Technological and safety properties of bacteriocin-producing Enterococcus strains isolated from traditional Turkish cheeses

Main Article Content

Didem Akpınar Kankaya

Keywords

bacteriocin, cheese, enterococci, safety assessment, technological property

Abstract


The aim of this study was to identify bacteriocin-producing lactic acid bacteria (LAB) isolated from traditional Turkish cheeses, evaluate their antibacterial properties and technological characteristics, and determine the safety properties of isolates. The isolated strains were identified as Enterococcus faecium DP8.3, DP9.3, and Enterococcus mundtii DP35.1, which are genetically different from each other. The bacteriocins produced by these isolates exhibited stability under high temperatures and maintained their antibacterial activity across a broad pH spectrum. The bacterial strains were fast acid producers, lacked proteolytic or lipolytic activity, were susceptible to antibiotics, and did not show antibiotic resistance or virulence genes. In addition, all the Enterococcus strains decarboxylated tyrosine and showed tdc gene expression. According to the technological properties and safety assessment of the strains, it is believed that they can be used as protective adjunct cultures in the food industry.


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References

Aguilar-Galvez, A., Dubois-Dauphin, R., Campos, D., and Thonart, P. 2011. Genetic determination and localization of multiple bacteriocins produced by Enterococcus faecium CWBI-B1430 and Enterococcus mundtii CWBI-B1431. Food Science and Biotechnology 20: 289–296. 10.1007/s10068-011-0041-6

Akpınar Kankaya, D., and Tuncer, Y. 2020. Antibiotic resistance in vancomycin-resistant lactic acid bacteria (VRLAB) isolated from foods of animal origin. Journal of Food Processing and Preservation 44(6): e14468. 10.1111/jfpp.14468

Akpınar Kankaya, D., and Tuncer, Y. 2022. Detection of virulence factors, biofilm formation, and biogenic amine production in vancomycin-resistant lactic acid bacteria (VRLAB) isolated from foods of animal origin. Journal of Food Processing and Preservation 46(4): e16423. 10.1111/jfpp.16423

Almeida-Santos, A. C., Novais, C., Peixe, L., and Freitas, A. R. 2021. Enterococcus spp. as a producer and target of bacteriocins: A double-edged sword in the antimicrobial resistance crisis context. Antibiotics 10: 1215. 10.3390/antibiotics10101215

Altınkaynak, T., and Tuncer, Y. 2020. Fermente sucuktan izole edilen antilisterial Enterococcus mundtii YB6.30 tarafından üretilen bakteriyosinin karakterizasyonu. Gıda 45: 963–976. 10.15237/gida.GD20081

Aslam, M., Shahid, M., Rehman, F. U., Naveed, N. H., Batool, A. I., Sharif, S., et al. 2011. Purification and characterization of bacteriocin isolated from Streptococcus thermophilus. African Journal of Microbiology Research 5(18): 2642–2648. 10.5897/AJMR11.225

Avcı, M., and Özden Tuncer, B. 2017. Safety evaluation of enterocin producer Enterococcus sp. strains isolated from traditional Turkish Cheeses. Polish Journal of Microbiology 66(2): 223–233. 10.5604/01.3001.0010.7839

Bagci, U., Ozmen Togay, S., Temiz, A., and Ay, M. 2019. Probiotic characteristics of bacteriocin-producing Enterococcus faecium strains isolated from human milk and colostrum. Folia Microbiologica 64: 735–750. 10.1007/s12223-019-00687-2

Barbieri, F., Montanari, M., Gardini, F., and Tabanelli, G. 2019. Biogenic amine production by lactic acid bacteria: A Review. Foods 8(1): 17. 10.3390/foods8010017

Belgacem, Z. B., Abriouel, H., Omar, N. B., Lucas, R., Martínez-Canamero, M., Gálvez, A., et al. 2010. Antimicrobial activity, safety aspects, and some technological properties of bacteriocinogenic Enterococcus faecium from artisanal Tunisian fermented meat. Food Control 21(4): 462–470. 10.1016/j.foodcont.2009.07.007

Ben Braïek, O., Morandi, S., Cremonesi, P., Smaoui, S., Hani, K., and Ghrairi, T. 2018. Safety, potential biotechnological and probiotic properties of bacteriocinogenic Enterococcus lactis strains isolated from raw shrimps. Microbial Pathogenesis 117: 109–117. 10.1016/j.micpath.2018.02.021

