In vitro and intracellular antimycobacterial activity of a Bacillus pumilus strain

Despite the declaration of tuberculosis (TB) as a global emergency by the world health organization (WHO) about 20 years ago, the worldwide problem of this disease has worsened due to increased drug resistance of tuberculosis bacilli and acquired immune deficiency syndrome (AIDS) pandemic. Consequently, fight against multidrug and extensively drug-resistant TB is a high priority for public health and research. The present work describes the isolation of a Bacillus pumilus strain secreting a metabolite of protein nature capable of inhibiting mycobacterial growth (Mycobacterium smegmatis, Mycobacterium aurum and Mycobacterium bovis BCG). This metabolite is not toxic, accumulates within the macrophage and inactivates the bacilli with a comparable efficiency to that of the pure commercial antimycobacterial substance Amikacin

Isolation and identification of a Staphylococcus warneri strain with anti-mycobacterial activity

Tuberculosis is the principal cause of death from infection in the world. The resurgence of tuberculosis and the increase in mycobacterial infections, as well as multidrug-resistance of mycobacteria to available antibiotics, has incentivized research on new antimycobacterial agents. Therefore, research based on water and soil samples from the Moroccan biotopes, has led to the isolation of a bacterial strain capable of inhibiting mycobacterial growth (Mycobacterium smegmatis and Mycobacterium aurum A+). The effect was due to an active substance secreted into the culture medium. Sequencing of the 16S rRNA gene identified the strain as belonging to the species Staphylococcus warneri. The active substance precipitated using ammonium sulfate, maintained its inhibitory properties, which were lost when treated with proteinase K. These results indicated that the active substance was protein. Study of the activity of the metabolite revealed its effect on M. smegmatis cell wall, facilitating genomic DNA extraction.Keywords: Tuberculosis, mycobacteria, anti-mycobacterial agents, Staphylococcus warneri, DNA extraction.African Journal of Biotechnology Vol. 12(42), pp. 611

Isolation and identification of Bacillus strains with antimycobacterial activity

Tuberculosis is the principal cause of death worldwide due to an infectious disease. The resurgence of tuberculosis, followed by the increase in prevalence of infections caused by nontuberculous mycobacteria (NTM), as well as the multi-drug resistance of mycobacteria to the majority of currently available antibiotics, have encouraged research for new antimycobacterial agents. Soil and water samples from different Moroccan biotopes, have led to the isolation of four bacterial strains (M, R, G and S), showing an inhibitory effect on mycobacterial growth. This effect was shown to be due to secreted substances in the growth medium. From subsequent analysis it was concluded that these strains produced different active substances. Sequencing of the 16S rRNA showed that these isolates belong to the genus Bacillus. The active substance from isolate M, showed the more important inhibitory effect on mycobacterial growth. It is precipitated with ammonium sulfate and lost all activity when treated with Proteinase K, revealing its protein nature

Air gap membrane distillation: A detailed study of high saline solution

An experimental study is used to examine the effect of high concentration of several salts, i.e., NaCl, MgCl2, Na2CO3 and Na2SO4 on permeate flux and rejection factor by air gap membrane distillation (AGMD). A comparative study involving three different membrane pore sizes (0.2, 0.45 and 1.0 μm) were performed to investigate the influence of pore size on energy consumption, permeate flux and rejection factor. The permeate flux decline is higher than that predicted from the vapour pressure reduction. Furthermore, the energy consumption was monitored at different membrane pore size and was found to be increased when the concentration increased

Solubility of Malladrite Na2SiF6 and K2SiF6 in aqueous solutions

The water activities of binary solutions Na2SiF6-H2O and K2SiF6-H2O are measured from dilution to saturation using the hygrometric method at temperature 353 K. From these experimental data, the activity coefficients of solute were calculated using parameters of ionic interaction model. These coefficients are used to predict the solubility products of the K°sp, the free energy ΔG°diss of dissolution and also the characterization of the precipitated phases to saturation of the system containing Na2SiF6 or K2SiF6. The analyzed of solid phase obtained from saturated solution is made by Xray- diffraction

Contribution a l'etude des proprietes physico-chimiques des magnetites finiment divisees substituees au manganese de formule MnxFe3-xO1 (0x1), et de leurs produits d'oxydation : etude cinetique de la formation de phases spinelles deficitaires en cations

SIGLECNRS T 58946 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Solubility of potassium fluoride in aqueous solution at different temperatures 298.15K–353.15K

In this investigation, the binary aqueous solutions of Potassium Fluoride have been studied using the hygrometric method at different temperatures 298.15K–353.15K. The water activities are measured at molalities from 0.10 mol kg−1 to saturation. The obtained data allow the deduction of osmotic coefficients. From these measurements, the ionic parameters are determined and used to predict the solute activity coefficients. Thermodynamic characteristics, solubility products K°sp and the standard molar Gibbs energy of dissolution ΔG°diss are given. The predicted solubility isotherms are compared with the literature data

Solubility of potassium fluoride in aqueous solution at different temperatures 298.15K–353.15K

In this investigation, the binary aqueous solutions of Potassium Fluoride have been studied using the hygrometric method at different temperatures 298.15K–353.15K. The water activities are measured at molalities from 0.10 mol kg−1 to saturation. The obtained data allow the deduction of osmotic coefficients. From these measurements, the ionic parameters are determined and used to predict the solute activity coefficients. Thermodynamic characteristics, solubility products K°sp and the standard molar Gibbs energy of dissolution ΔG°diss are given. The predicted solubility isotherms are compared with the literature data