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1.
Guven Ozdemir Baris Pazarbasi Ali Kocyigit Esra Ersoy Omeroglu Ihsan Yasa Ismail Karaboz 《World journal of microbiology & biotechnology》2008,24(8):1375-1381
The present study deals with the decolorization of Acid Black 210 by a bioluminescent bacterium, Vibrio harveyi TEMS1, isolated from coastal seawater of Izmir Bay, Turkey. Maximum rate of decolorization of Acid Black 210 was observed
when Luria Bertani medium was used. Decolorization of Acid Black 210 was 38.9% and 93.9% at 24 h under shaking and static
conditions, respectively. The optimum dye-decolorizing activity of the culture was obtained at 100 ppm initial dye concentration
and incubation temperature of 20°C. Vibrio harveyi TEMS1 was also tested for its ability to decolorize four azo dyes (Acid Black 24, Acid Blue 7, Acid Green 20, Acid Yellow
36) in addition to Acid Black 210. 相似文献
2.
Ola M. Gomaa John E. Linz C. A. Reddy 《World journal of microbiology & biotechnology》2008,24(10):2349-2356
Synthetic textile dyes are among the most dangerous chemical pollutants released in industrial wastewater streams. Recognizing
the importance of reducing the environmental impact of these dyes, the ability of the white rot fungus Phanerochaete chrysosporium to decolorize various textile dyes was investigated. This fungus decolorized 6 of the 14 structurally diverse dyes with varying
efficiency (between 14% and 52%). There was no discernable pattern of decolorization even among dyes of the same chemical
class, suggesting that attack on the dyes is relatively non-specific. Among the three dyes which showed >40% decolorization,
Victoria Blue B (VB) was chosen for further analysis because the ability of the fungus to decolorize VB was nearly independent
over a relatively broad concentration range. Blocking lignin peroxidase (LiP) and manganese peroxidase (MnP) production by
the fungus did not substantially affect VB decolorization. Inhibition of laccase production by adding various inhibitors to
shaken cultures reduced VB decolorization significantly suggesting a role for laccase in VB decolorization. When sodium azide
and aminotriazole were used to inhibit endogenous catalase and cytochrome P-450 oxygenase activities, there was 100% and 70%
reduction in VB decolorization, respectively. Adding benzoate to trap hydrogen peroxide-derived hydroxyl radicals resulted
in 50% decolorization of VB. Boiling the extracellular fluid (ECF) for 30 min resulted in approximately 50% reduction in VB
decolorization. Collectively, these data suggest that laccase, and/or oxygenase/oxidase and a heat-stable non-enzymatic factor,
but not Lip and MnP, play a role in VB decolorization by P. chrysosporium. 相似文献
3.
Lamia Ayed Kamel Chaieb Abdelkarim Cheref Amina Bakhrouf 《World journal of microbiology & biotechnology》2009,25(4):705-711
Triphenylmethane dyes belong to the most important group of synthetic colorants and are used extensively in the textile industries
for dying cotton, wool, silk, nylon, etc. They are generally considered as the xenobiotic compounds, which are very recalcitrant
to biodegradation. Sphingomonas paucimobilis, was isolated from the soil sample collected from contaminated sites of textile industry located in KsarHellal, Tunisia,
and it was able to decolorize Malachite Green (MG) dye (50 mg/l) within 4 h under shaking condition (pH 9 and temperature
25°C). The effect of inoculum size, dye concentration, temperature and initial pH of the solution were studied. The results
obtained from the batch experiments revealed the ability of the tested bacteria to remove dye. UV–Vis spectroscopy and FTIR
analysis of samples before and after decolorization confirmed the ability of the tested strain to decolorize MG. In addition,
the phytotoxicity study revealed the degradation of MG into non-toxic product by S. paucimobilis. 相似文献
4.
Decolorization of a dye industry effluent by <Emphasis Type="Italic">Aspergillus fumigatus</Emphasis> XC6 总被引:1,自引:0,他引:1
The strain Aspergillus fumigatus XC6 isolated from mildewing rice straw was evaluated for its ability to decolorize a dye industry effluent. The strain was
capable of decolorizing dyes effluent over a pH range 3.0–8.0 with the dyes as sole carbon and nitrogen sources. The optimum
pH was 3.0; however, supplemented with either appropriate nitrogen sources (0.2% NH4Cl or (NH4)2SO4 ) or carbon sources (1.0% sucrose or potato starch), the strain decolorized the effluent completely at the original pH of
the dyes effluent. Therefore, A. fumigatus XC6 is an efficient strain for the decolorization of reactive textile dyes effluents, and it might be a practical alternative
in dyeing wastewater treatment. 相似文献
5.