Ben Braïek, O., Smaoui, S., Ennouri, K., Morandi, S., Cremonesi, P., Hani, K., et al. 2019. RAPD-PCR characterisation of two Enterococcus lactis strains and their potential on Listeria monocytogenes growth behaviour in stored chicken breast meats: Generalised linear mixed-effects approaches. LWT-Food Science and Technology 99: 244–253. 10.1016/j.lwt.2018.09.053

Bover-Cid, S., and Holzapfel, W. H. 1999. Improved screening procedure for biogenic amine production by lactic acid bacteria. International Journal of Food Microbiology 53(1): 33–41. 10.1016/S0168-1605(99)00152-X

Bradley, R. L., Arnold, E., Barbano, D. M., Semerad, R. G., Smith, D. E., and Vines B. K. 1992. Chemical and physical methods. Standard methods for the examination of dairy products 16: 433–531.

Cancilla, M. R., Powell, I. B., Hillier, A. J., and Davidson, B. E. 1992. Rapid genomic fingerprinting of Lactococcus lactis strains by arbitrarily primed polymerase chain reaction with 32P and fluorescent labels. Applied and Environmental Microbiology 58(5): 1772–1775. 10.1128/aem.58.5.1772-1775.1992

Cavicchioli, V. Q., Camargo, A. C., Todorov, S. D., and Nero, L. A. 2017. Novel bacteriocinogenic Enterococcus hirae and Pediococcus pentosaceus strains with antilisterial activity isolated from Brazilian artisanal cheese. Journal of Dairy Science 100(4): 2526–2535. 10.3168/jds.2016-12049

Chaje¸cka-Wierzchowska, W., Zadernowska, A., and Łniewska-Trokenheim,. 2016. Virulence factors, antimicrobial resistance and biofilm formation in Enterococcus spp. isolated from retail shrimps. LWT–Food Science and Technology 69: 117–122. 10.1016/j.lwt.2016.01.034

Chaje¸cka-Wierzchowska, W., Zadernowska, A., and Łniewska-Trokenheim, Ł. 2017. Virulence factors of Enterococcus spp. presented in food. Lebensmittel-Wissenschaft & Technologie 75: 670–676. 10.1016/j.lwt.2016.10.026

Clinical and Laboratory Standards Institute (CLSI). 2016. Performance standards for antimicrobial susceptibility testing, twenty-six informational supplement. M100-S26, Wayne, PA.

Cocolin, L., Dolci, P., Rantsiou, K., Urso, R., Cantoni, C., and Comi, G. 2009. Lactic acid bacteria ecology of three traditional fermented sausages produced in the north of Italy as determined by molecular methods. Meat Science 82(1): 125–132. 10.1016/j.meatsci.2009.01.004

De Las Rivas, B., Marcobal, A., Carrascosa, A. V., and Munoz, R. 2006. PCR detection of foodborne bacteria producing the biogenic amines histamine, tyramine, putrescine and cadaverine. Journal of Food Protection 69: 2509–2514. 10.4315/0362-028X-69.10.2509

Demirgül, F., and Tuncer, Y. 2017. Detection of antibiotic resistance and resistance genes in enterococci isolated from sucuk, a traditional Turkish dry-fermented sausage. Korean Journal for Food Science of Animal Resources 37(5): 670–681. 10.5851/kosfa.2017.37.5.670

Depardieu, F., Perichon, B., and Courvalin, P. 2004. Detection of the van alphabet and identification of enterococci and staphylococci at the species level by multiplex PCR. Journal of Clinical Microbiology 42(12): 5857–5860. 10.1128/jcm.42.12.5857-5860.2004

Dutka-Malen, S., Evers, S., and Courvalin, P. 1995. Detection of glycopeptide resistance genotypes and identification to the species level of clinically relevant enterococci by PCR. Journal of Clinical Microbiology 33(1): 24–27. 10.1128/jcm.33.1.24-27.1995

Eaton, T. J., and Gasson, M. J. 2001. Molecular screening of Enterococcus virulence determinants and potential for genetic exchange between food and medical isolates. Applied and Environmental Microbiology 67(4): 1628–1635. 10.1128/AEM.67.4.1628-1635.2001

