A gram-positive, nonfermentative, rod-shaped bacterium designated ST-5, identified as Rhodococcus, was isolated from Kuwait soil. Grown on hydrocarbon, such as kerosene and n-paraffin, the bacterium produced surface-active compounds (biosurfactants). Neasurements of surface tension, critical micelle dilution and emulsifying activity indicated that the biosurfactant is produced as a primary metabolite. The ST-5 culture surface-active component is mainly giycolipid in nature. Whole-culture broth dropped surface tension to values below 27 mN/m and was stable during exposure to high salinity (10% NaCI), elevated temperatures (120°C for 15 min) and a wide range of pH values. The culture broth was effective in recovering up to 86% of the residual oil from oil-saturated sand packs, indicating potential value in enhanced oil-recovery processes.

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Three brands of commercial honey were tested for their inhibitory effect on the growth of Helicobαcter pylori. H. pylori were isolated from gastric mucosa biopsy specimens using both pour plate and well inhibition zone techniques. At a concentration of 20% and above, all samples of honey were found to inhibit growth. This is the first report of the inhibitory effect of commercial honey on H. pylori. It may be of potential benefit in the treatment of peptic ulcer disease.