In this study, the cellulase gene celD from Clostridium thermocellum was cloned into expression vectors pET-20b(+) and pHsh. While high expression can be achieved by means of both these expression
systems, only the pHsh expression system gives soluble proteins. By weakening the mRNA secondary structure and replacing the
rare codons for the N-terminal amino acids of the target protein, the expression level of CelD was increased from 4.1 ± 0.3 to 6.4 ± 0.4 U ml−1 in LB medium. Recombinant CelD was purified by heat treatment followed by Ni–NTA affinity. The purified CelD exhibited the
highest activity at pH 5.4 and 60°C, and retained more than 50% activity after incubation at 70°C for 1 h. The cellulase activity
of CelD was significantly enhanced by Ca2+ but inhibited by EDTA. The favorable properties of CelD offer the potential for genetic modification of strains for biomass
degradation. Presently, one of the major bottlenecks for industrial cellulase users is the high cost of enzyme production.
The high level expression of soluble enzymes from the pHsh expression system offers a novel approach for the production of
cellulases to be used in various agro-industrial processes such as chemical, food and textile. 相似文献
6.
Xin Zhou Zhengping Zhang Xiaohe Jia Yifan Wu Lan Luo Zhimin Yin 《World journal of microbiology & biotechnology》2008,24(8):1267-1272
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. 相似文献
7.
The purpose of the present study was to determine the inhibitory activities of two bacteriocins, produced by lactobacilli,
against genital mycoplasmas. In this study, infections produced by genital mycoplasmas were studied; of these, 1.3% were caused
by Mycoplasma hominis, 10.7% by Ureaplasma urealyticum and 5.6% by U. urealyticum + M. hominis. U. urealyticum was isolated from 75 out of 123 patients with genital mycoplasmas, while M. hominis was isolated from 9 patients (7.3%) and both U. urealyticum and M. hominis from 39 patients (31.7%). Bacteriocins, L23 and L60, produced by Lactobacillus fermentum and L. rhamnosus, respectively, appear to be two novel inhibitors of bacterial infection with potential antibacterial activity. Both bacteriocins
proved to be active against 100% of strains tested; MICs of bacteriocin L23 ranged between 320 and 160 UA ml−1 for 78% of the M. hominis strains and between 320 and 80 UA ml−1 for 95% of the U. urealyticum strains. In addition, bacteriocin L60 was still active at 160 UA ml−1 for a high percentage (56%) of M. hominis strains, and at 80 UA ml−1 for 53% of the U. urealyticum strains. Interestingly, these antimicrobial substances produced by lactobacilli showed an inhibitory activity against genital
mycoplasmas even when diluted. Altogether, our study indicates that the bacteriocins, L23 and L60, are good candidates for
the treatment or prevention of genital infections in women. 相似文献
8.
Withu Choosri Regina Paukner Petra Wührer Dietmar Haltrich Christian Leitner 《World journal of microbiology & biotechnology》2011,27(6):1349-1353
The gene gaoA encoding the copper-dependent enzyme galactose oxidase (GAO) from Fusarium graminearum PH-1 was cloned and successfully overexpressed in E. coli. Culture conditions for cultivations in shaken flasks were optimized, and optimal conditions were found to be double-strength
LB medium, 0.5% lactose as inducer, and induction at the reduced temperature of 25°C. When using these cultivation conditions ~24 mg
of active GAO could be produced in shaken flasks per litre medium. Addition of copper to the fermentation medium decreased
the enzyme production significantly. The His-tagged recombinant enzyme could be purified conveniently with a single affinity
chromatography step. The purified enzyme showed a single band on SDS–PAGE with an apparent molecular mass of 66 kDa and had
kinetic properties similar to those of the fungal wild-type enzyme. 相似文献
9.
