Identification and characterization of plantaricin Q7, a novel plantaricin produced by Lactobacillus plantarum Q7

Abstract

As consumer trends shift toward natural preservatives, it is becoming increasingly necessary to identify antimicrobials that can be used in food products to decrease proliferation of spoilage and pathogenic bacteria. The data presented identifies a novel plantaricin Q7. Lactic acid bacterial strains were isolated from food and of the 118 colonies that were screened, only one produced an inhibitory effect against Pseudomonas fluorescens AS 1.1802. Molecular and biochemical methods indicated this bacterium was Lactobacillus plantarum. Plantaricin Q7 was purified by absorption-desorption, CM-Fast Flow and Superdex Peptide 10/300 GL. Plantaricin Q7 became inactive following treatment with proteolytic enzyme, including proteinase K, pepsin, trypsin, papain, and pronase E. The plantaricin Q7 remained active following incubation at 121 o C for 20 min and following incubation pH ranging from 3.0-12.0 for 30 min. Pseudomonas. putida AS1.1819, Pseudomonas. aeruginosa CICC21636 , Listeria monocytogenes ATCC19111, Escherichia coli AT CC25922, Salmonella typhimurium ATCC14028, Staphylococcus aureus, Shigella flexneri ATCC12022 and Shigella sonnei ATCC25931 were all sensitive to plantaricin Q7. The data presented suggests plantaricin Q7 can be applied to food products to inhibit the growth of numerous food spoilage bacteria and pathogens.

Adsorption of plantaricin Q7 on montmorillonite and application in feedback regulation of plantaricin Q7 synthesis by Lactobacillus plantarum Q7

“…These results are in agreement with Ibarguren [8,25]. Previously our laboratory discovered that plantaricin Q7 is a cationic peptide, which consisting of 40 amino acids including seven lysine, five arginine and two histidine residues [11]. 4C 1 and C 2 .…”

“…Clay may allow a controlled release of antimicrobial peptides and are regarded as safe food carriers and additives by US Food and Drug Administration and European Food Safety Authority [8]. Plantaricin Q7, a novel bacteriocin produced by Lactobacillus plantarum Q7, with a broad anti-microbial activity against Gram-positive and Gram-negative food-associated pathogens such as Listeria monocytogenes, Staphylococcus aureus, Pseudomonas fluorescen and Escherichia coli, had been reported by our group [11]. Plantaricin Q7, a novel bacteriocin produced by Lactobacillus plantarum Q7, with a broad anti-microbial activity against Gram-positive and Gram-negative food-associated pathogens such as Listeria monocytogenes, Staphylococcus aureus, Pseudomonas fluorescen and Escherichia coli, had been reported by our group [11].…”

“…The plantaricin Q7 producer L. plantarum Q7 was isolated and identified previously from Yak milk yoghurt in Qinghai, China [11], and stored at -20°C in MRS broth containing 20% (v/v) glycerol. L. monocytogenes (preserved in the Harbin Institute of Technology) was used as an indicator strain and was stored at -20°C in brain heart infusion broth (Qingdao Hope Bio Technology Co., Ltd., Shandon, China) containing 20% (v/v) glycerol.…”

“…Standard nisin solutions of 3000, 2500, 2000, 1500, 1000, 750, 500, 375, 250, 125, 62.5 and 0 IU/mL were prepared using the 3000 IU/mL nisin stock solution and utilized to construct the standard curve [11,19]. A stock nisin solution was prepared by adding 0.030 g commercial nisin (Aladdin Shanghai Biochemical Technology Co., Ltd., Shanghai, China) to 10 mL of sterile ddH 2 O .…”

“…Nonetheless, only nisin and pediocin were researched for adsorption into clays [9,10]. Plantaricin Q7, a novel bacteriocin produced by Lactobacillus plantarum Q7, with a broad anti-microbial activity against Gram-positive and Gram-negative food-associated pathogens such as Listeria monocytogenes, Staphylococcus aureus, Pseudomonas fluorescen and Escherichia coli, had been reported by our group [11]. Although plantaricin Q7 showed good thermal and pH stability, anti-microbial activity was reduced by interactions with food components, such as proteases [11].…”