共查询到20条相似文献,搜索用时 31 毫秒
1.
Serpentine soils of Andaman Islands, India characteristically contain high levels of nickel, cobalt and chromium and are colonized by indigenous nickel-hyperaccumulating plants. Attempts have been made to isolate and characterize nickel-resistant microorganisms from these hitherto unexplored naturally nickel-percolated soils. The majority of the nickel-resistant organisms showed a minimum inhibitory concentration (MIC) of Ni 2+ ranging from 300 to 400 mg/l and about 3.4% of the total 89 isolates representing bacterial strains were able to grow at 400 mg/l Ni 2+. The potent Ni 2+-resistant strains AND305 and AND603 were tentatively identified as Pseudomonas spp. and strain AND408 as Bacillus sp. following detailed analysis of morphological and physio-biochemical characteristics. Growth kinetics of these Ni 2+-resistant bacteria showed a prolonged lag phase in Ni 2+-containing media, which extended with increasing nickel concentration. In addition to Ni 2+, these isolates were also resistant to Co 2+, Cd 2+, Cr 6+, Fe 3+, Cu 2+, Mg 2+, Mn 2+(50–200 mg/l) and Hg 2+ (0.5–2.0 mg/l) and the multiple metal-resistance of the isolates were also associated with the resistance to antibiotics ampicillin, cycloserine and penicillin G. 相似文献
2.
Stem and petiole explants, obtained from mature trees, of Albizzia lebbeck, Cassia fistula and C. siamea callused and differentiated shoot-buds and later shoots on B5 medium supplemented with either 0.5 mg/l IAA + 1 mg/l BAP or BM + 2 mg/l NAA + 0.5 mg/l BAP. The stem explants were more responsive than the petiole explants. In A. lebbeck, the IAA substituted medium favoured differentiation from both types of explants. However, in C. fistula, the type of explants rather than the medium composition had an overriding influence on shoot differentiation since those from petiole hardly responded in either medium. It has been possible to obtain plantlets from both A. lebbeck and C. fistula under conditions conducive to rooting. Plantlets of A. lebbeck have also been successfully transferred to the field. 相似文献
3.
A protocol to obtain regenerated plants from protoplasts of Solanum torvum Sw a wild species of eggplant resistant to Verticillium wilt is reported. Leaf protoplasts were enzymatically isolated from six-week old seedlings grown in a controlled environment chamber. Protoplasts were plated on modified KM medium (0.4 M glucose)+(mg/l): 1.0 p-chlorophenoxyacetic acid (CPA)+1.0 naphthaleneacetic acid (NAA)+0.5 6-benzylaminopurine (BAP) and 0.02 abscisic acid (ABA). The protoplast density was 5×10 4 per ml with 5 ml placed in each of two quadrants in X-dishes (100×15 mm). The reservoir medium was modified KM+(mg/l): 0.1 NAA+0.5 BAP+0.1 M sucrose+0.1 M mannitol+0.6% washed agar+1% activated charcoal. Dishes were initially placed in the dark at 27°C. Protoplast division was initiated in 1–2 weeks and 4 weeks later p-calli were 1–3 mm. Plating efficiency was 11% when measured at 3 weeks. Six-week old p-calli were transferred individually onto Whatman No. 1 filter paper layered on modified KM (0.15 M sucrose)+mg/l: 2.0 indoleacetic acid (IAA)+2.0 zeatin+0.5% washed agar for 2 weeks. Subsequently, shoots occurred within 4 weeks at 70% efficiency on MS+30 g/l sucrose+2 mg/l zeatin. Shoots were rooted on half strength MS+10 g/l sucrose.Abbreviations ABA
abscisic acid
- BAP
6-benzylaminopurine
- CPA
p-chlorophenoxyacetic acid
- IAA
indoleacetic acid
- KM
Kao and Michayluk
- MS
Murashige and Skoog
- NAA
naphthaleneacetic acid
- 2ip
6-dimethylallyamino purine
Michigan Agricultural Experiment Station Journal Article No. 12167 相似文献
4.