K. Samuel D. Debashish B. Madhumita G. Padmaja Siva Ram Prasad V. Bhaskara Ramana Murthy P. S. Rao 《In vitro cellular & developmental biology. Plant》2009,45(4):466-473
The propagation of Givotia rottleriformis Griff. is difficult as a result of long seed dormancy associated with poor seed germination. The present study was undertaken
to develop a protocol to overcome seed dormancy by culture of zygotic embryo axes and then develop an efficient method for
micropropagation of Givotia. Best germination frequency (78.3%) was achieved from mature zygotic embryo axes isolated from acid-scarified fresh seeds
when cultured on Murashige and Skoog (MS) medium (half-strength major salts) with 28.9 μM gibberellic acid (GA3). Efficient plant conversion was achieved by transfer of 10-d-old germinated embryos to MS medium (half-strength major salts)
supplemented with 1.2 μM kinetin (KN) and 0.5 μM indole-3-butyric acid (IBA). However, acid scarification of 1-yr-old seeds
decreased the germination frequency of zygotic embryo axes in comparison to those obtained from non-acid-scarified seeds which
germinated (96.2%) and converted into plants (80.3%) on MS basal (half-strength major salts) medium. Multiple shoot bud induction
was achieved by culture of shoot tips derived from in vitro germinated seedlings on MS medium with 0.5 μM thidiazuron for 4 wk, and the shoots elongated after transfer to a secondary
medium with 1.2 μM KN. A maximum number of 7.8 shoots per explant with an average shoot length of 3.2 cm was achieved after
two subcultures on this medium. The in vitro regenerated shoots rooted (41.5%) on half-strength MS medium with 0.5 μM IBA. The in vitro generated seedlings and micropropagated plants were established in soil with a survival frequency of 70% and 60%, respectively. 相似文献
10.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献
11.
Decolorization of reactive dyes by <Emphasis Type="Italic">Clostridium bifermentans</Emphasis> SL186 isolated from contaminated soil 总被引:1,自引:0,他引:1
Min-Ho Joe Sang-Young Lim Dong-Ho Kim In-Soo Lee 《World journal of microbiology & biotechnology》2008,24(10):2221-2226
Decolorization of textile reactive azo dyes by a strain of bacteria (SL186) isolated from a contaminated site was investigated.
SL186 was identified as Clostridium bifermentans by phenotypic characterization and 16S rDNA sequence comparison. Under anaerobic conditions, SL186 had decolorized the dyes
Reactive Red 3B-A, Reactive Black 5, and Reactive Yellow 3G-P by over 90% after 36 h post-inoculation. The bacterium retained
decolorizing activity over a wide range of pH values (6–12), with peak activity at pH 10. Additionally, SL186 decolorized
a relatively high concentration of Reactive Red 3B-A dye (1,000 ppm) by over 80% and raw industrial effluent effectively.
The addition of glucose increased the decolorization rate a little. Spectrophotometric analyses of the reactive dyes showed
no distinct peak indicating aromatic amines. However, a new peak was detected between 300 and 450 nm from the decolorized
raw industrial effluent. These results suggest that C. bifermentans SL186 is a suitable bacterium for the biological processing of dye-containing wastewater. 相似文献
12.
Xiaohuan Wang Zhenhua Gao Yunzhen Wang Ray A. Bressan Stephen C. Weller Xia Li 《In vitro cellular & developmental biology. Plant》2009,45(4):435-440
An in vitro regeneration system with a 100% efficiency rate was developed in peppermint [Mentha x piperita] using 5- to 7-mm-long second internode stem segments of 3-wk-old stock plants. Shoots developed at sites of excision on
stem fragments either directly from the cells or via primary calluses. The optimal medium for maximum shoot initiation and
regeneration contained Murashige and Skoog (MS) salts, B5 vitamins, thidiazuron (TDZ, 11.35 μM), ZT (4.54 μM), 10% coconut
water (CW), 20 g l−1 sucrose, 0.75% agar, adjusted to pH 5.8. A frequency of 100% shoot initiation was achieved, with an average of 39 shoots
per explant. This regeneration system is highly reproducible. The regenerated plants developed normally and were phenotypically
similar to Black Mitcham parents. 相似文献
13.
