A study of the growth curves of C. xerosis and E. coli Bacteria in Mediums Containing Cobalt Ferrite Nanoparticles

2004 ◽  
Vol 820 ◽  
Author(s):  
Marjorie Flores ◽  
Nanell Colón ◽  
Omayra Rivera ◽  
Nicole Villalba ◽  
Yahira Baez ◽  
...  
Keyword(s):  
Cobalt Ferrite ◽  
Growth Curves ◽  
Precipitation Method ◽  
Adaptation Period ◽  
E Coli ◽  
Standard Curve ◽  
Stable Suspension ◽  
Electric Polarity ◽  
The One ◽  
Co Precipitation

AbstractPrevious publications demonstrated the sensibility of the bacteria, when these were reproduced in mediums that contain nanoparticles of luminescent silicon. The mentioned effect takes place in the development of a bacteriological sensor. The present investigation is centered on the study of the growth curves of E. coli and C. xerosis, but now in the presence of nanosize particles of Cobalt Ferrite (CoFe2O4) which were produced by the co-precipitation method in a watery phase. These nanoparticles present ferromagnetism characteristics (coercivity at room temperature among 600-5000 Oe for a size around 15-40nm). The experiment results evidence that the adaptation period of the bacteria, in contact with a stable suspension of nanoparticles of Ferrite, shows a growth curve of above the one obtained in absence of the nanoparticles (standard curve). The probable interaction of the electric polarity that these possess should be involved with the observed phenomena.

Effect of Zinc Oxide Nanocrystals in Media Containing E. coli and C. xerosis Bacteria

2005 ◽  
Vol 900 ◽  
Author(s):  
Triana Merced ◽  
Stephanie Santos ◽  
Omayra Rivera ◽  
Nicole Villalba ◽  
Yahira Baez ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Room Temperature ◽  
Cobalt Ferrite ◽  
Growth Curves ◽  
Adaptation Period ◽  
E Coli ◽  
Standard Curve ◽  
Stable Suspension ◽  
Zno Nanocrystals ◽  
Doped Zno

ABSTRACTThe present investigation is centered on the study of the growth curves of E. coli and C. xerosis bacteria in the presence of nanosize particles of Zinc Oxide. Previous works demonstrated the sensitivity of the bacteria, when these were reproduced in media that contain nanoparticles of luminescent silicon and Cobalt Ferrite. Doped ZnO nanocrystals were synthesized by conventional precipitation in ethanol solutions as reported by Spanhel and Anderson for bare ZnO. In our case, the syntheses were carried out under room-temperature conditions.The experimental results of E. coli bacteria in contact with a stable suspension of nanoparticles of Zinc Oxide, shows a growth curve without adaptation period. Moreover a short and slowly logarithmic stage has been observed, reaching the stationary stage after approximately four hours compared with one in absence of the nanoparticles (standard curve). During the observations, a change in the lifetime of the bacteria (metabolism) with particulate was noticed,as well as the beginning of the mortality stage. However, different results were recorded for silicon and ferrite. For the case of the bacteria C. xerosis, the curve with particles is above its standard curve, for all times with none of the oscillations which occured in the nanometer silicon. For these bacteria the beginning of the mortality stage is observed when they have particles. For both bacteria with Zinc Oxide nanoparticles this occurs approximately after nine hours.

Composition and magnetic properties of cobalt ferrite nano-particles prepared by the co-precipitation method

2010 ◽  
Vol 322 (21) ◽  
pp. 3470-3475 ◽  
Author(s):  
Yue Zhang ◽  
Zhi Yang ◽  
Di Yin ◽  
Yong Liu ◽  
ChunLong Fei ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Cobalt Ferrite ◽  
Nano Particles ◽  
Precipitation Method ◽  
Co Precipitation

Comparative Study Of The Growth Curves Of B. subtilis, K. pneumoniae, C. xerosis And E. coli Bacteria In Medium Containing Nanometric Silicon Particles