The present work deals with the biosorption performance of dried and non-growing biomasses of Exiguobacterium sp. ZM-2, isolated from soil contaminated with tannery effluents, for the removal of Cd 2+, Ni 2+, Cu 2+, and Zn 2+ from aqueous solution. The metal concentrations studied were 25 mg/l, 50 mg/l, 100 mg/l, 150 mg/l and 200 mg/l. The effect of solution pH and contact time was also studied. The biosorption capacity was significantly altered by pH of the solution. The removal of metal ions was conspicuously rapid; most of the total sorption occurred within 30 min. The sorption data have been analyzed and fitted to the Langmuir and Freundlich isotherm models. The highest Q max value was found for the biosorption of Cd 2+ at 43.5 mg/g in the presence of the non-growing biomass. Recovery of metals (Cd 2+, Zn 2+, Cu 2+ and Ni 2+) was found to be better when dried biomass was used in comparison to non-growing biomass. Metal removal through bioaccumulation was determined by growing the bacterial strain in nutrient broth amended with different concentrations of metal ions. This multi-metal resistant isolate could be employed for the removal of heavy metals from spent industrial effluents before discharging them into the environment. 相似文献
5.
Heavy metal contamination of the environment is a serious concern because of their deleterious effects on biological systems. To the best of our knowledge, this is the first investigation on isolation of heavy metal resistant bacteria from contaminated sites of glass industrial area. The study focused on isolation and characterization of Ni2+ resistant bacteria from these sites and analysis of their Ni2+ accumulation potential. Out of 38 different bacterial isolates 3 bacteria were able to tolerate up to 24 mM Ni2+ concentration. These bacterial strains were identified as E. coli (AS17b), Escherichia coli (AS21) and Microbacterium sp. (AS33) by 16S rRNA (16S ribosomal RNA) sequencing and their basic local alignment search tool search analysis. Growing cell of E. coli and Microbacterium sp. revealed accumulation of 0.12, 0.08 and 0.06 µg, of Ni2+/mg dry weight of cells, respectively, by 72 hr. Similarly resting cell of these strains showed accumulation of 0.27, 0.11 and 0.08 µg of Ni2+/mg dry weight of cells by 150 min, respectively. These results reveal that strain E. coli (AS21) shows maximum accumulation efficiency for Ni2+ among different isolates studied under shaking as well as starving conditions. Hence, E. coli (AS21) could serve as an efficient and promising bacterium for bioremediation of nickel-contaminated sites. 相似文献
6.
In this study, four bacterial species isolated from an industrially polluted region at the Istanbul–Kocaeli border were characterized and their efficiencies for bioremoval of Cu 2+, Ni 2+, Cr 3+, Zn 2+, and Fe 2+ were determined in batch and continuous systems. Strain N4c was used for continuous metal bioremoval in a packed-bed immobilized cell reactor (ICR) with a working volume of 180 ml. ICR was successfully operated for treatment of synthetic wastewater containing 200 mg/l Cu 2+ and Ni 2+ for 140 and 80 h, respectively. Bioremoval efficiency of ICR for Cu 2+ reached around 90 % in the last 3 days of operation at a flow rate of 1 ml/min. Ni 2+ bioremoval in ICR was less efficient as the system worked for only 80 h and bioremoval efficiency decreased from 73.3 to 42.8 % during the operation period. Wastewater containing one or two types of metal seems to be a good candidate for treatment with immobilized N4c cells in a continuous system. Survival of the cells in the wastewater was found to be an important parameter affecting bioremoval efficiency in both batch and continuous systems. The ICR used in this study can be scaled up for treatment of industrial wastewaters containing Ni 2+ or Cu 2+. 相似文献
7.
Summary An Enterobacter species, isolated from electroplating effluent, could remove significant amount of nickel ion (Ni 2+) from growth medium and sewage effluent. In order to construct a bioreactor to remove Ni 2+ from electroplating effluent, bacterial cells were immobilized in polyacrylamide beads. The highest removal capacity (RC, mg of Ni 2+/g of dry cells) and removal efficiency (RE, % of added Ni 2+ removed by bacterial cells) of Ni 2+ of immobilized bacterial cells were obtained by optimizing the growth conditions for the bacterial cells such as the composition of the growth medium, incubation time and incubation temperature; and the operational parameters of the bioreactor such as retention time and pH of the Ni 2+ containing solution, respectively. 相似文献
8.