A. Karthikeyan J. Shilpha S. Karutha Pandian M. Ramesh 《Plant Cell, Tissue and Organ Culture》2012,109(1):153-165
A reproducible and highly efficient protocol for Agrobacterium tumefaciens-mediated transformation of indica rice (Oryza sativa L. subsp. indica cv. ADT 43) was established. Prior to transformation, embryogenic callus were induced from mature seeds incubated on Linsmaier
and Skoog (LS) medium supplemented with 2.5 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg l−1 thiamine-HCl. Callus, intact mature seeds, and other in vitro derived explants (leaf bases, leaf blades, coleoptiles, and
root-tips) were immersed in a bacterial suspension culture of A. tumefaciens strain EHA 105, OD600 of 0.8, and co-cultivated on LS medium for 2 days in the dark at 25 ± 2°C. Based on GUS expression
analysis, 10 min incubation time of explants on a co-cultivation medium containing 100 μM acetosyringone was optimum. Following
β-glucuronidase (GUS) assay and polymerase chain reaction (PCR) analysis, transformants were identified. Stable integration
of the transgene was confirmed in four putatively transformed T0 plants by Southern blot analysis. The copy number of the transgene in these lines, one to two, was then determined. Among
the observations made, necrosis of co-cultivated explants was a problem, as well as sensitivity of callus to Agrobacterium infection. Levels of necrosis could be minimized following co-cultivation of explants in a medium consisting of 30% LS and
containing 10 g l−1 (14), polyvinyl pyrrolidone, 10% coconut water, and 250 mg l−1 timentin (15:1). This latter medium also increased the final transformation efficiency to 15.33%. 相似文献
14.
Jyoti P. Jadhav Swapnil S. Phugare Rhishikesh S. Dhanve Shekhar B. Jadhav 《Biodegradation》2010,21(3):453-463
A newly isolated novel bacterium from sediments contaminated with dyestuff was identified as Pseudomonas aeruginosa strain BCH by 16S rRNA gene sequence analysis. The bacterium was extraordinarily active and operative over a wide rage of
temperature (10–60°C) and salinity (5–6%), for decolorization of Direct Orange 39 (Orange TGLL) at optimum pH 7. This strain
was capable of decolorizing Direct Orange 39; 50 mg l−1 within 45 ± 5 min, with 93.06% decolorization, while maximally it could decolorize 1.5 g l−1 of dye within 48 h with 60% decolorization. Analytical studies as, UV–Vis spectroscopy, FTIR, HPLC were employed to confirm
the biodegradation of dye and formation of new metabolites. Induction in the activities of lignin peroxidases, DCIP reductase
as well as tyrosinase was observed, indicating the significant role of these enzymes in biodegradation of Direct Orange 39.
Toxicity studies with Phaseolus mungo and Triticum aestivum revealed the non-toxic nature of degraded metabolites. 相似文献
15.
Qi Zhu Fengtao Wu Feng Ding Dong Ye Yongqin Chen Yi Li Yang Zhifan 《Plant Cell, Tissue and Organ Culture》2009,96(3):317-324
Dioscorea zingiberensis Wright has been cultivated as a pharmaceutical crop for production of diosgenin, a precursor for synthesis of various important
steroid drugs. Because breeding of D. zingiberensis through sexual hybridization is difficult due to its unstable sexuality and differences in timing of flowering in male and
female plants, gene transfer approaches may play a vital role in its genetic improvement. In this study, the Agrobacterium tumefaciens-mediated transformation of D. zingiberensis was investigated with leaves and calli as explants. The results showed that both leaf segments and callus pieces were sensitive
to 30 mg/l hygromycin and 50–60 mg/l kanamycin, and using calli as explants and addition of acetosyringone (AS) in cocultivation
medium were crucial for successful transformation. We first immersed callus explants in A. tumefaciens cells for 30 min and then transferred the explants onto a co-cultivation medium supplemented with 200 μM AS for 3 days. Three
days after, we cultured the infected explants on a selective medium containing 50 mg/l kanamycin and 100 mg/l timentin for
formation of kanamycin-resistant calli. After the kanamycin-resistant calli were produced, we transferred them onto fresh
selective medium for shoot induction. Finally, the kanamycin resistant shoots were rooted and the stable incorporation of
the transgene into the genome of D. zingiberensis plants was confirmed by GUS histochemical assay, PCR and Southern blot analyses. The method reported here can be used to
produce transgenic D. zingiberensis plants in 5 months and the transformation frequency is 24.8% based on the numbers of independent transgenic plants regenerated
from initial infected callus explants. 相似文献
16.
Soil and sediment samples obtained from Orange MR dye contaminated habitat were screened for heterotrophic bacterial population.
