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.

The synthesis of bioplastics from renewable resources is essential for green living. PHBV (poly(3-hydroxybutyrate-co-3-hydroxyvalerate)) is a biodegradable and biocompatible material ideal for various industrial applications. The impact of levulinic (LA), valeric acids (VA), and sodium propionate (SPr) as co-substrates in biomass and the synthesis of 3-hydroxy valerate (3HV) and co-polymerization of PHBV by Burkholderia thailandensis E264 (BtE264) was assessed. Thermogravimetric, XRD, NMR, and mechanical characterization were performed on the homopolymer (PHB) and co-polymer (PHBV), and compared to the PHBV-STD. BtE264 produced the co-polymer PHBV when adding any of the three co-substrates. LA showed a higher positive effect on microbial growth (8.4 g∙L⁻¹) and PHBV production (3.91 g∙L⁻¹), representing 78 and 22 mol % of 3HB and 3HV, respectively. The PHBV obtained with LA had a melting temperature (Tm) lower than the PHB homopolymer and presented lower values for melting enthalpies (ΔHf); the degree of crystallization and TGA values indicated that PHBV had better thermal stability. Additionally, FTIR and NMR revealed that BtE264 synthesizes PHBV with an organization in monomeric units (3HB-3HV), suggesting differentiated incorporation of the monomers, improving 3.4 times the break elongation the co-polymer’s tensile properties. This study highlights the co-substrates’ relevance in PHBV synthesis using BtE264 for the first time.

Chlorogenate hydrolase catalyzes the hydrolysis of chlorogenic acid, releasing caffeic and quinic acids. This enzyme can be used to extract caffeic acid from agro-industrial byproducts (apple marc, coffee pulp, brewer's spent grain, among others), and to synthesize caffeic acid derivatives. This work aimed to isolate and identify fungal strains capable of producing enzymes with chlorogenate hydrolase activity. Twelve fungal strains were isolated from fresh coffee cherries, dry coffee cherries, and green coffee beans. The isolated fungi were analyzed for their morphology and ability to assimilate chlorogenic acid. Four fungal isolates were identified as Aspergillus sp., two as Fusarium sp., and one as Cladosporiumsp. All the fungal isolates were able to grow using chlorogenic acid as the sole carbon source. The CR1 strain, identified as Aspergillus niger by sequencing of the ITS region, was selected due to its high radial growth rate (0.27 ± 0.01 mm h-1). This strain grew and showed chlorogenate hydrolase activity in Submerged (SmF) and Solid-State Fermentation (SSF). The maximum chlorogenate hydrolase activity in SSF (34.6 ± 11.8 U/L) was 2.1-fold higher than in SmF (16.2 ± 1.6 U/L). These results provide the basis for developing applications based on the use of enzymes with chlorogenate hydrolase activity.