Edwards, U., Rogall, T., Blöcker, H., Emde, M., and Böttger, E. C. 1989. Isolation and direct complete nucleotide determination of entire genes. Characterization of a gene coding for 16S ribosomal RNA. Nucleic Acids Research 17(19): 7843–7853. 10.1093/nar/17.19.7843

Erginkaya, Z., Turhan, E. U., and Tatlı, D. 2018. Determination of antibiotic resistance of lactic acid bacteria isolated from traditional Turkish fermented dairy products. Iranian Journal of Veterinary Research 19(1): 53–56. PMCID: PMC5960774; PMID 29805464

EUCAST. 2021. European Committee on Antimicrobial Susceptibility Testing. Breakpoint tables for interpretation of MICs and zone diameters. Version 11.0, valid from 2021-01-01. Evolutionary Microbiology 67(12): 5216–5221. https://www.eucast.org/clinical_breakpoints/EvolutionaryMicrobiology

Fontana, C., Cocconcelli, P. S., Vignolo, G., and Saavedra, L. 2015. Occurrence of antilisterial structural bacteriocins genes in meat borne lactic acid bacteria. Food Control 47: 53–59. 10.1016/j.foodcont.2014.06.021

Franz, C. M. A. P., Du Toit, M., Von Holy, A., Schillinger, U., and Holzapfel, W. H. 1997. Production of nisin-like bacteriocins by Lactococcus lactis strains isolated from vegetables. Journal of Basic Microbiology 37(3): 187–196. 10.1002/jobm.3620370307

Gök Charyyev, M., Özden Tuncer, B., Akpınar Kankaya, D., and Tuncer, Y. 2019. Bacteriocinogenic properties and safety evaluation of Enterococcus faecium YT52 isolated from boza, a traditional cereal based fermented beverage. Journal of Consumer Protection and Food Safety 14: 41–53. 10.1007/s00003-019-01213-9

Graham, K., Stack, H., and Rea, R. 2020. Safety, beneficial and technological properties of enterococci for use in functional food applications–A review. Critical Reviews in Food Science and Nutrition 60(22): 3836–3861. 10.1080/10408398.2019.1709800

Güley, Z., Fallico, Z., Cabrera-Rubio, R., O’Sullivan, D., Marotta, M., Pennone, V., et al. 2023. Diversity of the microbiota of traditional Izmir Tulum and Izmir brined Tulum cheeses and selection of potential probiotics. Foods 12(18): 3482. 10.3390/foods12183482

Haghshenas, B., Haghshenas, M., Nami, Y., Khosroushahi, A. Y., Abdullah, N., Barzegari, A., et al. 2016. Probiotic assessment of Lactobacillus plantarum 15HN and Enterococcus mundtii 50H isolated from traditional dairies microbiota. Advanced Pharmaceutical Bulletin 6(1): 37–47. 10.15171/apb.2016.07

Heras, J., Domínguez, C., Mata, E., Pascual, V., Lozano, C., Torres, C., et al. 2015. GelJ-A tool for analyzing DNA fingerprint Gel Images. BMC Bioinformatics 16(1): 1–8. 10.1186/s12859-015-0703-0

Iseppi, R., Stefani, S., de Niederhausern, S., Bondi, M., Sabia, C., and Messi, P. 2019. Characterization of anti-Listeria monocytogenes properties of two bacteriocin-producing Enterococcus mundtii isolated from fresh fish and seafood. Current Microbiology 76: 1010–1019. 10.1007/s00284-019-01716-6

Jackson, C. R., Fedorka-Cray, P. J., and Barrett, J. B. 2004. Use of a genus-and species-specific multiplex PCR for identification of enterococci. Journal of Clinical Microbiology 42(8): 3558–3565. 10.1128/jcm.42.8.3558-3565.2004

Jaouani, I., Abbassi, M. S., Ribeiro, S. C., Khemiri, M., Mansouri, R., Messadi, L., et al. 2015. Safety and technological properties of bacteriocinogenic enterococci isolates from Tunisia. Journal of Applied Microbiology 119: 1089–1100. 10.1111/jam.12916

Johnson, E. M., Jung, Y. G., Jin, Y. Y., Jayabalan, R., Yang, S. H., and Suh, J. W. 2018. Bacteriocins as food preservatives: Challenges and emerging horizons. Critical Reviews in Food Science and Nutrition 58: 2743–2767. 10.1080/10408398.2017.1340870

