Bacillus sp. GY19 was immobilized on chitosan to increase cell density and facilitate lipopeptide production.
Palm oil was added to a waste glycerol based medium as precursor for the lipopeptides. The
immobilized cells could be reused in stirred tank fermenter for at least 6 cycles with an optimal condition
of 80 g/L immobilized cells, 10% (v/v) waste glycerol and 1.25% (v/v) palm oil. The highest lipopeptide
concentration observed during the steady state was 7.12 g/L. The presence of chitosan in the fermenter
reduced foaming problems due to its absorption property, which could interrupt the aggregation of air
bubble and lipopeptides. The lipopeptides were separated and purified from the culture medium by a
simple design foam fractionation unit. The amounts of lipopeptides in foamate produced from palm oil
and crude palm oil added culture media were 10.9 and 9.8 g/L, respectively. HPLC profile of lipopeptide
extracted from the foamate had less impurity peaks than that from the culture medium. Both foamate
samples showed 100% oil displacement efficiency with diesel oil, followed by Arabian light oil and heavy
oil. It is thus possible to apply the sequential lipopeptide production and recovery process for producing
a ready-to-use foamate for petroleum remediation.