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- Isolation and Analyses of Uranium Tolerant Serratia marcescens Strains and Their Utilization for Aerobic Uranium U(VI) Bioadsorption
- Rakshak Kumar , Celin Acharya , Santa Ram Joshi
- J. Microbiol. 2011;49(4):568-574. Published online September 2, 2011
- DOI: https://doi.org/10.1007/s12275-011-0366-0
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- 52 Scopus
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Abstract
- Enrichment-based methods targeted at uranium-tolerant populations among the culturable, aerobic, chemoheterotrophic bacteria from the subsurface soils of Domiasiat (India’s largest sandstone-type uranium deposits, containing an average ore grade of 0.1% U3O8), indicated a wide occurrence of Serratia marcescens. Five representative S. marcescens isolates were characterized by a polyphasic taxonomic approach. The phylogenetic analyses of 16S rRNA gene sequences showed their relatedness to S. marcescens ATCC 13880 (≥99.4% similarity). Biochemical characteristics and random amplified polymorphic DNA profiles revealed significant differences among the representative isolates and the type strain as well. The minimum inhibitory concentration for uranium U(VI) exhibited by these natural isolates was found to range from 3.5-4.0 mM. On evaluation for their uranyl adsorption properties, it was found that all these isolates were able to remove nearly 90-92% (21-22 mg/L) and 60-70% (285-335 mg/L) of U(VI) on being challenged with 100 μM (23.8 mg/L) and 2 mM (476 mg/L) uranyl nitrate solutions, respectively, at pH 3.5 within 10 min of exposure. his capacity was retained by the isolates even after 24 h of incubation. Viability tests confirmed the tolerance of these isolates to toxic concentrations of soluble uranium U(VI) at pH 3.5. This is among the first studies to report uranium-tolerant aerobic chemoheterotrophs obtained from the pristine uranium ore-bearing site of Domiasiat.
- Comparative Evaluation of Three Purification Methods for the Nucleocapsid Protein of Newcastle Disease Virus from Escherichia coli Homogenates
- Yan Peng Tan , Tau Chuan Ling , Khatijah Yusoff , Wen Siang Tan , Beng Ti Tey
- J. Microbiol. 2005;43(3):295-300.
- DOI: https://doi.org/2210 [pii]
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Abstract
- In the present study, the performances of conventional purification methods, packed bed adsorption (PBA), and expanded bed adsorption (EBA) for the purification of the nucleocapsid protein (NP) of Newcastle disease virus (NDV) from Escherichia coli homogenates were evaluated. The conventional methods for the recovery of NP proteins involved multiple steps, such as centrifugation, precipitation, dialysis, and sucrose gradient ultracentrifugation. For the PBA, clarified feedstock was used for column loading, while in EBA, unclarified feedstock was used. Streamline chelating immobilized with Ni^2^+ ion was used as an affinity ligand for both PBA and EBA. The final protein yield obtained in conventional and PBA methods was 1.26% and 5.56%, respectively. It was demonstrated that EBA achieved the highest final protein yield of 9.6% with a purification factor of 7. Additionally, the total processing time of the EBA process has been shortened by 8 times compared to that of the conventional method.
- Purification of Filamentous Bacteriophage M13 by Expanded Bed Anion Exchange Chromatography
- Tau Chuan Ling , Chee Kin Loong , Wen Siang Tan , Beng Ti Tey , Wan Mohammad Wan Abdullah , Arbakariya Ariff
- J. Microbiol. 2004;42(3):228-232.
- DOI: https://doi.org/2084 [pii]
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Abstract
- In this paper, we investigated the development of a simplified and rapid primary capture step for the recovery of M13 bacteriophage from particulate-containing feedstock. M13 bacteriophage, carrying an insert, was propagated and subsequently purified by the application of both conventional multiple steps and expanded bed anion exchange chromatography. In the conventional method, precipitation was conducted with PEG/NaCl, and centrifugation was also performed. In the single step expanded bed anion exchange adsorption, UpFront FastLine^TM 20 (20 mm i.d.) from UpFront Chromatography was used as the contactor, while 54 ml (H_o=15cm) of STREAMLINE DEAE (r=1.2 g/cm^3) from Amersham Pharmacia Biotechnology was used as the anion exchanger. The performance of the two methods were evaluated, analysed, and compared. It was demonstrated that the purification of the M13 bacteriophage, using expanded bed anion exchange adsorption, yielded the higher recovery percentage, at 82.86%. The conventional multiple step method yielded the lower recovery percentage, 36.07%. The generic application of this integrated technique has also been assessed.
- Adsorption of Pb^2+ in the components of bacterial cell membrane
- Kim , Mal Nam
- J. Microbiol. 1995;33(4):278-282.
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Abstract
- S. epidermidis cell was fractionated into cell wall, cell membrane and cytoplasm. The cell membrane adsorbed the most abundant Pb^2+ per unit dry weight of the three fractions tested. Adsorption behavior of Pb^2+ in lipid and protein, which are the main components of the cell membrane, indicated that phosphatidylethanolamine and phosphatidylinositol having phosphoryl group and gangliosides containing carboxyl groups adsorbed much more Pb^2+ than triglycerides lacking any chargeable functional groups. Protein purified from cell membrane adsorbed larger amount of Pb^2+ than total native cell membrane or cell membrane lipid.
- Heavy Metal Biosorption and its Significance to Metal Tolerance of Streptomycetes
- Jae-young Rho , Jae-heon Kim
- J. Microbiol. 2002;40(1):51-54.
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Abstract
- Heavy metal adsorptions of four streptomycetes were compared with each other. Among the test strains, Streptomyces viridochromogenes showed the most efficient metal binding activity, which was carried out by cell wall as well as freeze-dried mycelium. An order of adsorption potential (zinc > copper > lead > cadmium) was observed in single metal reactions, whereas this adsorption order was disturbed in mixed-metal reactions. The metal adsorption reactions were very fast, pH dependent and culture age-independent, suggestive of a physico-chemical reaction between cell wall components and heavy metal ions. The metal tolerant stains presented the weakest adsorbing activity, indicating that the metal biosorption was not the basis of the metal tolerance.
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