RESUMEN
This work aims to produce bio-surfactant using a brewery waste (trub) as a strategy to reduce production costs related to the substrate, as well as to provide an eco-friendly destination for this residue. Trub is obtained during the boiling of the wort, being mainly composed of proteins and reducing sugars. To evaluate important process parameters on bio-surfactant production, a full factorial design (24) was elaborated, having agitation rate and concentrations of trub, yeast extract, and peptone as independent variables. The highest bio-surfactant concentration achieved was 100.76 mg L-1, where FTIR and Maldi-ToF-MS confirmed functional groups characteristic of peptides and isomers of surfactin in the bio-surfactant extract. Trub, agitation and yeast extract showed statistically significant effects on the response variable (surface tension), where an increase in the agitation rate and in the concentration of yeast extract demonstrated a positive impact on the production of bio-surfactant.
Asunto(s)
Cerveza , Carbono/metabolismo , Residuos Industriales , Tensoactivos/metabolismo , Fermentación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Espectroscopía Infrarroja por Transformada de Fourier , Tensión SuperficialRESUMEN
Surfactin has potential as next generation antibiofilm agent to combat antimicrobial resistance against emerging pathogens. However, the widespread industrial applications of surfactin is hampered by its high production cost. In this work, surfactin was produced from Bacillus subtilis using a low-cost brewery waste as a carbon source. The strain produced 210.11â¯mg⯠L - 1 after 28â¯h. The antimicrobial activity was observed against all tested strains, achieving complete inhibition for Pseudomonas aeruginosa, at 500⯠µ gâ¯mL - 1 . A growth log reduction of 3.91 was achieved for P. aeruginosa while, Staphylococcus aureus and Staphylococcus epidermidis showed between 1 and 2 log reductions. In the anti-biofilm assays against P. aeruginosa, the co-incubation, anti-adhesive and disruption showed inhibition, where the greatest inhibition was observed in the co-incubation assay (79.80%). This study provides evidence that surfactin produced from a low-cost substrate can be a promising biocide due to its antimicrobial and anti-biofilm abilities against pathogens.