of laccase showed remarked thermostability at 60 °C in the native PAGE when compared to L2 isoenzyme. The optimum pH, temperature and enzyme concentration for maximum decolorization was found to be 4.5, 60 °C and 1.2 U/ml, respectively. Partially purified laccase enzyme showed excellent decolorization activity to Reactive blue 198. The maximum decolorization (96%) was observed at lower dye concentrations (50–100 ppm) which decreased markedly when the dye concentration was increased beyond 150 ppm. The thermostable laccase of P. florida could be effectively used to decolorize the synthetic dyes in the textile effluent and other biotechnological applications. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Adsorptive removal of textile dyes from aqueous solutions by dead fungal biomass

Dead fungal biomass prepared from Phanerochaete chrysosporium and Funalia trogii was tested for their efficiency in removal of textile dyes. The effects of contact time, initial dye concentration, amount of dead biomass and agitation rate on dye removal have been determined. Removal of all dyes required a very short time (60 min). Experimental results show that, P. chrysosporium was more effective than F. trogii . An increase in the amount of dead biomass positively affected of the dye removal. The removal efficiency of different amount of biomass was in order 1 g > 0.5 g > 0.2 g > 0.1 g. The highest removal was obtained at 150-200 rpm. Slightly lower removing activities were found at lower agitation rates. This study showed that it was possible to remove textile dyes by dead biomass of P. chrysosporium .     

No effect of trans sodium crocetinate on maximal O(2) conductance or V(O(2),max) in moderate hypoxia

The lumped parameter describing skeletal muscle diffusional conductance for O(2), DM(O(2)), reflects all of the resistances for O(2) in moving from red cell to muscle fiber mitochondria. The purpose of our study was to determine if the carotenoid compound, trans sodium crocetinate (TSC), which has been reported to increase the diffusivity of O(2) in plasma, improves DM(O(2)) and thus, V(O(2),max) in maximally contracting in situ skeletal muscle. V(O(2),max) was measured in the isolated perfused canine gastrocnemius (n=5) during 3 min of isometric tetanic contractions at 1 Hz, while the animal was breathing 12% O(2) (PA(O(2))=32+/-2 Torr, mean+/-S.E.) under two experimental conditions. The first was a control contraction period and the second (following 60 min recovery) was performed within 5 min after infusion of a 0.1 mg x ml(-1) solution of TSC (total dose 100 microg kg(-1)). There were no significant differences in convective O(2) delivery (11.9+/-2.3 vs. 12.1+/-2.2 ml x min(-1) x 100 g(-1)), V(O(2),max) (9.5+/-1.5 vs. 9.6+/-1.5 ml x min(-1) x 100 g(-1)) or calculated DM(O(2)) (0.37+/-0.03 vs. 0.37+/-0.04 ml x min(-1) x 100 g(-1) x Torr(-1)) between contraction periods. As such, our results show that TSC does not improve performance in maximally contracting canine gastrocnemius muscle in situ under moderately hypoxic conditions, suggesting either that TSC in this situation does not increase plasma O(2) diffusivity or that this step in O(2) diffusion from red cell to myocyte does not constrain DM(O(2)).     

Ryanodine receptors and the mediation of Ca2+-dependent anion secretion across rat colon

