Fungistatic and Fungicidal Capacity of a Biosurfactant Extract Obtained from Corn Steep Water

Abstract

Biosurfactants are surface-active compounds that are produced by microorganisms, which in addition to their surfactant capacity, can possess interesting antimicrobial activities that are used in their incorporation into the agrifood industry. In this work, the preservative capacity of a novel biosurfactant extract obtained from a residual stream of the corn-milling industry was evaluated against two different fungi (Aspergillus brasiliensis and Candida albicans) under different biosurfactant concentrations (0.33–0.99 mg/mL), temperatures (4–40 °C), and incubation times (5–11 days). All the assays started with the same concentration of fungi (2 × 106 CFU/mL). The results showed that temperature played an important role in the bactericidal and fungistatic effects of this biosurfactant extract. It was observed that at a low biosurfactant concentration (0.33 mg/mL) and low or high temperatures in the range tested, this biosurfactant extract possessed an important fungicidal effect (complete inhibition) on A. brasiliensis, while at intermediate temperatures, it achieved a fungistatic effect (50% of inhibition). Regarding C. albicans, it was observed that this strain was more resistant than A. brasiliens, although it was possible to achieve growth inhibitions of 76.3% at temperatures of 40 °C after 8 days of incubation with a biosurfactant concentration of 0.99 mg/mL. This work supports the possible application of biosurfactants extracted from corn steep water as preservatives and antimicrobial agents against fungal contaminations on agrifood products.

Adding value to secondary streams of corn wet milling industry

“…The biosurfactant extract obtained from CSL, after different steeping process, possesses a quite homogeneous composition. Regarding the capacity to reduce the surface tension, the biosurfactant extract obtained from CSL, in the current work, was able to reduce the surface tension of water up to 39.3 ± 0.5 mN/m with a CMC of 320.2 ± 12.9 mg/L which was also in consonance with the results obtained in previous works (López-Prieto et al, 2020, 2019b.…”

Lycopene, Mesoporous Silica Nanoparticles and Their Association: A Possible Alternative against Vulvovaginal Candidiasis?

“…The big difference between fungicidal and fungistatic compounds lies in the fact that the first one is able to inhibit 99.9% of fungal growth, while the second has a lower inhibition (50%). Another definition also used is that fungicidal compounds are those that inhibit the regrowth (for many hours) of the pathogen after a limited exposure for a certain period of time, whereas fungistatic compounds would be those where, after its removal, a rapid new growth would be observed [ 64 , 65 ]. Thus, it can be said that this classification may be related to the amount/time of cell death permanence and not to the mechanism of the death cause.…”

Mannosylerythritol lipids as green pesticides and plant biostimulants

“…However, the authors concluded that the results obtained showed satisfactory antimicrobial effects of CSW on pathogenic fungi. 51 Copper oxychloride (Cu-Oxy) is a fungicide commonly used to control plant diseases. Fungicide formulations often feature chemical surfactants to optimize product efficiency.…”

“…On the other hand, C. albicans showed resistance to inhibiting growth. However, the authors concluded that the results obtained showed satisfactory antimicrobial effects of CSW on pathogenic fungi 51 …”