Biosurfactant synthesis byPseudomonas aeruginosaLBI isolated from a hydrocarbon-contaminated site

Abstract

Aims: Pseudomonas aeruginosa LBI (Industrial Biotechnology Laboratory) was isolated from hydrocarbon‐contaminated soil as a potential producer of biosurfactant and evaluated for hydrocarbon biodegradation. The emulsifying power and stability of the product was assessed in the laboratory, simulating water contamination with benzene, toluene, kerosene, diesel oil and crude oil at various concentrations. Methods and Results: Bacteria were grown at 30°C and shaken at 200 rpm for 168 h, with three repetitions. Surface tension, pH and biosurfactant stability were observed in the cell‐free broth after 168 h of incubation. The strain was able to produce biosurfactant and grow in all the carbon sources under study, except benzene and toluene. When cultivated in 30% (w/v) diesel oil, the strain produced the highest quantities (9·9 g l−1) of biosurfactant. The biosurfactant was capable of emulsifying all the hydrocarbons tested. Conclusion: The results from the present study demonstrate that Ps. aeruginosa LBI can grow in diesel oil, kerosene, crude oil and oil sludge and the biosurfactant produced has potential applications in the bioremediation of hydrocarbon‐contaminated sites. Significance and Impact of the Study: Pseudomonas aeruginosa LBI or the biosurfactant it produces can be used in the bioremediation of environmental pollution induced by industrial discharge or accidental hydrocarbon spills.

Phylogenetic analysis and characterization of an alkane-degrading yeast strain isolated from oil-polluted soil

“…Samples were collected at time 0 and after 3, 6, 10, and 14 days. The biodegrading ability of the strain RG1 was evaluated by monitoring the pH and the cell counts on the Thoma counting chamber (de Cássia Miranda et al, 2007;Pirôllo et al, 2008).…”

Estudos de biodegradação de óleo diesel por consórcio microbiano coletado em Porto Velho - RO, amazônia

“…O índi-ce de emulsificação foi determinado através da adição do diesel (2 mL) ao caldo de cultivo livre de células (2 mL), em tubos de ensaio seguidos por agitação em alta velocidade em vórtex durante 2 min. 17 Os tubos foram deixados em repouso por 24 h e o índice de emulsificação foi calculado através da fórmula: IE= (altura da camada de emulsão/altura total) x 100.…”

Investigation about the efficiency of the bioaugmentation technique when applied to diesel oil contaminated soils

“…By incorporating an electron acceptor such as DCPIP to the culture medium, it is possible to ascertain the ability of the microorganism to utilize the hydrocarbon substrate by observing the color change of DCPIP from blue (oxidized) to colorless (reduced) (Hanson et al, 1993). This technique has been employed in several works, for instance, Roy et al (2002), Cormack and Fraile (1997), Mariano et al (2008a) and Pirôllo et al (2008).…”