The properties of the Na(+)-Ca(2+) exchanger in isolated crypts from rat colon were studied using the Fura-2 imaging technique. The transport mode of the exchanger was reversed by replacing extracellular Na(+) by the impermeable cation, N-methyl-D-glucamine (NMDG(+)), so that the transporter mediated a Ca(2+) influx into the cells. Depletion of intracellular Ca(2+) stores by inhibitors of sarcoplasmatic endoplasmatic calcium ATPases (SERCA), i.e., cyclopiazonic acid (10(-5) mol l(-1)) or thapsigargin (10(-6) mol l(-1)), reduced the increase in [Ca(2+)](i) evoked by superfusion with NMDG(+), suggesting a cross-talk between the exchanger and the Ca(2+) stores. However, measurement of Ca(2+) influx with the Mn(2+) quench technique revealed that the activity of the exchanger was independent of the filling state of the stores. Instead, the obvious inhibition of the [Ca(2+)](i)response by SERCA blockers was due to a reduction of Ca(2+)-induced Ca(2+) release after inhibition of store-refilling. The functional presence of ryanodine receptors was demonstrated by the increase in [Ca(2+)](i)evoked by ryanodine (10(-7) to 3x10(-4) mol l(-1)) in a concentration-dependent manner. This effect was mimicked by cADP ribose (10(-5) mol l(-1)) in crypts permeabilized with saponin (10 mg l(-1)). Ruthenium red (5x10(-5) mol l(-1)) or high concentrations of ryanodine (3x10(-4) mol l(-1)) inhibited this response. In Ussing chamber experiments ruthenium red (5x10(-4) mol l(-1)) or a high concentration of ryanodine (10(-3) mol l(-1)) inhibited the increase in short-circuit current evoked by the cholinergic agonist, carbachol (5x10(-5) mol l(-1)). Consequently, Ca(2+)-induced Ca(2+) release may act as kind of amplifier during Ca(2+)-dependent Cl(-) secretion in order to maintain a long-lasting increase in the intracellular Ca(2+) concentration.     

Microflora involved in textile dye waste removal

Textile dyes are heavily used in factories for coloring different cloth materials. This work was designed to identify microorganisms capable of removing textile dyes, either by biodegradation or by biosorption. We expected to isolate microorganisms adapted to high dye concentrations from sites near textile industry complex. An experiment was conducted to study the efficiency of the isolates in removing textile dyes. The tested dyes were used as carbon and nitrogen sources for isolation of soil and/or water microorganisms capable of removing textile dyes wastes from factories effluent. The results indicated the low efficiency of both bacteria and actinomycetes in clean-up the effluent from the waste dyes in 10-21 days. On the other hand six fungal isolates were obtained by plating factory effluent on Martin's medium and media containing dyes as the sole source of carbon and nitrogen for growth. These isolates fell in two genera, Aspergillus and Trichoderma. Results of these studies revealed the potential capacity of these fungi to decolorize the tested dyes in comparatively short time (2-24 hours) indicating strong efficiency of dye bioremediation by the fungal isolates. Since the process involved is mostly fast interaction between the fungal mycelium and the dye in the media, the possible mechanism could be based on a biosorption of such chemicals on the intact fungal biomass, rather than direct biodegradation of the compounds.     

Meningeal diffusion of cefpirome in adults

Cefpirome is a new aminothiazolyl cephalosporin with a low protein binding, a long half-life of elimination and a wide antibacterial spectrum including pseudomonas and staphylococcus. We studied its diffusion into the cerebrospinal fluid (CSF). Cefpirome, 2 g, was administered intravenously over 3 min. Nineteen patients, aged 12-75 y (mean +/- SD = 40 +/- 20) were studied: 13 had meningitis (septic = 6; chronic = 2; viral = 4). Seric and CSF samples were assayed by the high pressure liquid chromatography (HPLC) procedure. Results at 1, 3, 6, 9 and 12 hours after the infusion were (mean +/- SD) 62.44 +/- 19.8 mg/l, 26.51 +/- 3.7 mg/l, 10.19 +/- 3.3 mg/l, 3.99 +/- 2.3 mg/l, 2 +/- 1.72 mg/l in the serum and 1.1 +/- 1 mg/l, 2.6 +/- 1.8 mg/l, 2.83 +/- 1.7 mg/l, 1.92 +/- 1 mg/l, 1.83 +/- 0.36 mg/l in CSF of bacterial meningitidis respectively. The half-life of elimination were 2.45 h and 9.8 h in the blood and CSF respectively. The area under the curve CSF/serum ratio was 28%. We conclude that cefpirome concentrations in the CSF were above the minimal inhibitory concentrations of almost all the bacteria causing meningitis.     

