Screening and selection of surfactant‐producing bacteria from waste lubricating oil

• Published in: Journal of Applied Bacteriology 1996-08, Vol.81 (2), p.161-166
• Main Authors: Mercadé, M.E., Monleón, L., Andrés, C., Rodón, I., Martinez, E., Espuny, M.J., Manresa, A.
• Format: Article
• Language: English
• Subjects: Bacillus; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biotechnology; Fundamental and applied biological sciences. Psychology; Isolation and description; Mission oriented research; Rhodococcus
• ISSN: 0021-8847; 2056-5232
• DOI: 10.1111/j.1365-2672.1996.tb04494.x

Forty‐four strains with the ability to grow on waste lubricating oil as sole carbon source were isolated from soil‐contaminated samples and identified. Of these, four Rhodococcus and one Bacillus strain were selected for their capacity to lower the surface tension of culture medium from 55 mN m‐1 to less than or equal to 40 mN m‐1 and the interfacial tension between the culture medium and kerosene from 21 mN m‐1 to less than 5 mN m‐1, respectively. The surface‐active compounds, identified by means of TLC and specific reagents, from cultures of Rhodococcus strains and Bacillus were glycolipids and lipopeptide, respectively. The percentage loss of waste lubricating oil after 120 h of incubation ranged from 7.87% to 45.8% depending on the strain selected compared with uninoculated control. Decreases in paraffinic compounds and accumulation of new products, mainly with amide groups, were observed by direct and differential infrared spectrometry when selected strains grew on waste lubricating oil.