الفهرس 
acknowledgmentOnly 14 pages are availabe for public view
 |  | from | 199 |  |  |
| | | from | 199 | | |
Abstract
Streptomyces nasri Hashem and Diab was described as a new species isolated from the desert soil of Kuwait. The organism was reported to produce antibiotic substances (s) active against some Gram-positive bacteria (Hashem and Diab, 1973).
The phenomenon of antibiosis is not a new discovery. As early as 1877, Pasteur noted that certain air - born saprophytic organisms were capable of inhibiting the growth of anthrax bacillus. On the agar plate-culture of Staphylo- coccus aureus, Fleming (1929) found a green mold contaminant which produced a green pigment and prevented bacterial growth for a distance around it. He cultivated the mold in broth and found that a filtrate of the culture had the power - even when greatly diluted to prevent growth of a number of pathogenic bacteria. Since the mold proved to be a species of Penicillium, Fleming named the antibiotic peni- cillin.
Dubos (1939) isolated a spore-bearing bacillus from the soil that was capable of destroying living Gram-positive cocci. Autolysed cultures of the organism were capable of destroying living micrococci, pneumococci and certain streptococci. The organism proved to be Bacillus brevis, a large Gram positive, spore producing rod, similar to Bacillus subtilis. He named the antibiotic gramicidin. The addition of gramicidin to nutrient broth prevented the.