Ageing diminishes endothelium-dependent vasodilatation and tetrahydrobiopterin content in rat skeletal muscle arterioles

Ageing reduces endothelium-dependent vasodilatation through an endothelial nitric oxide synthase (NOS) signalling pathway. The purpose of this study was to determine whether arginase activity diminishes endothelium-dependent vasodilatation in skeletal muscle arterioles from old rats, and whether NOS substrate (L-arginine) and cofactor (tetrahydrobiopterin; BH(4)) concentrations are reduced. First-order arterioles were isolated from the soleus muscle of young (6 months old) and old (24 months old) male Fischer 344 rats. In vitro changes in luminal diameter in response to stepwise increases in flow were determined in the presence of the NOS inhibitor N(G)-nitro-L-arginine methyl ester (l-NAME, 10(-5) mol l(-1)), the arginase inhibitor N(omega)-hydroxy-nor-L-arginine (NOHA, 5 x 10(-4) mol l(-1)), exogenous L-arginine (3 x 10(-3) mol l(-1)) or the precursor for BH(4) synthesis sepiapterin (1 micromol l(-1)). Arteriolar L-arginine and BH(4) content were determined via HPLC. Ageing decreased flow-mediated vasodilatation by 52%, and this difference was abolished with NOS inhibition. Neither inhibition of arginase activity nor addition of exogenous L-arginine had any effect on flow-mediated vasodilatation; arteriolar l-arginine content was also not different between age groups. BH(4) content was lower in arterioles from old rats (94 +/- 8 fmol (mg tissue)(-1)) relative to controls (234 +/- 21 fmol (mg tissue)(-1)), and sepiapterin elevated flow-mediated vasodilatation in arterioles from old rats. These results demonstrate that the impairment of endothelium-dependent vasodilatation induced by old age is due to an altered nitric oxide signalling mechanism in skeletal muscle arterioles, but is not the result of increased arginase activity and limited L-arginine substrate. Rather, the age-related deficit in flow-mediated vasodilatation appears to be the result, in part, of limited BH(4) bioavailability.     

The effect of azo dyes on the formation of immune complexes.

The azo dyes were found to react with antibodies aggregated in immune complex in a similar way to heat-aggregated IgG. The whole micelles of the dye, instead of single molecules, are fixed to antibodies. In a consequence, the number of dye molecules, determined per one antibody molecule, differs but may be as large as 50-60. The dye, bound to antibody complexed with antigen, enhances its affinity to antigen. The increase of affinity, expressed as the relation of changed by the dye association constants to its initial value, was found to be 6.27 x 10(8):1. The corresponding energy change, calculated from this value, equals 11.97 kcal/mol. The resulting amount of antibodies, bound to antigen, is essentially enlarged. The enhancement effect does not seem to depend on the number of antibodies bound to the red cell up to about 3 x 10(4) molecules. It indicates that in this range a single antibody binding may be affected by the dye. The situation changes at growing antibody densities in the complex when the dye-antibody network, formed by crossbridged molecules, additionally increases the stability of the immunoglobulin molecules engaged in the complex.     

Gastric emptying and fluid availability after ingestion of glucose and soy protein hydrolysate solutions in man

The double sampling gastric aspiration method was used to measure the effect of energy content on the rate of gastric emptying of glucose and soy protein hydrolysate solutions. The net rate of absorption of water from these solutions was assessed using deuterium oxide as a tracer for water. Six healthy male subjects were each studied on four separate occasions using a test drink volume of 600 ml. The half emptying times (t 1/2, median (range)) of the iso-energetic soy protein hydrolysate (6P, 60 g l(-1), 36 (14-39) min) and glucose (7G, 70 g l(-1), 25 (19-29) min) solutions were similar. These two solutions (6P, 7G) delivered energy to the small intestine at similar rates, and resulted in similar rates of accumulation of the deuterium tracer in the circulation. The dilute glucose solution (LG, 23 g l(-1)) was emptied faster (t 1/2 13 (11-19) min) and resulted in a faster rate of tracer accumulation in the circulation than any of the other solutions, including the iso-osmotic soy protein solution (LG 311 +/- 5 mosmol kg(-1), 6P 321 +/- 24 mosmol kg(-1)). The concentrated soy protein hydrolysate solution (12P, 120 g l(-1)) emptied more slowly (t 1/2 80 (44-120) min) than the more dilute solutions. The rate of energy delivery to the small intestine from 12P was similar to that from 6P for the first 50 min after ingestion, and similar to that from 7G at all sample points. These results indicate that the iso-energetic solutions of glucose and soy protein hydrolysate used in this study are emptied from the stomach at similar rates and result in similar rates of fluid availability after ingestion.     

