A Study On Blood Hemolysis Essay
997 WordsApr 14, 20164 Pages
A portion of (2–3 mg) from the partially purified polysaccharide powder was mixed with KBr then pressed into a disk. The whole infrared spectrum was analyzed at a scan range of 4000–400 cm-1. Thirty scans were taken with 4 cm-1 resolution. CO2 and H2O corrections were incorporated. Reproducibility of the normalized spectra was ±2%. (Shanthi et al., 2014).
3.16. Testing isolates probiotic properties
3.16.1. Blood hemolysis
Hemolysis test was performed according to the method described by Guttmann and Ellar (2000). Overnight cultures of isolated Enterococcus durans and Enterococcus hirae were streaked on blood agar and incubated at 37°C for 24 h. Blood agar plates were examined for signs of hemolysis. Blood hemolysis test was performed in duplicates.
3.16.2. Resistance to low pH
Isolates Enterococcus durans and Enterococcus hirae were tested for their ability to resist low pH values as follow, 25 ml of sterile MRS broth adjusted to pH 6.4, 4, 3 and 2 was inoculated using 1% (v/v) of an overnight culture, then incubated at 37ºC for 6 h. The absorbance at 620 nm was monitored using spectrophotometer (Unico, USA) at hourly intervals (Nawaz et al., 2011).
3.16.3. Bile salts tolerance
The selected isolates were examined for their ability to grow in presence of different concentrations of bile salts. The two concentrations 0.1% and 0.3% (w/v) were used for this purpose. An aliquots of 20 ml sterile MRS broth supplemented with 0, 0.1% and 0.3% bile salts were inoculated with