Antimicrobial Activity of a Synthetic Bacteriocin Found in the Genome of Lactobacillus Casei on the Microbiota of Antioquian Soft Cheese (Quesito Antioqueño)

Abstract

Background: Lactic Acid Bacteria (LAB) are of special interest in the food industry due to their ability to produce metabolites. Among them, bacteriocins, which can inhibit the growth of altering microorganisms, and pathogens in a wide variety of foods, are considered safe for human consumption and are used as preservatives. Objectives: Evaluate the effect of a bacteriocin found by in silico methods on the microbiota present in Antioquian soft cheese. Methods: In this research, we design a synthetic bacteriocin, called Bac 22, found in the genome of Lactobacillus casei using the genomic mining methodology and bioinformatics tools. We also conducted a preliminary biological and hemolytic activities studies of the Bac 22 toward the microbiota present in the Antioquian soft cheese (Quesito Antioqueño). Results: The bacteriocin Bac 22 at a concentration of 100 μM presented a hemolytic capacity lower than 1% and reduced the CFU / g of total coliforms significantly when added to Antioquian soft cheese for eight days. Conclusions: The Bac 22 demonstrated a positive potential effect over the shelf life of a dairy product, such as the Antioquian soft cheese.

Isolation, Characterization, and Effect on Biofilm Formation of Bacteriocin Produced by Lactococcus lactis F01 Isolated from Cyprinus carpio and Application for Biopreservation of Fish Sausage

“…However, at a concentration of 10 μ g/ml, the percentage of hemolysis is almost zero of which 0.7 ± 0.0029% is almost equal to that of nisin at the same concentration. These results are in agreement with those reported by [ 32 , 55 ].…”

“…The hemolytic activity of the bacteriocin was tested on chicken erythrocytes by the method of [ 32 ]. The erythrocytes were separated by centrifugation at 1,000 g for 5 min.…”

Evaluation of Lactic Acid Bacteria (LAB) against Shigella sonnei ATCC 25931

“…It is very useful to know that the LAB isolated from products from Southern Colombia presented an inhibitory effect against the reference pathogen, evincing the viability of these strains under different conditions. For example, the coffee strains at different times of fermentation (D and L), the quesillo strain isolated characterized as psychrophilic (12) and the strain isolated from mother's milk, whereby according to the mother, her child did not develop any illnesses during the whole period of breastfeeding. This supports Hippocrates' statement "Let your food be your medicine and your medicine be your food.…”

“…LAB are characterized by the production of antimicrobial substances (lactic and acetic acids, metabolites), [11] and bacteriocins, which are a family of antimicrobial peptides produced by bacteria through ribosomal synthesis that can act as helper peptides for probiotic strains in the gastrointestinal tract [12]. Given these properties, the UN Food and Agriculture Organization (FAO) and the World Health Organization (WHO) have defined probiotics as "living microorganisms which, when administered in appropriate doses, confer beneficial effects on the health of the consumer" [13].…”