Aim: To identify and characterize novel bacteriocins from Weissella hellenica 4-7. Methods and Results: Weissella hellenica 4-7, isolated from the traditional Taiwanese fermented food sian-sianzih (fermented clams), was previously found to produce a bacteriocin active against Listeria monocytogenes and some other Gram-positive bacteria. Bacteriocin activity decreased slightly after autoclaving (121°C for 15 min), but was inactivated by protease K and trypsin. Mass spectrometry analysis revealed the bacteriocin mass to be approximately 3205Á6 Da. N-terminal amino acid sequencing yielded a partial sequence, NH 2 -KGFLSWASKATSWLVGP, by Edman degradation. The obtained partial sequence showed high homology with leucocin B-TA33a; however, at least two different residues were observed. No identical peptide or protein was found, and this peptide was therefore considered to be a novel bacteriocin produced by W. hellenica 4-7 and termed weissellicin L. Conclusions: The findings obtained in the current study suggest a novel bacteriocin produced by W. hellenica 4-7. Significance and Impact of the Study: Bacteriocins from Weissella remain rare, and this study is the second report of a bacteriocin produced by W. hellenica.

Aim: To isolate and characterize bacteriocin-like inhibitory substance (BLIS)-producing lactic acid bacteria from the intestine of grey mullet. Methods and Results: Inhibitory activity against at least one or more indicator strains was observed in one Enterococcus thailandicus, one Enterococcus faecium and two Lactococcus garvieae strains. Enterococcus faecium B3-8 and Ent. thailandicus B3-22 showed the greatest inhibitory activities against Listeria monocytogenes ATCC 19111 and were therefore further characterized. The results suggested that the inhibitory substances from the two strains showed similar characteristics with respect to sensitivity to heat and proteolytic enzymes. BLIS from Ent. thailandicus B3-22 was characterized by a broader inhibitory spectrum than that from Ent. faecium B3-8. SDS-PAGE revealed that the molecular size of partially purified BLISs from Ent. faecium B3-8 and Ent. thailandicus B3-22 was c. 5 and 3 kDa, respectively. The molecular mass of purified bacteriocin from Ent. thailandicus B3-22 was further determined to be 6319 Da by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The results indicated that BLIS from Ent. thailandicus B3-22 can effectively inhibit the growth of all tested L. garvieae strains. Conclusions: The findings obtained in this study suggest the potential use of Ent. thailandicus B3-22 as a biocontrol agent against pathogenic L. garvieae in the aquaculture. Significance and Impact of the Study: This is the first report describing the characteristics of BLIS from Ent. thailandicus that showed potential for use as a biocontrol agent in the aquaculture.

Aims:  To isolate, characterize and identify lactic acid bacteria (LAB) in the vineyards where koshu grapes, a primary wine grape cultivar in Japan, are grown. Methods and Results:  Sixty samples, including leaves, undamaged grape berries and soil under damaged berries, were collected at four koshu vineyards in Yamanashi Prefecture, Japan. One hundred and 15 acid‐producing cultures were isolated from these samples, and the isolates were divided into classes by phenotype and then into groups by restriction fragment length polymorphism analysis and sequencing of 16S ribosomal DNA (rDNA). Phenotypic and biochemical characteristics identified seven different bacterial groups (A to G). Lactococcus lactis ssp. lactis was the most abundant type of LAB distributed in three koshu vineyards, and Leuconostoc pseudomesenteroides was the most abundant LAB found in the remaining vineyard. Forty‐six isolates produced bacteriocin‐like inhibitory substances (BLIS) against the indicator strain Lactobacillus sakei JCM 1157T. Conclusions:  These results suggest that various LAB are distributed in koshu vineyards, of which a large number produce BLIS. Significance and Impact of the Study:  This is the first report describing the distribution and varieties of LAB that exist in koshu vineyards.

Aims: Purification and characterization of a novel bacteriocin produced by strain Enterococcus faecium D081821. Methods and Results: Enterococcus faecium D081821, isolated from the traditional Taiwanese fermented food dochi (fermented black beans), was previously found to produce a bacteriocin against Listeria monocytogenes and some Gram-positive bacteria. This bacteriocin, termed enterocin TW21, was purified from culture supernatant by ammonium sulfate precipitation, Sep-Pak C 18 cartridge, ion-exchange and gel filtration chromatography. Mass spectrometry analysis showed the mass of the peptide to be approximately 5300Á6 Da. The N-terminal amino acid sequencing yielded a partial sequence NH 2 -ATYYGNGVYxNTQK by Edman degradation, and it contains the consensus class IIa bacteriocin motif YGNGV in the N-terminal region. The open reading frame (ORF) encoding the bacteriocin was identified from the draft genome sequence of Enterococcus faecium D081821, and sequence analysis of this peptide indicated that enterocin TW21 is a novel bacteriocin. Conclusions: Enterococcus faecium D081821 produced a bacteriocin named enterocin TW21, the molecular weight and amino acid sequence both revealed it to be a novel bacteriocin. Significant and Impact of Study: A new member of class IIa bacteriocin was identified. This bacteriocin shows great inhibitory ability against L. monocytogenes and could be applied as a natural food preservative.