2002 ◽  
Vol 737 ◽  
Author(s):  
Lilyanna Pérez ◽  
Marjorie Flores ◽  
J. Avalos ◽  
L. San Miguel ◽  
O. Resto ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Growth Curve ◽  
Silicon Nanoparticles ◽  
Silicon Film ◽  
Growth Curves ◽  
Bacterial Strains ◽  
E Coli ◽  
Standard Curve ◽  
Nanometric Particles ◽  
Silicon Particles

ABSTRACTIn this research nanometric particles from luminescent (625nm) porous silicon film were synthesized. This particles were later inoculated in bacterial strains of B. subtilis (BSi) and K. pneumoniae (KSi). A comparison of the behavior of their growth curve and the ones reported for C. xerosis (XSi) and E. coli (ESi) in presence of silicon nanoparticles is presented. The growth curve of BSi, as well as the KSi, present changes compared to their standard curves. The BSi growth curve grows below the standard curve after the fifth hour, while in the KSi this happens after the eighth hour. Based on our preliminary findings we can speculate that at this point in time a critical population is present, and this may give rise to the possible incorporation of the silicon particles by the bacteria, or a possible pleomorphism inhibits reproduction. The stationary region, in both cases, takes place sooner than in the standard curve. No significant oscillations are observed in any case, which differs form the XSi curve, were oscillations of intervals of almost 1 hour were reported. In addition, these curves have a different behavior when compared to the ESi growth curve, in which no significant differences between the standard and the particle containing sample were reported.

Sonochemical Co-Precipitation Synthesis of Gallic Acid-Modified Magnetite

2015 ◽  
Vol 1101 ◽  
pp. 286-289 ◽  
Author(s):  
Maya Rahmayanti ◽  
Sri Juari Santosa ◽  
Sutarno
Keyword(s):  
Magnetic Properties ◽  
Gallic Acid ◽  
Precipitation Method ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
One Step ◽  
The Fourier Transform ◽  
The One ◽  
Co Precipitation

Gallic acid-modified magnetites were synthesized by one and two-step reactions via the newly developed sonochemical co-precipitation method. The two-step reaction included the formation of magnetite powder and mixing the magnetite powder with gallic acid solution, while the one-step reaction did not go through the formation magnetite powder. The obtained gallic acid-modified magnetites were characterized by the Fourier Transform Infrared (FTIR) spectroscopy, the X-Ray Diffraction (XRD) and the Scanning Electron Microscopy (SEM). More over, the magnetic properties were studied by using a Vibrating Sample Magnetometer (VSM). The characterization results showed that there were differences in crystalinity, surface morphology and magnetic properties of products that were formed by one and two-step reactions.

Study on the Characterization of Zinc Ferrite High-Temperature Coal Gas Desulfurization Agent

2010 ◽  
Vol 129-131 ◽  
pp. 1233-1237
Author(s):  
Hong Yan Xu ◽  
Mei Sheng Liang ◽  
Chun Hu Li
Keyword(s):  
Zinc Ferrite ◽  
Raw Materials ◽  
Particle Diameter ◽  
Textural Properties ◽  
Zinc Nitrate ◽  
Gas Absorption ◽  
Precipitation Method ◽  
Ferric Nitrate ◽  
The One ◽  
Co Precipitation

Using ferric nitrate, zinc nitrate, ammonia liquor and binder as main raw materials, five kinds of zinc ferrite sorbents were prepared by the co-precipitation method. The effects of the different binders on the structure and texture of zinc ferrite sorbents were investigated. The morphology, composite structure, pore properties, and mechanical strength were studied by using modern several physicochemical techniques such as powder X-ray diffraction (XRD), scanning electronic microscopy (SEM), strength tester and gas absorption meter. It is showed that spinel structure ZnFe2O4 is not affected by different binders，and its particle diameter is in micron leve1. The spinel structures are present in the sorbents that have been calcined at 750 0C.. The sorbent employed kaolinite as binder is the best one of the five types of sorbents for desulfurization, while the one employed diatomite is the worst.Different binders modify the textural properties, modifying consequently the sorbent reactivity. Furthermore, the reactivity and sulfur capacity of sorbents are increasing with an increase in the pore volume.

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