Kaškonienė, V., Stankevičius, M., Bimbiraitė-Survilienė, K., Naujokaitytė, G., Šernienė, L., Mulkytė, K., et al. 2017. Current state of purification, isolation and analysis of bacteriocins produced by lactic acid bacteria. Applied Microbiology and Biotechnology 101: 1323–1335. 10.1007/s00253-017-8088-9

Khalkhali, S., and Mojgani, N. 2017. Bacteriocinogenic potential and virulence traits of Enterococcus faecium and E. faecalis isolated from human milk. Iranian Journal of Microbiology 9(4): 224–233. PMCID: PMC5723975; PMid: 29238458.

Ladero, V., Fernández, M., Calles-Enríquez, M., Sánchez Llana, E., Cañedo, E., Martin, M. C., et al. 2012. Is the production of the biogenic amines tyramine and putrescine a species-level trait in enterococci? Food Microbiology 30: 132–138. 10.1016/j.fm.2011.12.016

Landeta, G., Curiel, J. A., Carrascosa, A. V., Muñoz, R., and De las Rivas, B. 2013. Technological and safety properties of lactic acid bacteria isolated from Spanish dry-cured sausages. Meat Science 95(2): 272–280. 10.1016/j.meatsci.2013.05.019

Lemcke, R., and Bülte, M. 2000. Occurrence of the vancomycin-resistant genes vanA, vanB, vanC1, vanC2 and vanC3 in Enterococcus strains isolated from poultry and pork. International Journal of Food Microbiology 60(2–3): 185–194. 10.1016/S0168-1605(00)00310-X

Marcobal, A., De Las Rivas, B., Landete, J. M., Tabera, L., and Muñoz, R. 2012. Tyramine and phenylethylamine biosynthesis by food bacteria. Critical Reviews in Food Science and Nutrition 52: 448–467. 10.1080/10408398.2010.500545

Martín, B., Garriga, M., Hugas, M., Bover-Cid, S., Veciana-Nogués, M. T., and Aymerich, T. 2006. Molecular, technological and safety characterization of Gram-positive catalase-positive cocci from slightly fermented sausages. International Journal of Food Microbiology 107(2): 148–158. 10.1016/j.ijfoodmicro.2005.08.024

Mathur, S., and Singh, R. 2005. Antibiotic resistance in food lactic acid bacteria–A review. International Journal of Food Microbiology 105: 281–295. 10.1016/j.ijfoodmicro.2005.03.008

Moraes, P. M., Perin, L. M., Todorov, S. D., Silva, A., Franco, B. D. G. M., and Nero, L. A. 2012. Bacteriocinogenic and virulence potential of Enterococcus isolates obtained from raw milk and cheese. Journal of Applied Microbiology 113(2): 318–328. 10.1111/j.1365-2672.2012.05341.x

Müller, D. M., Carrasco, M. S., Tonarelli, G. G., and Simonetta, A. C. 2009. Characterization and purification of a new bacteriocin with a broad inhibitory spectrum produced by Lactobacillus plantarum lp 31 strain isolated from dry-fermented sausage. Journal of Applied Microbiology 106(6): 2031–2040. 10.1111/j.1365-2672.2009.04173.x

Nami, Y., Bakhshayesh, R. V., Jalaly, H. M., Lotfi, H., Eslami, S., and Hejazi, M. A. 2019. Probiotic properties of Enterococcus isolated from artisanal dairy products. Frontiers in Microbiology 10: 300. 10.3389/fmicb.2019.00300

Niu, H., Yu, H., Hu, T., Tian, G., Zhang, L., Guo, X., et al. 2016. The prevalence of aminoglycoside-modifying enzyme and virulence genes among enterococci with high-level aminoglycoside resistance in inner Mongolia, China. Brazilian Journal of Microbiology 47(3): 691–696. 10.1016/j.bjm.2016.04.003

O’Connor, P. M., Kuniyoshi, T. M., Oliveira, R. P., Hill, C., Ross, R. P., and Cotter, P. D. 2020. Antimicrobials for food and feed: A bacteriocin perspective. Current Opinion in Biotechnology 61: 160–167. 10.1016/j.copbio.2019.12.023

