A Multifunctional Biosurfactant Extract Obtained from Corn Steep Water as Bactericide for Agrifood Industry

Abstract

The increase of crop production along with stricter requirements on food security have augmented the demand of new and eco-friendly bactericides. Most of the bactericides used at the moment consist of persistent organic substances, representing a risk for environmental and human health. For instance, agriculture bactericides used for crop protection includes copper-based, dithiocarbamate and amide bactericides, which are not biodegradable, resulting in the necessity of further research about the production of new active principles that attack microorganisms without producing any harmful effect on human health or environment. The biosurfactant extract evaluated in this work as a bactericide, is obtained from corn steep water, a residual stream of corn wet milling industry, which is fermented spontaneously by probiotic lactic acid bacteria that possess the capacity to produce biosurfactants. In previous works, it has been demonstrated that this biosurfactant extract is able to promote the growth of Lactobacillus casei in drinkable yogurts, though its antimicrobial activity against pathogenic strains has not been evaluated at the moment. The results obtained in this work have proved that this biosurfactant extract is effective as bactericide against Pseudomonas aeruginosa and Escherichia coli, at concentrations of 1 mg/mL, opening the door to its use in agrifood formulations for reducing the use of chemical pesticides and preservatives.

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

“…Regarding its physico-chemical characteristics, the biosurfactant extract from the CSW revealed its ability to reduce the surface tension of water to a minimum value of 43.8 mN/m, which is in concordance with the results shown in previous studies [12,15,21]. Additionally, the CMC obtained for the biosurfactant extract was 306.5 mg/L.…”

“…Additionally, the CMC obtained for the biosurfactant extract was 306.5 mg/L. Regarding the elemental analysis, the N, C, H, and S content showed that C was the element present in the highest proportion with 43.67%, while the contents of N, H, and S were 0.77%, 5.89%, and less than 0.30%, respectively, all of which are in the range of values of previous analysis performed on biosurfactants from CSW [21].…”

“…The experiments were conducted under static conditions to simulate real situations and to test the reproducibility of the study in a real setting. The biosurfactant concentrations used in the factorial design were chosen based on previous experiments of the evaluation of the bactericidal effect of a biosurfactant extract from CSW [21]. The range of temperatures was selected to be between refrigeration storage (4 • C) and a maximum temperature outside on a hot day (40 • C).…”

“…For example, biosurfactants produced by Lactobacillus spp.-such as L. paracasei [18], L. helveticus [19], or L. pentosus [20]-showed antimicrobial properties against foodborne pathogens-such as bacteria like Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, and fungi like A. brasiliensis (also known as A. niger) and C. albicans. Additionally, López-Prieto et al [21] showed that a biosurfactant extracted from a corn stream was effectively able to work as a bactericidal agent against pathogens, such as P. aeruginosa and E. coli, inhibiting their microbial growth at concentrations around 1 mg/mL. Moreover, the ability of biosurfactants in the removal of pathogenic biofilms from E. coli or C. albicans [22][23][24], and in the reduction of the bacterial pathogens' adhesion to voice prostheses or silicone rubber [25], have also been reported.…”

Potential Food Application of a Biosurfactant Produced by Saccharomyces cerevisiae URM 6670

“…Biosurfactants are molecules of biological origin (e.g., microorganisms) capable of reducing the surface and interfacial tensions. The surfactant activity of these natural compounds is due to the existence of both hydrophilic and hydrophobic moieties in the molecular structure (Rane et al, 2017;López-Prieto et al, 2019). Biosurfactants have aroused considerable interest in recent decades due to their advantageous properties over synthetic surfactants, such as high selectivity and biodegradability, stability in a range of environmental conditions (temperature, pH, and salinity), and low toxicity, favoring their application in the recovery of hydrophobic compounds and as emulsifiers in the pharmaceutical, cosmetic, and food industries (Garg and Priyanka, 2018;Felix et al, 2018).…”