We report the effects of tetracycline analogues on cytosolic Ca 2+ transients resulting from application of ionic nickel (Ni 2+), a potent surrogate agonist of the osteoclast Ca 2+ receptor. Preincubation with minocycline (1 mg/l) or a chemically modified tetracycline, 4-dedimethyl-aminotetracycline (CMT-1) (1 or 10 mg/l), resulted in a significant attenuation of the magnitude of the cytosolic [Ca 2+] response to an application of 5 mM-[Ni 2+]. Preincubation with doxycycline (1 or 10 mg/l) failed to produce similar results. In addition, application of minocycline alone (0.1–100 mg/l) resulted in a 3.5-fold elevation of cytosolic [Ca 2+]. The results suggest a novel action of tetracyclines on the osteoclast Ca 2+ receptor. 相似文献
9.
Bioaccumulation and heavy metal resistance of Cd 2+, Cu 2+, Ni 2+, Zn 2+ and Mn 2+ ions by thermophilic Geobacillus toebii subsp. decanicus and Geobacillus thermoleovorans subsp. stromboliensis were investigated. The metal resistance from the most resistant to the most sensitive was found as Mn > Ni > Cu > Zn > Cd
for both Geobacillus thermoleovorans subsp . stromboliensis and Geobacillus toebii subsp. decanicus. It was determined that the highest metal bioaccumulation was performed by Geobacillus toebii subsp. decanicus for Zn (36,496 μg/g dry weight cell), and the lowest metal bioaccumulation was performed by Geobacillus toebii subsp. decanicus for Ni (660.3 μg/g dry weight cell). Moreover, the dead cells were found to biosorbe more metal in their membranes compared
to the live cells. In the presence of 7.32 mg/l Cd concentration, the levels of Cd absorbed in live and dead cell membranes
were found as 17.44 and 46.2 mg/g membrane, respectively. 相似文献
10.
Shoot-tip explants of Rheum emodi Wall. (Polygonaceae) gave rise to multiple shoots when cultured on a Murashige and Skoog (1962) medium (MS) with 2.0 mg/l 6-benzylaminopurine (BAP) and 1.0 mg/l indole-3-butyric acid (IBA). Also, shoot buds developed from leaf explants using MS medium with 2.0 mg/l BAP and 0.25 to 1.0 mg/l indole-3-acetic acid (IAA) or IBA. Roots were induced when the resulting shoots were placed on MS medium with 1.0 mg/l IBA. Both regeneration procedures gave rise to healthy plantlets that were established in soil under glasshouse conditions at 80% frequency after hardening phase of two weeks. Regenerated plants showed a constant chromosome number of 2n= 2x=22, same as the parent plant. The use of liquid shake cultures minimized the time and culture medium requirements for propagation. This procedure can be applied for the conservation and utilization of elite clones of R. emodi.Abbreviations BAP
6-benzylaminopurine
- Dd H 2O
Double glass distilled water
- IAA
indole-3-acetic acid
- IBA
indole-3-butyric acid
- K
Kinetin
- MS
Murashige and Skoog's (1962) medium
- RH
Relative humidity
CIMAP Publication No. 876 相似文献
11.
Nutrient and heavy metal pollutions are major concern worldwide. This study aimed at comparing the effect of Ni 2+ on nutrient removal efficiency of four indigenous wastewater protozoan species ( Aspidisca sp., Paramecium sp., Peranema sp., Trachelophyllum sp.). Specific physicochemical parameters and microbial growth/die-off were measured using standard methods. The results revealed that protozoan species were able to simultaneously remove phosphate, nitrate and Ni 2+ at concentrations ranging between 66.4–99.36%, 56.19–99.88% and 45.98–85.69%, respectively. Peranema sp. appeared to be the isolates with the highest removal of nutrients (Phosphate-99.36% and Nitrate-99.88%) while Paramecium sp. showed higher removal of Ni 2+ at 85.69% and low removal of nutrients. Aspidisca sp. was the most sensitive isolate to Ni 2+ but with significant nutrient removal (Phosphate-66.4% and Nitrate-56.19%) at 10 mg-N 2+/L followed by an inhibition of nutrient removal at Ni 2+ concentration greater than 10 mg/L. Significant correlation between the growth rate and nutrient removal ( r = 0.806/0.799, p < 0.05 for phosphate and nitrate, respectively) was noted. Except for Peranema sp. which revealed better nutrient removal ability at 10 mg-Ni 2+/L, an increase in Ni 2+ concentration had a significant effect on nutrient removal efficiency of these indigenous protozoan species . This study suggests that although Ni 2+ appeared to be toxic to microbial isolates, its effect at a low concentration (10 mg-Ni 2+/L) towards these isolates can be used to enhance the wastewater treatment process for the removal of nutrients. Peranema sp., which was able to remove both Ni 2+ and nutrients from wastewater mixed-liquor, can also be used for bioremediation of wastewater systems. 相似文献
13.