Ouoba, L. I. I., Lei, V., and Jensen, L. B. 2008. Resistance of potential probiotic lactic acid bacteria and bifidobacteria of African and European origin to antimicrobials: Determination and transferability of the resistance genes to other bacteria. International Journal of Food Microbiology 121: 217–224. 10.1016/j.ijfoodmicro.2007.11.018

Özden Tuncer, B., Ay, Z., and Tuncer, Y. 2013. Occurrence of enterocin genes, virulence factors, and antibiotic resistance in 3 bacteriocin-producer Enterococcus faecium strains isolated from Turkish Tulum Cheese. Turkish Journal of Biology 37(4): 443–449. 10.3906/biy-1209-26

Özkalp, B., Özden, B., Tuncer, Y., Şanlıbaba, P., and Akçelik, M. 2007. Technological characterization of wild-type Lactococcus lactis strains isolated from raw milk and traditional fermented milk products in Turkey. Le Lait 87: 521–534. 10.1051/lait:2007033

Öztürk, H., Geniş, B., Özden Tuncer, B., and Tuncer, Y. 2023. Bacteriocin production and technological properties of Enterococcus mundtii and Enterococcus faecium strains isolated from sheep and goat colostrum. Veterinary Research Communications 47(3): 1321–1345. 10.1007/s11259-023-10080-7

Qiao, X., Du, R., Wang, Y., Han, Y., and Zhou, Z. 2020. Isolation, characterisation and fermentation optimisation of bacteriocin-producing Enterococcus faecium. Waste and Biomass Valorization 11: 3173–3181. 10.1007/s12649-019-00634-9

Reviriego, C., Eaton, T., Martín, R., Jiménez, E., Fernández, L., Gasson, M. J., et al. 2005. Screening of virulence determinants in Enterococcus faecium strains isolated from breast milk. Journal of Human Lactation., 21(2): 131–137. 10.1177/0890334405275394

Rocha, P. A. B., Marques, J. M. M., Barreto, A. S., and Semedo-Lemsaddek, T. 2022. Enterococcus spp. from Azeitão and Nisa PDO-cheeses: Surveillance for antimicrobial drug resistance. LWT-Food Science and Technology 154: 112622. 10.1016/j.lwt.2021.112622

Rossetti, L., and Giraffa, G. 2005. Rapid identification of dairy lactic acid bacteria by M13-generated, RAPD-PCR fingerprint databases. Journal of Microbiological Methods 63(2): 135–144. 10.1016/j.mimet.2005.03.001

Ryan, M. P., Rea, M. C., Hill, C., and Ross, R. P. 1996. An application in Cheddar Cheese manufacture for a strain of Lactococcus lactis producing a novel broad-spectrum bacteriocin, lacticin 3147. Applied and Environmental Microbiology 62(2): 612–619. 10.1128/aem.62.2.612-619.1996

Sağlam, H., and Türkmen, F. U. 2022. Determination of probiotic and some technological properties of lactic acid bacteria isolated from cheeses sold in the Kilis region, Turkey. Mustafa Kemal Üniversitesi Tarım Bilimleri Dergisi 27(1): 9–17. 10.37908/mkutbd.982711

Sahoo, T. K., Jena, P. K., Nagar, N., Patel, A. K., and Seshadri, S. 2015. In vitro evaluation of probiotic properties of lactic acid bacteria from the gut of labeo rohita and catla catla. Probiotics and Antimicrobial Proteins 7(2): 126–136. 10.1007/s12602-015-9184-8

Schelegueda, L. I., Vallejo, M., Gliemmo, M. F., Marguet, E. R., and Campos, C. A. 2015. Synergistic antimicrobial action and potential application for fish preservation of a bacteriocin produced by Enterococcus mundtii isolated from Odontesthes platensis. LWT–Food Science and Technology 64: 794–801. 10.1016/j.lwt.2015.06.017

Settanni, L., Guarcello, R., Gaglio, R., Francesco, N., Aleo, A., Felis, G. E., et al. 2014. Production, stability, gene sequencing and in situ anti-Listeria activity of mundticin KS expressed by three Enterococcus mundtii strains. Food Control 35(1): 311–322. 10.1016/j.foodcont.2013.07.022

Sonsa-Ard, N., Rodtong, S., Chikindas, M. L., and Yongsawatdigul, J. 2015. Characterization of bacteriocin produced by Enterococcus faecium CN-25 isolated from traditionally Thai fermented fish roe. Food Control 54: 308–316. 10.1016/j.foodcont.2015.02.010

