In this study, the effects of some factors on bacterial growth and ferrous oxidation rates were investigated by Acidithiobacillus ferrooxidan in 250 ml shake flasks. One factor at a time (OFAT) design approach was used for preliminary evaluation of various factors affecting the process, such as pH, initial ferrous and elemental sulfur concentrations, shaker agitation rate, and liquid to flask v...

Sucrose is the most cariogenic dietary carbohydrate because it is a substrate for insoluble extracellular polysaccharide (IEPS) production in dental biofilms, which can proportionally decrease bacterial density and, consequently, the number of biofilm calcium (Ca) binding sites. Ca bound to bacterial cell walls can be released into the biofilm fluid during a cariogenic challenge, reducing the d...

Suspensions of aerobic bacteria often develop flows from the interplay of chemotaxis and buoyancy. We find in sessile drops that flows related to those in the Boycott effect of sedimentation carry bioconvective plumes down the slanted meniscus and concentrate cells at the drop edge, while in pendant drops such self-concentration occurs at the bottom. On scales much larger than a cell, concentra...

Objective High concentration of iron and other trace elements could restrict bacterial growth and modify their metabolic pattern as well. However, this study aimed to find out the influence of iron, chromium, cadmium and synergism or antagonism between these elements on the growth of a gram positive bacterium. Materials and Methods In a series of experiments, Bucillus cereus was cultured in a n...

objective high concentration of iron and other trace elements could restrict bacterial growth and modify their metabolic pattern as well. however, this study aimed to find out the influence of iron, chromium, cadmium and synergism or antagonism between these elements on the growth of a gram positive bacterium. materials and methods in a series of experiments, bucillus cereus was cultured in a n...

Cultures of Streptococcus bovis and mixed populations of rumen bacteria were used to investigate the concentration of ATP and rumen bacterial numbers at various stages of growth. ATP, extracted with Tris buffer, was analyzed using the firefly luciferin-luciferase bioluminescent reaction. ATP concentrations of S. bovis and mixed cultures of rumen bacteria significantly correlated with live cell ...

background: acute bacterial meningitis is among serious infections of the central nervous system (cns). the early diagnosis and empiric antibiotic treatments have led to a reduction in morbidity and mortality rates. pcr and the enzymatic digestion of 16s rdna fragment following the pcr by universal primers led up fast and sensitive determination. the aims of the present study was to improve our...

Measurements were made of the yield coefficient during the aerobic metabolism of glucose by a heterogeneous bacterial mixture. Expressed in terms of carbon, the coefficient was approximately 0.48. The value did not vary with initial bacterial densities ranging from 0.4 pg to 40 micrograms of cell carbon per ml and with glucose concentrations ranging from 43 pg to 100 micrograms of carbon per ml...

Lactic acid concentration was determined in 37 specimens of cerebrospinal fluid by gas liquid chromatography. It was found to be raised ( ~ 30 mg/dl) in 15 specimens from culture positive cases of bacterial meningitis and one of fungal meningitis. It was < 30 mg/dl in cerebrospinal fluid from four cases of viral meningoencephalitis and 10 contaminated specimens. It was also raised in two specim...