Volume and type of medium, carbohydrate concentration, carbohydrate ratios, and inoculum level were investigated as possible factors influencing total colony counts of anaerobic rumen bacteria obtained in roll tubes (18 by 150 mm). Colony counts were lower when the rumen fluid was clarified by centrifugation before inclusion in the medium; however, decreasing the volume of 40% rumen fluid gluco...

A quantitative assay of infective yellow fever virus particles was developed that is based on the enumeration of cells containing fluorescent viral antigen 24 hours after infection of coverslip McCoy cell cultures. The rapidity and efficiency of virus adsorption onto cell monolayers was markedly enhanced by centrifugation of virus inoculum. By this procedure, 95% of virus was adsorbed within 15...

Five different parameters, time of incubation of the culture, type of culture medium, inoculum, strain of inbred mice, and age of mice, were tested using the LD50 technique to standardize a murine model for the evaluation of the virulence of Streptococcus suis capsular type 2 isolates. A model using 28 day-old mice belonging to CF1 strain appeared to give the best results. The inoculum size was...

A quantitative assay for infective variola virus particles was developed which is based on the enumeration of cells containing fluorescent viral antigen after infection of McCoy cell monolayers. The direct fluorescent-antibody technique was employed to stain cells. The efficiency of virus adsorption was markedly enhanced by centrifugation of virus inoculum onto McCoy cell monolayers at 500 x g ...

Experiments on methanogenesis from horse dung were conducted in laboratory-scale batch reactors in order to determine the substrate performance in a solid-phase digestion process, more specifically in terms of potential energy recovery and suitable process technology. Dung from a horse stable with straw bedding was used. The temperature was kept in the mesophilic range. In the percolation proce...

Pure strains of Purple Non-Sulfur (PNS) bacteria: Rhodobacter sphaeroides strain O.U 001 was studied for its efficiency to produce biohydrogen using the photofermentative pathways. An annular photobioreactor was being designed aiming the uniform light distribution. In prototype annular photobioreactor, at an initial pH of 6.8±0.2, temperature 32 ± 2 ◦C, inoculum volume 10% (v/v), inoculum age o...

An analysis of 47 episodes of bacterial arthritis showed that applying a blood culture procedure to the culture of joint fluids gave positive results in 10 cases (21%) that were negative by conventional methods. When follow up samples taken during antibiotic treatment were considered the proportion of false negatives eliminated rose to 40%. The respective advantages of using a large volume of i...

A simple procedure for preparing glycerol-cryoprotected Lactobacillus casei cultures has been developed. L. casei grown in medium supplemented with low concentrations of folic acid (0.3 micrograms/L) is diluted with an equal volume of glycerol (800 mL/L) and stored at -20 degrees C. Growth response of the glycerol-cryoprotected L. casei to low concentrations of folic acid exceeded that of cult...

Alkaline polygalacturonate lyase (PGL), which was the central enzyme of green environmental treatment technology, has been widely used in textile, papermaking and beverage production. In previous work, Bacillus subtilis as expression host, PGL gene derived from B. WSHB04-02 successfully expressed engineered strain WB43CB by regulating molecular elements such signal peptide, promoter SD sequence...