Toplu, M. S., and Özden Tuncer, B. 2023. Evaluation of the functional properties and safety of enterocin-producing Enterococcus faecium BT29.11 isolated from Turkish Beyaz Cheese and its inhibitory activity against Listeria monocytogenes in UHT whole milk. Italian Journal of Food Science 35(2): 54–70. 10.15586/ijfs.v35i2.2316

Urban-Chmiel, R., Marek, A., Stępień-Pyśniak, D., Wieczorek, K., Dec, M., Nowaczek, A., et al. 2022. Antibiotic resistance in bacteria–A review. Antibiotics 11(8): 1079 10.3390/antibiotics11081079.

Vakulenko, S. B., Donabedian, S. M., Voskresenskiy, A. M., Zervos, M. J., Lerner, S. A., Chow, J. W. 2003. Multiplex PCR for detection of aminoglycoside resistance genes in enterococci. Antimicrobial Agents and Chemotherapy 47(4): 1423–1426. 10.1128/aac.47.4.1423-1426.2003

Valledor, S. J. D., Bucheli, J. E. V., Holzapfel, W. H., and Todorov, S. D. 2020. Exploring beneficial properties of the bacteriocinogenic Enterococcus faecium ST10Bz strain isolated from Boza, a Bulgarian cereal-based beverage. Microorganisms 8(10): 1474. 10.3390/microorganisms8101474

Valledor, S. J. D., Dioso, C. M., Bucheli, J. E. V., Park, Y. J., Suh, D. H., Jung, E. S., et al. 2022. Characterization and safety evaluation of two beneficial, enterocin-producing Enterococcus faecium strains isolated from kimchi, a Korean fermented cabbage. Food Microbiology 102: 103886. 10.1016/j.fm.2021.103886

Van Belkum, M. J., Hayema, B. J., Geis, A., Kok, J., and Venema, G. 1989. Cloning of two bacteriocin genes from a lactococcal bacteriocin plasmid. Applied and Environmental Microbiology 55(5): 1187–1191. 10.1128/aem.55.5.1187-1191.1989

Vankerckhoven, V., Van Autgaerden, T., Vael, C., Lammens, C., Chapelle, S., Rossi, R., et al. 2004. Development of a multiplex PCR for the detection of asaI, gelE, cylA, esp, and hyl genes in enterococci and survey for virulence determinants among European hospital isolates of Enterococcus faecium. Journal of Clinical Microbiology 42(10): 4473–4479. 10.1128/jcm.42.10.4473-4479.2004

Vimont, A., Fernandez, B., Hammami, R., Ababsa, A., Daba, H., and Fliss, I. 2017. Bacteriocin-producing Enterococcus faecium LCW 44: A high potential probiotic candidate from raw camel milk. Frontiers in Microbiology 8: 865. 10.3389/fmicb.2017.00865

Yalçın, M., Özden Tuncer, B., Akpınar Kankaya, D., and Tuncer, Y. 2023. Presence of genes encoding aminoglycoside-modifying enzyme (AME) and virulence factors in high-level aminoglycoside-resistant (HLAR) Enterococcus strains isolated from retail chicken meat in Turkey. Journal of the Hellenic Veterinary Medical Society 74(4): 6441–6450. 10.12681/jhvms.30850

Yi, L., Qi, T., Hong, Y., Deng, L., and Zeng, K. 2020. Screening of bacteriocin-producing lactic acid bacteria in Chinese homemade pickle and dry-cured meat, and bacteriocin identification by genome sequencing. LWT–Food Science and Technology 125: 109177. 10.1016/j.lwt.2020.109177

Yousif, N. M. K., Dawyndt, P., Abriouel, H., Wijaya, A., Schillinger, U., Vancanneyt, M., et al. 2005. Molecular characterization, technological properties and safety aspects of enterococci from “Hussuwa”, an African fermented sorghum product. Journal of Applied Microbiology 96: 216–228. 10.1111/j.1365-2672.2004.02450.x

Zendo, T., Eungruttanagorn, N., Fujioka, S., Tashiro, Y., Nomura, K., Sera, Y., et al. 2005. Identification and production of a bacteriocin from Enterococcus mundtii QU2 isolated from soybean. Journal of Applied Microbiology 99:1181–1190. 10.1111/j.1365-2672.2005.02704.x