The
lipA gene, encoding a solvent-tolerant
extracellular lipase from
Proteus
sp. SW1, was displayed
on the cell surface of
Escherichia coli
by fusing it to an
antigen 43 anchoring motif. The display of LipA on the
Escherichia coli cell surface was directly confirmed by
immunofluorescence microscopy and flow cytometry. After
6 days of incubation in media containing 1 % used cooking
oil, an
Escherichia coli strain expressing surface displayed
lipase was able to degrade 27 % of the oil. The biosurfactant, pseudopyronine B, was purified from culture
supernatants of
Pseudomonas
sp. SL31. Its critical micelle
concentration was determined to be 1400 mg/l, and the
surfactant was stable within a temperature range from 0 to
120 C and a pH range of 3–11. Pseudopyronine B-containing crude media extracts efficiently removed up to
51 % of the cadmium from contaminated water. We
demonstrated the oil degradation ability of the mixed culture of four bacterial strains, namely the recombinant
Escherichia coli expressing cell surface displayed lipase
(pKKJlipA), His-tagged lipase (pETlipA), extracellular
lipase-producing
Proteus sp. SW1, and pseudopyronine
B-producing
Pseudomonas sp. SL31 by culturing in LB
media containing 1 % oil. The consortium degraded 29 %
of oil in one day and reached 84 % after 7 days.
