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

Abstract

The aim of this work was the screening of bacteriocin-producing LABs isolated from fish, the selection of promising/prominent strain(s), the characterization of the bacteriocin produced, and the evaluation of its potential to be used as biopreservative(s). Amplification and sequencing of the 16S rRNA gene of the bacteriocin-producing strain was performed. Then a partial purification of the produced bacteriocin, using a combination of ammonium sulfate and chloroform-methanol precipitation, was done. Its molecular weight was determined by SDS-PAGE. In addition, the action spectrum, the hemolysis test, and its ability to inhibit biofilm formation were analyzed. A total of 88 isolates of lactic acid bacteria (LAB) including one bacteriocin producer, which was identified as Lactococcus lactis F01, were collected. The bacteriocin was partially purified with an estimated yield of 40%. Regarding the SDS-PAGE profile, the secreted bacteriocin has molecular weight of about 3.5 kDa and was identified as class I bacteriocin. The antimicrobial test showed that the bacteriocin inhibits pathogenic and/or spoilage bacteria, 10 Gram-positive and 16 Gram-negative bacterial species. Moreover, it can inhibit biofilm formation from 1.3% (Escherichia coli) to 63.92% (Pseudomonas aeruginosa ATCC15692) depending on the strain. The hemolytic activity of novel bacteriocin was observed at the concentration of 10 μg/ml of bacteriocin crude extract, which was 0.7 ± 0.0029 % . In addition, it exhibited good thermal and pH stability with retained antibacterial activity of 85.25% after treatment at 121°C for 20 min, as well as at a pH range between 2.0 and 10.0. Moreover, this bacteriocin showed the ability to inhibit the growth of bacterial culture load in fish sausage stored at 8°C for 28 days. Considering the results obtained, bacteriocin could be potentially exploited as an alternative to chemical preservatives or as a substitute for antibiotics.

Plantaricin LD1 Inhibits the Growth and Biofilm Formation of Staphylococcus aureus in Milk

“…47 Plantaricin 827 from L. plantarum 163 and bacteriocin C4B from L. lactis F01 inhibited the biofilm formation of S. aureus ATCC 25923, ATCC 43300 and ATCC 35395, respectively. 40, 48 Milk is rich in macro and micronutrients and therefore it is a suitable medium for the growth of pathogenic bacteria. 49 S. aureus contamination in food has led to a significant need in the food industry for natural, secure and efficient antimicrobial agents that are capable of inactivating pathogenic bacteria from food.…”

Technological properties and genetic profile of lactic acid bacteria isolated from Cameroonian tropical fruits

“…Lactic acid bacteria are very common in nature and occupy a variety of ecological niches. Milk, fermented milk products, meat, digestive tract of animals and traditional fermented drinks have been the subject of isolation of LAB with exploitable technological properties and others used as probiotics [4,[7][8][9][10][11]. Just like the aforementioned niches, tropical fruits (pineapple, papaya, orange and banana) provide a favourable environment for the development of microorganisms [1].…”