Axillary buds from 5 genotypes of mulberry belonging to 4 species were cultured on modified MS basal medium. A total of 30 media combinations were tried for all the genotypes. The response of axillary buds and the requirement for growth regulators varied with genotype. In Morus indica BAP (0.25–0.5 mg/l), and in M. alba and M. rotondifolia GA 3 (0.5–1.0 mg/l)were found to induce sprouting. Two genotypes of M. bombycis, namely Schimanochi and Mizusawa, developed healthy shoots on the incorporation of 2,4-D (0.5–1.0 mg/l) and BAP (0.5–2.0 mg/l), respectively. IBA (0.5 mg/l), along with cytokinin/auxin/gibberellin, had no effect on bud growth but helped root induction. Shoots developed from the axillary buds were further multiplied as nodal explants. MS basal medium supplemented with 0.5 mg/l IBA and LS vitamins was found best to produce healthy plantlets in all the genotypes. An average 89% survival was observed on transferring the plantlets to soil.Abbreviations MS
Murashige and Skoog (1962)
- LS
Linsmaier and Skoog (1965)
- IBA
3-indole-butyric acid
- GA 3
Gibberellic acid
- BAP
6-Benzylaminopurine
- Kn
Kinetin
- 2,4-D
2,4-Dichlorophenoxyacetic acid 相似文献
14.
Anthers of Albizzia lebbeck on B 5 medium (BM) supplemented with kinetin (2 mg/l) and 2, 4-D (0.5 mg/l) showed callus initiation from microspores. Differentiation of embryoids and shoots was obtained on BM + BAP (1 mg/l) + IAA (0.5 mg/l) and of roots on BM. Root tip squashes of the regenerated plantlets showed the haploid chromosome number (n=13), confirming the microspore origin of the regenerants. 相似文献
15.
Biosorptions of Pb 2+, Cr 6+, Cd 2+ and Ni 2+ were investigated, with special emphasis on the first one, using live and dead fungal mycelia. Of the four fungi, namely Polyporus ostreiformis, Volvariella volvacea, Pleurotus sajor-caju and Phanerochaete chrysosporium, the last one was found to be most effective in Pb 2+ removal. Total biosorption was effected in 6 days up to the Pb 2+ concentration of 6 mg/l, with a specific uptake of 1.33 mg Pb 2+/g dry cell mass. The removal of other three metals varied between 28.8–73.3% from a medium containing 4 mg/l of each of the metals.Laboratory facilities created under M.Tech programme in Biotechnology and Engineering (sponsored by Department of Biotechnology, Govt. of India) were partly utilized for this study. 相似文献
16.
Uptake of Co 2+ by three nickel-resistant strains (Ni R1, Ni R2, and Ni R3) of Neurospora crassa that differed in resistance to Co 2+ has been studied. Uptake was linear with Co 2+ concentration (up to 1 m M), with time (up to 6 h), and with pH between 3 and 6. Uptake rates were in the order Ni R2>Ni R1>Ni R3. In all strains, there was gradual increase in Co 2+ uptake between 10° and 28°C, with a much sharper increase between 28° and 40°C. Metabolic inhibitors decreased Co 2+ uptake partially in all strains, except for KF in Ni R3. About 50–80 g Co 2+/100 mg dry weight was surface bound. Ni 2+, Zn 2+, and Mn 2+ competed with Co 2+, the effects being strain specific. Mg 2+ inhibited Co 2+ uptake in all strains with preformed mycelia. In Ni R1 and Ni R2 only with young mycelia (40 h old) was Mg 2+ inhibitory to Co 2+ uptake, during growth in the presence of Co 2+. The results suggested the presence of two transport systems for Co 2+ in Ni R1 and Ni R2, only one of which was sensitive to Mg 2+; in contrast, Ni R3 had a single system, which was sensitive to Mg 2+. 相似文献
17.