Calcification of allograft aortic wall in a rat subdermal model. Pathophysiology and inhibition by Al3+ and aminodiphosphonate preincubations.

Aortic allograft conduits and valves frequently undergo calcific degeneration. To study this problem, a rat subdermal model of nonvalved aortic wall allograft calcification was characterized, and experimental studies were carried out to test the hypothesis that aortic allograft preincubation in either amino-propanehydroxydiphosphonate (APDP) or AlCl3 would inhibit calcification in a rat subdermal model. Fresh thoracic aortas were harvested under sterile conditions from male Sprague-Dawley rats (350-400 g). APDP aortas were preincubated immediately in either 4 x 10(-3) mol/l, 4 x 10(-4) mol/l, or 4 x 10(-5) mol/l [14C] APDP (37 degrees C, pH 7.4) and controls were incubated in 0.05 mol/l HEPES buffer (pH 7.4, 37 degrees C, 30 min). Al3+ aortas were preincubated in either 10(-1) mol/l, 10(-2) mol/l, or 10(-3) mol/l AlCl3. Pretreated aortas were next implanted subdermally in weanling rats (3-week-old, male, Sprague-Dawley, 50-60 g) and retrieved after 21 days. Control explants retrieved at intervals up to 21 days demonstrated progressive calcification with bulk aortic allograft Ca2+ levels increasing from a preimplant value of 0.8 +/- 0.1 micrograms/mg to 129.8 +/- 12.9 micrograms/mg by 21 days. Light microscopy revealed that much of the calcium deposition was associated with elastin. Calcification was significantly inhibited in the 4 x 10(-3) mol/l and 4 x 10(-4) mol/l APDP preincubated groups was observed (Ca2+ = 0.70 +/- 0.15 micrograms/mg, 36.6 +/- 19.8 micrograms/mg, respectively versus 117.2 +/- 24.3 micrograms/mg, control). Inhibition of calcification in the groups preincubated in the two most concentrated AlCl3 solutions (Ca2+ = 13.9 +/- 4.9 micrograms/mg [10(-2) mol/l AlCl3], 36.6 +/- 7.1 micrograms/mg [10(-3) mol/l AlCl3], 171.0 +/- 13.2 micrograms/mg [control]) was also demonstrated. No adverse effects of either pretreatment, APDP, or AlCl3 were noted on bone or overall somatic growth.     

Polyester vascular prostheses coated with a cyclodextrin polymer and activated with antibiotics: cytotoxicity and microbiological evaluation

Polyester (PET) vascular grafts are used to replace or bypass damaged arteries. To minimize the risk of infection during and after surgical interventions, a PET vascular prosthesis (Polythese) was functionalized with cyclodextrin polymers (PolyCDs) in order to obtain the controlled release of antibiotics (ABs: ciprofloxacin, vancomcyin and rifampicin). An epithelial cell line (L132) was used to determine the viability of the antibiotics, and human pulmonary microvascular endothelial cells (HPMEC) were used for cell proliferation by cell counting and cell vitality with Alamar Blue fluorescent dye. Staphylococcus aureus, Escherichia coli and Enteroccocus sp. were used to determine the antimicrobial activity of AB-loaded virgin and PolyCD-grafted Polythese by the minimum inhibitory concentration method. The spectrophotometric titration results first showed that a larger amount of ABs was sorbed onto PolyCD-coated Polythese compared to virgin Polythese (26.7 vs. 35.3 mg g(-1), 51.1 vs. 72.4 mg g(-1) and 4.1 vs. 21.0 mg g(-1), respectively, for rifampicin, vancomycin and ciprofloxacin). These results were further confirmed by a microbiological test, which showed AB-loaded PolyCD-coated Polythese displayed better antimicrobial activity. The viability test revealed the toxicity of rifampicin (22 mg l(-1)) and ciprofloxacin (35 mg l(-1)), and the absence of toxicity of vancomycin. These tests allow us to further explain the lower vitality and proliferation of HPMEC on the AB-loaded PolyCD-coated Polythese, which was due not to the functionalization process of prostheses but to the cytotoxicity of certain ABs themselves. Moreover, such a property could be exploited to tackle intracellular bacteria, such as in tuberculosis and other diseases, and will not compromise further in vivo applications of our functionalized vascular prostheses.     

