Inhibition zone diameter

Table 18.9 Inhibition zone diameter of the unfilled NR, NR/micron-Ti02(R) and NR/n-Ti02(R) composites against E. coli and S. aureus bacteria after 24 h under UV exposure. Reproduced from ref. 94 with permission from Elsevier.)...

Samples Ti02 (R) content (phr) Inhibition zone diameter (mm) E. coli (G ) S. aureus () ... 

Percentage of relative inhibition zone diameter = (Inhibition zone diameter of sample - Inhibition zone of negative control)/Inhibition zone of antibiotic standard X 100... 

As mentioned earlier, a-D-carba-galactopyranose (1) has been found in a fermentation broth of Streptomyces sp. MA-4145, as an antibiotic. The potency of the antibiotic was rather low. A concentration of—125 fig/mh is required in order to produce a standard inhibition zone of 25-mm diameter against Klebsiella pneumoniae MB-1264, using 13-mm assay discs in a disc-plate assay. A sample of the synthetic a-DL-carba-galactopyranose (17) was... 

Fungicidal activity was determined by the disc method and zones of inhibition were recorded by measuring the diameter (mm) of the inhibition zone. Yeast cultures (S. cerevisiae) showed growth inhibition (clear area surrounding disc) by sediment extracts from all stations when compared to control discs. HPLC analysis of sediment extracts showed more than 20 components in the migration profile of each station. Of these components, a fraction demonstrated to possess cytolytic activity in the crude extract (Ve = 24 ml) was present in all stations when compared to the migration profile of the active fraction (Figure 2). 

Diameter of inhibition zone (8 mm paper disk was used), +=less than 11 mm, ++=between 11 and 18 mm, +++=more than 18 mm. Diameter of inhibition zone for kanamicin (10 ng/disk) is 22 mm. 

Difference in diameter of inhibition zone between Bacillus sublilis M45 (rec -) and HI 7 (rec +), diameter of inhibition zone on M45 minus that on H17 —diameters are same, =less than 2 mm, +=between 2 and 5 mm, ++=more than 5 mm. A positive control is mitomycin C (0.75 (ig/disk) the difference of inhibition zone is 6 mm. Inhibition zones of a negative control (kanamicin) were same for the both strains cCCfo of doxorubicin was 2 ng/mL. 

Note 1 Kirby-Bauer Test - acceptable zone diameter (of inhibition) is greater than the control disk of 6 mm... 

Strain Diameter of the inhibition zone in mm Percentage increase ... 

Mean surface area of the inhibition zones (mm2) was calculated as Ttr2 on the basis of their mean diameter (2r) and % increase was calculated as B-A/A x 100, which was highly significant (p < 0.01). 

The area of inhibition zone displayed by Cf when the drug discs were kept independently on three strains of Vibrio cholerae was between 23.1 and 28.5 mm and that by Fp varied from 18.1 to 21.8 mm. In the tests for joint effect, their diameters became wider and varied from 25.8 to 31.5 mm against Cf and 23.0 to 23.8 mm against Fp. The percent increase in surface area observed with Cf varied from 22.16 to 33.78% and with Fp was from 15.22 to 72.90% (Table 40). 

Diameter of inhibition zone with 12-14 (500 ng/mL) determined by the disk diffusion method. 

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