Hafnia alvei 5-5, isolated from a soil-litter mixture underneath the canopy of the nickel-hyperaccumulating tree Sebertia acuminata (Sapotaceae) in New Caledonia, was found to be resistant to 30 mM Ni 2+ or 2 mM Co 2+. The 70-kb plasmid, pEJH 501, was transferred by conjugation to Escherichia coli, Serratia marcescens, and Klebsiella oxytoca. Transconjugant strains expressed inducible nickel resistance to between 5 and 17 mM Ni 2+, and cobalt resistance to 2 mM Co 2+. A 4.8-kb Sal– EcoRI fragment containing the nickel resistance determinant was subcloned, and the hybrid plasmid was found to confer a moderate
level of resistance to nickel (7 mM Ni 2+) even to E. coli. The expression of nickel resistance was inducible by exposure to nickel chloride at a concentration as low as 0.5 mM Ni 2+. By random Tn phoA′-1 insertion mutagenesis, the fragment was shown to have structural genes as well as regulatory regions for nickel resistance.
Southern hybridization studies showed that the nickel-resistance determinant from pEJH501 of H. alvei 5-5 was homologous to that of pTOM9 from Alcaligenes xylosoxydans 31A.
Electronic Publication 相似文献
18.
The photosynthetic sulfur bacterium, Chromatium
vinosum, was cultured in inorganic photographic processing solutions containing silver thiosulfate complex salt (AgNa 3(S 2O 3) 2) under light. It was found that Chromatium was resistant to Ag and accumulated granular silver in the membrane during growth. The amount of Ag accumulated in the cells depended on the initial concentrations of the Ag salt in the culture solution. When the concentration of Ag was 300 mg/l, the bacteria accumulated Ag as high as 30% of the dry cell weight. The size of the granules was 0.1 to 0.3 m. Results from X-ray microanalysis indicated that these granules consisted mostly of Ag o with small fractions of Ag 2S and AgCl. 相似文献
19.
Arginine vasopressin binding sites on rat brain membranes were solubilized and purified by affinity chromatography. Membrane protein solubilized with CHAPS bound arginine vasopressin (AVP) only in the presence of divalent cations. Specific binding to the solubilized tissue was maximally stimulated by Ni 2+, and markedly stimulated by Co 2+ (30% of maximal binding with Ni 2+), Zn 2+ (18%), and Fe 2+ (11%), parallel to the effects of these ions on the binding of AVP to neural membranes. Binding to solubilized tissue was not stimulated by Mg 2+, Cu 2+, Mn 2+, or Ca 2+. In the presence of Ni 2+, binding of AVP to solubilized tissue was reversible, and the dissociation constant (10.5 nM), pH optimum, and time course were virtually identical to those of the membrane-bound AVP binding site. Purification of solubilized AVP-binding proteins by affinity chromatography on AVP-sepharose followed by gel electrophoresis yielded a major band of 55 kdalton molecular weight when purified in the presence of 5 mM Mg 2+, or a major band of 62 kdaltons when purified in the presence of 1–5 mM Ni 2+ or 10 M Zn 2+. By means of a new binding assay involving conjugation of the 62 kdalton fraction to brain membranes, the extent of purification of AVP binding activity was 150-fold in the presence of Ni 2+. We suggest that the 62 kdalton protein is a component of the Ni-stimulated AVP binding site. 相似文献
20.
Plantlets regenerated from shoot apices, cotyledons and callus cultures in Moth bean, Vigna aconitifolia (JACQ) Marechal, a drought resistant legume and pulse crop, were rooted and transferred to soil. Explants for these studies were derived from seedlings pre-conditioned by germination of seeds on B5BA and WMB (control).Abbreviations MS
Murashige and Skoog (1962)
- B5
B5 basal medium (Gamborg et al 1968)
- B5BA
B5 basal medium containing BA (2.25 mg/l)
- WMB
Modified White's medium (Mascarenhas et al 1976)
- BA
6-benzyladenine
- IAA
indole-3-acetic acid
- NAA
1-napthaleneaceticacid
- 2,4-D
2,4-dichlorophenoxyacetic acid
- IBA
indolebutyric acid
- 2iP
N( –2 isopentyl) adenine
- CM
coconut milk
NCL Communication No. 3375 相似文献
|