Bacteriological examination of milk and milk products sold in Harare

A study to assess the bacteriological quality of milk and ice cream was conducted using the direct plate count method and the methylene blue dye reduction test. A total of 105 milk and 95 ice cream samples were obtained form two factories (depots) and distributing supermarkets (outlets) in Harare. Under the methylene blue test, all milk and ice cream samples passed the hour and 2 hour tests respectively. However, 99% of the milk and 69% of the ice cream samples reduced the dye after 5.5 and 4 hrs respectively. The results from the direct plate counts revealed the presence of both pathogens and non-pathogens. The median plate counts in the milk and ice cream were found 400 cfu / ml and 100 cfu / ml respectively. Organisms isolated in both samples and in all outlets were similar, these included Bacillus spp. Coagulase Staphlococcus spp., microcuccus spp., Steptococcus spp., Diphthroids, Fusiform bacterial Klebsiella spp., and Citrobacter spp. No significant differences were found in the plate counts of the samples obtained from the depots and outlets for the milk (P = 0.542, df = 1)) and ice cream samples (P = 0.377, df = 1). Results further revealed that there was no significant difference in isolates obtained form strawberry ice cream (0.0096). The study has therefore, revealed that milk and milk product sold in various outlets in Harare contained a variety of bacteria of public health importance and also that the methylene blue dye reduction test is not reliable for the detection of bacterial contaminants in dairy products. It is thus suggested that the use of methylene blue dyes be adapted in combination with other tests such as the plate count in assessing bacterial contaminants in milk products.     

Oxidative stress after three different intensities of running.

In 8 trained subjects (T) and 9 untrained subjects (UT), lipid peroxidation (LPO), total antioxidant capacity (TRAP), superoxide dismutase, catalase, and glutathione peroxidase (GPx) activities were measured in the blood before and after three different intensities of exercise on the treadmill, determined from ventilatory threshold and maximal oxygen uptake data, obtained from a maximal aerobic power test. In plasma, LPO decreased from 3589 +/- 193 to 3274 +/- 223 cps x mg Hb(-1) (p < 0.05), and TRAP increased from 304 +/- 45 to 384 +/- 57 micromol x L(-1) trolox (p < 0.05) after high intensity exercise in T. GPx activity increased in the T group as compared to the UT group, after exercise in moderate (25.90 +/- 3.79 to 15.05 +/- 3.23 nM x min(-1) x mg protein(-1)) and high (21.75 +/- 4.91 to 12.1 +/- 2.46 nM x min(-1) x mg protein(-1)) intensities (p < 0.05). Superoxide dismutase activity increased after exercise at low (8.35 +/- 0.85 to 9.23 +/- 1.03 U SOD x mg protein(-1)) and moderate (8.89 +/- 0.98 to 10.44 +/- 0.86 U SOD x mg protein(-1)) intensity in UT (p < 0.05). There were no changes in catalase activity. These findings indicate that exercise in this model did not increase lipid peroxidation, probably because of the alterations in TRAP and enzymatic antioxidants.     

