ABSTRACT
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 1157(T). 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.
Subject(s)
Lactic Acid/metabolism , Lactobacillus/classification , Lactobacillus/isolation & purification , Lactococcus lactis/classification , Lactococcus lactis/isolation & purification , Leuconostoc/classification , Leuconostoc/isolation & purification , Vitis/microbiology , Antibiosis , Bacteriocins/biosynthesis , DNA Fingerprinting , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Fruit/microbiology , Genes, rRNA , Genotype , Japan , Lactobacillus/metabolism , Lactococcus lactis/metabolism , Leuconostoc/metabolism , Molecular Sequence Data , Phylogeny , Plant Leaves/microbiology , Polymorphism, Restriction Fragment Length , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Sequence Homology, Nucleic Acid , Soil Microbiology , WineABSTRACT
AIMS: To investigate the effects of two prebiotics and trehalose on the production of bacteriocins. METHODS AND RESULTS: Four carbohydrates [dextrose, fructo-oligosaccharides (FOS), raffinose, and trehalose] were used as the sole carbon source in a simple broth. Five bacteriocin-producing strains of bacteria, including those producing nisin, enteriocin, and other bacteriocins, were used, and their inhibitory activities when grown on each carbohydrate were determined. The inhibitory activity assay was performed using the agar well diffusion method, and Lactobacillus sakei JCM 1,157(T) was used as the indicator strain. Effective enhancement of bacteriocin production was observed with FOS and trehalose incubation. CONCLUSIONS: The results suggest that FOS and trehalose can effectively enhance the production of the five kinds of bacteriocins evaluated in this study. SIGNIFICANCE AND IMPACT OF THE STUDY: This study offers useful information for not only a new application of FOS and trehalose, but also the potential improvement of food preservation.
Subject(s)
Bacteriocins/biosynthesis , Lactobacillus , Oligosaccharides/pharmacology , Streptococcaceae , Trehalose/pharmacology , Bacteriocins/pharmacology , Biotechnology/methods , Food Preservation/methods , Lactobacillus/drug effects , Lactobacillus/growth & development , Lactobacillus/metabolism , Microbial Sensitivity Tests , Oligosaccharides/metabolism , Streptococcaceae/drug effects , Streptococcaceae/growth & development , Streptococcaceae/metabolism , Trehalose/metabolismABSTRACT
AIMS: To characterize bacteriocin-like inhibitory substances (BLIS) from two dochi-isolated Enterococcus faecium. METHODS AND RESULTS: Enterococcus faecium D081821 and D081833 were isolated from dochi (a traditional fermented food in Taiwan) and found to produce BLIS with inhibitory activities against Listeria monocytogenes, Clostridium perfringens, and Bacillus cereus. Strains D081821 and D081833 showed different growth temperatures and their BLIS showed different sensitivities to heat, proteolytic enzymes, and antibacterial spectra. Both BLIS were collected, partially purified, and analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE showed that both partially purified BLIS were approximately 3.0 kDa in size. CONCLUSIONS: These results indicate that E. faecium D081821 and D081833 produce different BLIS with strong antibacterial actions against the tested pathogenic bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study suggest that two different BLIS from dochi-isolated lactic acid bacteria have potential for use as food preservatives.
