Recent Advances in Biosurfactant Production in Solid-State Fermentation

Biosurfactants are amphiphilic molecules synthesized by some microorganisms. Biosurfactants have a wide range of applications in fields such as the bioremediation, petroleum, and pharmaceutical industries. Currently, biosurfactant production is carried out mainly by submerged fermentation (SmF). Biosurfactant production by SmF requires the use of antifoams, which hinder biosurfactant recovery and have a high energy requirement. Biosurfactant production by solid-state fermentation (SSF) has been little explored, but it has some advantages over SmF: it allows the utilization of cheap agro-industrial by-products that function as a support-substrate, does not present foam formation, and allows for improved oxygen and mass exchange. Several research groups have explored different strategies to improve the yields in biosurfactant production by SSF and have demonstrated that it is a viable technology for obtaining these products. Some of the parameters studied are temperature, moisture, substrates, supports, aeration, and, in some cases, agitation. These studies have shown advantages of SSF over SmF for biosurfactant production, such as higher product-substrate yields and higher product concentrations. However, further study of the causes of these results is necessary to implement SSF technology for commercial biosurfactant production.