Characterization of biosurfactant produced through co-utilization of substrates by the novel strain Pseudomonas aeruginosa NG4

Biosurfactants are extremely valuable and promising compounds that have a wide range of applications across various industries and aspects of human life. Thus, there is a great need to enhance their production yield, by developing new and more efficient fermentation methods. In pursuit of this objective, batch fermentation was carried out with different feed concentrations and addition. The results were compared in relation to their effectiveness in producing biosurfactants using Pseudomonas aeruginosa. Batch fermentation experiments were conducted using two different substrates feeding strategies, such as single substrate utilization and co-utilization of substrates. The comparison of these substrates utilization processes revealed that the co-utilization of glucose and crude glycerol was a superior cultivation strategy compared to the single substrate utilization for biosurfactant production. The biosurfactant production by P. aeruginosa from co-utilization of glucose and crude glycerol reached to a yield of 2.5 gL^-1. There was about 2.2 fold enhancement in the yield compared to single carbon substrates. Such co-utilization of substrates is not reported for biosurfactant production. The biosurfactant was characterized and the presence of mono-rhamnolipid and di-rhamnolipid compounds was confirmed through FT-IR and LC-MS.