The heterotrophic bacterial density of dye-contaminated soil was 2.14 × 106 CFU/g. The generic composition of heterotrophic bacterial population was primarily composed of 10% of Proteus sp., 15% Aeromonas sp., 20% Bacillus sp., 25% Pseudomonas sp. and 30% Micrococcus sp. The bacterial strain that decolorized the azo dye Orange MR up to 900 ppm was identified as Micrococcus sp. The optimum inoculum load, pH and temperature were found to be 5%, 6 and 35°C, respectively. The rate of decolorization
was assessed using spectrophotometer at 530 nm and the percentage of decolorization was ascertained. The autochthonous bacterial
isolate was able to utilize the dye as both nitrogen and carbon source. 相似文献
17.
Basic Violet 3 (BV) belongs to the most important group of synthetic colorants and is used extensively in textile industries.
It is considered as xenobiotic compound which is recalcitrant to biodegradation. As Candida krusei could not use BV as sole carbon source, experiments were conducted to study the effect of cosubstrates on decolorization
of BV in semi synthetic medium using glucose, sucrose, lactose, maltose, yeast extract, peptone, urea and ammonium sulphate.
Maximum decolorization (74%) was observed in media supplemented with sucrose. Use of sugarcane bagasse extract as sole nutrient
source showed 100% decolorization of BV within 24 h under optimized condition. UV–visible, FTIR spectral analysis and HPLC
analysis confirmed the biodegradation of BV. Six degradation products were isolated and identified. We propose the biodegradation
pathway for BV which occurs via stepwise reduction and demethylation process to yield mono-, di-, tri-, tetra-, penta- and
hexa-demethylated BV species which was degraded completely. The study of the enzymes responsible for decolorization showed
the activities of lignin peroxidase, lacasse, tyrosinase, NADH-DCIP reductase, MG reductase and azoreductase in cells before
and after decolorization. A significant increase in activities of NADH-DCIP reductase and laccase was observed in the cells
after decolorization. The yeast C. krusei could show the ability to decolorize the textile dye BV using inexpensive source like sugarcane bagasse extract for decolorization. 相似文献
18.
Heavy-metal chromium [Cr(VI)] is a ubiquitous environmental pollutant. Comparing with chemical reduction, microbiological
reduction is considered to be a friendly and cheaper way to decrease the damage caused by chromate. A bacterial strain, CR-07,
which is resistant to and capable of reducing chromate was isolated from a mud sample of iron ore and identified as a Microbacterium sp. The bacterium had a high degree of tolerance to chromate, and could grow in LB medium containing 4.08 mM of K2Cr2O7. It also had a degree of resistance to other heavy metals, e.g. Cd2+, Pb2+, Zn2+, Cu2+, Co2+, Hg2+ and Ag+. The bacterium could remove 1.02 mM of Cr(VI) from LB medium within 36 h of incubation. Chromate removal was achieved in
the supernatant from the bacterial cultures, and corresponded to chromate reduction. The activity of chromate reduction by
the bacterium was not related to enzymes or reducing sugars, while fluorometric assay suggested that glutathione, a chromate-reducing
substance which was produced by the bacterium, was one of the factors that contributed to the reduction of Cr(VI). 相似文献
19.
A protocol for in vitro induction of crape myrtle tetraploids using nodes from in vitro-grown shoots (2n = 48) was established. Nodal buds were excised from in vitro-grown shoots, maintained on proliferation medium containing
Murashige and Skoog medium supplemented with 4.44 μM 6-benzyladenine , 0.54 μM α-naphthaleneacetic acid, and treated with
a range of concentrations of colchicine under three different conditions. Nodal bud explants treated in liquid proliferation
medium supplemented with either 15 or 20 mM colchicine for 24 h turned necrotic and died; whereas, those cultured on solid
proliferation medium supplemented with either 125 or 250 μM colchicine for 30 days survived, but no tetraploid plants were
obtained. However, when explants were cultured in liquid proliferation medium containing 250, 500 or 750 μM colchicine for
10 days, tetraploid plants (2n = 96) were obtained. Incubation of explants in medium containing 750 μM colchicine promoted the highest frequency of survival
(40%) of explants and of recovered tetraploids (60%). Morphological and anatomical characteristics of leaves, including leaf
index, stomata size and number, stomata index (length/width), and number of chloroplasts in guard cells correlated with ploidy
of crape myrtle plants. The number of chloroplasts in guard cells of stomata was a stable and reliable marker in discriminating
plants of different ploidy levels. Chromosome counts and flow cytometry confirmed these findings. 相似文献