Nisin Z-Producing Lactococcus lactis Subsp. Lactis  GYl32 Isolated from Boza

Abstract

In this study, bacteriocin‐producing Lactococcus lactis subsp. lactis GYL32 strain was isolated from Boza. The GYL32 strain inhibited not only related strains but also gram‐positive bacteria, such as Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus. The antimicrobial substance was inactivated after treatment with proteinase K and α‐chymotrypsin but not other enzymes. Bacteriocin remained active after 2 h of incubation at pH 2–11. It was stable to heat after treatment at 100C for 20 min. The bacteriocin produced by GYL32 was characterized as nisin by different pH, enzyme and heat treatments. The sequence analysis result showed that it is nisin Z, and its genetic determinants are encoded on genomic DNA. The maximum antimicrobial activity (5,120 AU/mL) was recorded after 8 h in M17 broth. Tricine‐SDS‐PAGE analysis showed that its molecular weight 6,700 Da. L. lactis subsp. lactis GYL32 strain may be used as a protective culture for manufacturing fermented products. Practical Applications Nisin is the best‐studied bacteriocin produced by some Lactococcus lactis strains and has been used for food preservation in over 50 countries. The present study describes isolation and characterization of nisin Z‐producing L. lactis strain isolated from traditional cereal‐based fermented food, which is Boza from Turkey. The results of this study suggest that nisin Z producer L. lactis subsp. lactis GYL32 strain may be used as a starter culture for improving the food safety of the fermented products.

Safety assessment, genetic relatedness and bacteriocin activity of potential probiotic Lactococcus lactis strains from rainbow trout (Oncorhynchus mykiss, Walbaum) and rearing environment

“…Downstream the NisZ gene cluster of L. cremoris WA2-67, two transposases showing homology with the lactococcal insertion sequence IS981 [68] were identified, which together with the sucrose operon constitutes a large nisin-sucrose conjugative transposon (Tn5276) [69]. NisZ-producing L. lactis strains are highly widespread in nature and have been isolated from several sources, including the intestine of the marine fish olive flounder (Paralichthys olivaceus) [70], fermented foods such as cheese [71], dahi (homemade fermented milk) [72], kimchi (Korean fermented vegetables) [73], nham (traditional Thai fermented sausage) [74], boza (cereal-based fermented beverage) [75], rice noodles [76], bean sprouts [77] and human stools [78]. Among the other known nisin variants, nisin F is the only one produced by a L. lactis strain of fish origin, namely freshwater catfish (Clarias gariepinus) [79].…”

Metabiotics Signature through Genome Sequencing and In Vitro Inhibitory Assessment of a Novel Lactococcus lactis Strain UTNCys6-1 Isolated from Amazonian Camu-Camu Fruits

“…Under these experimental conditions, the size was larger than that of Lactococcus nisin-producer strains, suggesting that extra molecules could associate into a larger complex compound. An early study showed that L. lactis strain GLY32 isolated from boza produced a bacteriocin of 6.7 kDa [ 48 ]. Likewise, in this study, the molecular size of commercial nisin was about 10 kDa on SDS-PAGE.…”

Pastırmadaki Potansiyel Bakteriyosinojenik Laktik Asit Bakterileri

“…Known bacteriocinogenic strain Lactococcus lactis subsp. lactis GYL32 was used as the positive control (Koral and Tuncer, 2014). These LAB isolates and the standard bacteriocin producer strain were grown in de Man, Rogosa and Sharpe (MRS) broth or on MRS agar at 30 °C under unaerobic conditions.…”