title: Molecular characterisation of new organisation of plnEF and plw loci of bacteriocin genes harbour concomitantly in Lactobacillus plantarum I-UL4.
abstract: BACKGROUND
  Bacteriocin-producing Lactic acid bacteria (LAB) have vast applications in human and animal health, as well as in food industry. The structural, immunity, regulatory, export and modification genes are required for effective bacteriocin biosynthesis. Variations in gene sequence, composition and organisation will affect the antimicrobial spectrum of bacteriocin greatly. Lactobacillus plantarum I-UL4 is a novel multiple bacteriocin producer that harbours both plw and plnEF structural genes simultaneous which has not been reported elsewhere. Therefore, molecular characterisation of bacteriocin genes that harboured in L. plantarum I-UL4 was conducted in this study.
  
  
  CONCLUSIONS
  Under optimised conditions, 8 genes (brnQ1, napA1, plnL, plnD, plnEF, plnI, plnG and plnH) of plnEF locus and 2 genes (plw and plwG) of plw locus were amplified successfully from genomic DNA extracted from L. plantarum I-UL4 using specific primers designed from 24 pln genes selected randomly from reported plw, plS, pln423 and plnEF loci. DNA sequence analysis of the flanking region of the amplified genes revealed the presence of two pln loci, UL4-plw and UL4-plnEF loci, which were chromosomally encoded as shown by Southern hybridisation. UL4-plw locus that contained three ORFs were arranged in one operon and possessed remarkable amino acid sequence of LMG2379-plw locus, suggesting it was highly conserved. Interestingly, the UL4-plnEF locus appeared to be a composite pln locus of JDM1-plnEF and J51-plnEF locus in terms of genetic composition and organisation, whereby twenty complete and one partial open reading frames (ORFs) were aligned and organised successfully into five operons. Furthermore, a mutation was detected in plnF structural gene which has contributed to a longer bacteriocin peptide.
  
  
  CONCLUSIONS
  Plantaricin EF and plantaricin W encoded by plnEF and plnW loci are classified as class I bacteriocin and class II bacteriocin molecules respectively. The concurrent presence of two pln loci encoding bacteriocins from two different classes has contributed greatly to the broad inhibitory spectrum of L. plantarum I-UL4. The new genetic composition and organisation of plnEF locus and concurrent presence of plnEF and plnW loci indicated that L. plantarum I-UL4 is a novel multiple bacteriocin producer that possesses vast potentials in various industries.
authors.affiliation: Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. huifong_tai@hotmail.com.
authors.forename: Hui Fong
authors.initials: HF
authors.lastname: Tai
authors.affiliation: Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. hlfoo@upm.edu.my.|Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. hlfoo@upm.edu.my.
authors.forename: Hooi Ling
authors.initials: HL
authors.lastname: Foo
authors.affiliation: Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. raha@upm.edu.my.|Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. raha@upm.edu.my.
authors.forename: Raha
authors.initials: R
authors.lastname: Abdul Rahim
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. tcloh@upm.edu.my.|Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. tcloh@upm.edu.my.
authors.forename: Teck Chewn
authors.initials: TC
authors.lastname: Loh
authors.affiliation: Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. puad@upm.edu.my.|Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. puad@upm.edu.my.|Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. puad@upm.edu.my.
authors.forename: Mohd Puad
authors.initials: MP
authors.lastname: Abdullah
authors.affiliation: Department of Biofunctional Chemistry, Graduate School of Environmental and Life Sciemce, Okayama University, Okayama, Japan. yosh8mar@cc.okayama-u.ac.jp.
authors.forename: Kimura
authors.initials: K
authors.lastname: Yoshinobu
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001430:Bacteriocins / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D048191:Lactiplantibacillus plantarum / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins; C117244:plantaricin EF