Characterization of metal-resistant plant-growth promoting Bacillus weihenstephanensis isolated from serpentine soil in Portugal

A metal-resistant bacterial strain SM3 isolated from a serpentine soil in the north-east of Portugal was characterized as Bacillus weihenstephanensis based on the morphological and biochemical characteristics and on the comparative analysis of the partial 16S ribosomal DNA sequence. Bacillus weihenstephanensis SM3 showed a high degree of resistance to nickel (1500 mg l(-1)), copper (500 mg l(-1)) and zinc (700 mg l(-1)) and also to antibiotics (ampicillin, penicillin, kanamycin and streptomycin). Strain SM3 has also exhibited the capability of solubilizing phosphate and producing indole-3-acetic acid (IAA) both in the absence and in the presence of metals (Ni, Cu and Zn). A pot experiment was conducted to elucidate the effects of strain SM3 on plant growth and uptake of Ni, Cu or Zn by Helianthus annuus. Inoculation with strain SM3 increased the shoot and root biomass of H. annuus grown in both non-contaminated and contaminated soil. Furthermore, strain SM3 increased the accumulation of Cu and Zn in the root and shoot systems. A batch experiment was also conducted to assess the metal mobilization potential of strain SM3 in soil. Inoculation with this strain increased the concentrations of water soluble Ni, Cu and Zn in soil. Metal solubilization by this bacterial strain may be an important process to promote the uptake of heavy metals by plants. This study elucidates the multifarious role of strain SM3 in plant growth promotion and its metal mobilizing potential.     

Antifungal activity of a new triazole, voriconazole (UK-109,496), compared with three other antifungal agents tested against clinical isolates of filamentous fungi.

Voriconazole is a new triazole antifungal agent with potent activity against yeast and moulds. We investigated the in vitro activity of voriconazole, itraconazole, amphotericin B and 5-flucytosine against 51 clinical isolates of filamentous fungi. Overall, voriconazole was active (MIC50, 0.5 mg l(-1) and MIC90, 8 mg l(-1)) against these mould isolates. Voriconazole was most active against P. boydii (MIC50, 0.12 mg l(-1)) and Aspergillus spp. (MIC90, 0.5 mg l(-1)) and least active against Fusarium spp. (MIC90, 8 mg l(-1)) and Rhizopus spp. (MIC50, 8 mg l(-1)). Voriconazole was more active than amphotericin B against Aspergillus spp. and P. boydii. By comparison with itraconazole, voriconazole was more active against all isolates except Rhizopus spp. Based on these results, voriconazole has promising activity against commonly encountered isolates of filamentous fungi and its clinical usefulness should be established by further studies.     

A prospective,randomized, placebo-controlled study of the dose effect of oral estradiol on bone mineral density in postmenopausal Chinese women

OBJECTIVES: One of the long-term consequences of estrogen deficiency in postmenopausal women is an increased risk of osteoporosis. Fractures of the hip and lumbar spine are associated with considerable morbidity and mortality. Estrogen replacement therapy reduces the risk of osteoporosis, but there is no clear agreement on the most appropriate doses to be used. The aim of this study was to compare changes in bone mineral density (BMD) measurements using conventional and lower dose estradiol. METHODS: A prospective, randomized, placebo-controlled 12-month study of the effect of 1 and 2 mg estradiol on BMD in 152 hysterectomized postmenopausal Chinese women with no contraindication to the use of estrogen replacement therapy. RESULTS: Over 12 months, spinal BMD in placebo treated patients decreased by a mean of 2% from baseline (-0.02+/-0.03 g/cm(2)) while it increased by 2% in the 1 mg (0.02+/-0.03 g/cm(2)) and 3% in the 2 mg group (0.03+/-0.03 g/cm(2)). Mean changes in BMD over 12 months in the hip were -0.02+/-0.02 g/cm(2) (-2%), 0.01+/-0.02 g/cm(2) (+1%) and 0.01+/-0.03 g/cm(2) (+1%) in the placebo, 1 and 2 mg estradiol groups, respectively (P<0.05). Relative to placebo, increases in BMD in both 1 and 2 mg groups were statistically significant for both spine and hip (P<0.05). However, there was no significant difference in the increase in BMD between the 1 and 2 mg doses for either lumbar spine or hip (P=0.82, 0.53, respectively). CONCLUSION: The results of our study show that a 1 mg dose of oral estradiol is effective in preventing bone loss in postmenopausal Chinese women.