A total of 102 lactic acid bacteria (LAB) were isolated from three different coffee farms in Taiwan. These isolates were classified and identified by the restriction fragment length polymorphism analysis and sequencing of 16S ribosomal DNA. Heterofermentative Leuconostoc, and Weissella species were the most common LAB found in two farms located at an approximate altitude of 800 m. Lactococcus lactis subsp. lactis was the most common LAB found in the remaining farm was located at an approximate altitude of 1,200 m. It is therefore suggested that the altitude and climate may affect the distribution of LAB. On the basis of phylogenetic analysis, two strains included in the genera Enterococcus were considered as two potential novel species or subspecies. In addition, a total of 34 isolates showed the antifungal activity against Aspergillus flavus. Moreover, seven Lactococcus lactis subsp. lactis strains and one Enterococcus faecalis strain were found to have bacteriocin-like inhibitory substance-producing capability. These results suggest that various LAB are associated with fresh coffee cherries in Taiwan. Some of the isolates found in this study showed potential as antifungal agents.

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.

The results demonstrate that various LAB species are distributed in sian-sianzih and have a great effect on the flavor of sian-sianzih.

Enterococcus sp. 812, isolated from fresh broccoli, was previously found to produce a bacteriocin active against a number of Gram-positive bacteria, including Listeria monocytogenes. Bacteriocin activity decreased slightly after autoclaving (121 °C for 15 min), but was inactivated by protease K. Mass spectrometry analysis revealed the bacteriocin mass to be approximately 4,521.34 Da. N-terminal amino acid sequencing yielded a partial sequence, NH2-ATYYGNGVYXDKKKXWVEWGQA, by Edman degradation, which contained the consensus class IIa bacteriocin motif YGNGV in the N-terminal region. The obtained partial sequence showed high homology with some enterococcal bacteriocins; however, no identical peptide or protein was found. This peptide was therefore considered to be a novel bacteriocin produced by Enterococcus sp. 812 and was termed enterocin T.

BackgroundWeissellicin L, a novel bacteriocin produced by Weissella hellenica 4–7, was previously characterized but its full amino acid sequence remain unknown. The draft genome sequencing analysis of Weissella hellenica 4–7 was performed and the open reading frame (ORF) encoding the weissellicin L was identified and clarified.FindingsThe obtained results indicated that the mature bacteriocin consists of 29 amino acid residues with a molecular weight of approximately 3205.64 Da. A conserved processing site of two glycine residues in positions -1 and -2 was observed in the leader peptides. The possibility that bacteriocin secretion depended on ATP-binding cassette (ABC) transporter was therefore suggested. Furthermore, primers were designed from 5’ and 3’ flanking sequences of the weissellicin L structural gene. PCR presented a single product and was useful to detect weissellicin L structural gene.ConclusionsTo our knowledge, this is the first report describing the full amino acid sequence of Weissellicin L. A rapid method to detect weissellicin L structural gene was also reported in this study.